Metabolism definition. Metabolism - what is it in simple terms, how to speed up or slow down metabolism? Exercises to speed up your metabolism

According to the theory, supported by scientists from different countries, each person has his own optimal weight, which the body tries with all its might to maintain. That is why the persistent desire to gain weight causes active resistance on the part of the body, and it will do everything possible to bring the weight back closer to its normal level. natural meaning. That's why 95% of people who lose weight gain weight again. Their new weight relatively low for a “normal” individual metabolism. For the vast majority of people, the body's resistance to weight loss is stronger than to weight gain, that is, it will always strive to preserve stored fat reserves. The calorie content of food can even slow down the metabolic rate by 45%. Perhaps this is defense mechanism body from starvation.

However, not all scientists support this theory. And although they do not contradict the theory of the natural optimal weight, but they believe that metabolism can be changed by a certain diet and regular physical activity, which increases muscle mass and facilitates the breakdown of fat. But first of all, it is necessary to find out what metabolism is and what are the principles of its action.

Metabolism- these are chemical reactions that occur from the moment nutrients enter the body until the end products of these reactions are released into the external environment. This difficult process converting food consumed into vital energy. Metabolism involves all reactions occurring in living cells, which result in the construction of tissue and cell structures. That is, metabolism can be considered as the process of exchange of substances and energy in the body.

A living cell is a highly organized system, including various structures, as well as special enzymes that can destroy these structures. The macromolecules contained in the cell can break down into small components through hydrolysis. The cell usually has very little and a lot of potassium, while it exists in an environment where there is little and a lot of sodium, and the permeability of the cell membrane for both ions is the same. Hence the conclusion: a cell is a system very far from chemical equilibrium.

To maintain a cell in a chemically unbalanced state, the body needs to perform certain work, which requires energy. Obtaining energy to perform this work is an indispensable condition for the cell to remain in its normal stationary chemically unbalanced state. At the same time, other work is performed in the cells to interact with the environment, for example: conducting nerve impulses in nerve cells, muscle contraction - in muscle, urine formation in kidney cells, etc.

Nutrients, once inside the cell, begin to be metabolized, or undergo many chemical changes and form intermediate products - metabolites. The metabolic process is broadly divided into two categories: anabolism and catabolism. During anabolic reactions, complex molecules are formed from simple molecules through biosynthesis, which is accompanied by the expenditure of free energy. Anabolic transformations are usually restorative. In catabolic reactions, on the contrary, complex components supplied with food and included in the cell are broken down into simple molecules. These reactions are predominantly oxidative, accompanied by the release of free energy.

The bulk of calories from food is spent on maintaining body temperature, digesting food, internal processes the body is the so-called basic metabolism.

The direct source of energy used by the cell to produce work is the energy contained in the molecule adenosine triphosphate (ATP). Due to some of its structural features, the ATP compound is rich in energy, and the cleavage of phosphate group bonds that occurs during the metabolic process is carried out in such a way that the released energy can be used. However, as a result of simple hydrolysis, breaking the phosphate bonds of the ATP molecule will make the energy released for the cell unavailable, since the metabolic process must sequentially consist of two stages with the participation of an intermediate product in each of them, otherwise the energy is released in the form of heat and is wasted. The ATP molecule is necessary for almost all manifestations of cell activity, therefore, it is not surprising that the activity of living cells is primarily aimed at the synthesis of ATP. This process consists of complex sequential reactions using potential chemical energy contained in molecules.

Anabolism is closely related to catabolism, since new substances are obtained from the breakdown products of nutrients. If anabolism is aimed at the formation of composite structures of cells and tissues, then catabolism transforms complex molecules into simple ones. Simple molecules are partially used for biosynthesis (the formation of organic substances from simple compounds under the action of biocatalyst enzymes), and are partially excreted from the body in the form of breakdown products such as urea, ammonia, carbon dioxide and water.

The speed of the metabolic process varies from person to person. The most important factor influencing metabolic rate is body weight, or rather the total mass of muscles, internal organs and bones. The greater your body weight, the higher your metabolic rate. Metabolic processes in men proceed, on average, 10-20% faster, this is due to the presence in women more fat deposits, while in men muscle tissue more. According to scientists, the metabolism of women who have crossed the 30-year mark decreases by 2-3% every next ten years. However, not only women, but also men are at risk of metabolic decline with age. As a rule, this is due to a lack motor activity and hormonal imbalance. You can speed up your metabolism with the help of fractional meals. with increasing physical activity, it significantly slows down the metabolic process - the body prepares for possible starvation and begins to intensively accumulate fat.

Metabolism is also directly influenced by factors such as heredity and work. thyroid gland. With a lack of the thyroid hormone L-thyroxine, metabolism is markedly reduced, which causes “unexplained” obesity. With an excess of this hormone, on the contrary, metabolism accelerates so much that it can threaten physical exhaustion. It is noteworthy that in both cases there is a catastrophic lack of vital energy.

According to research, the condition emotional background directly affects the production of hormones. In the stage of excitement or excitement, the hormone adrenaline is released into the blood, increasing the metabolic rate. And in a state, hundreds of calories are burned per day. However, no matter how paradoxical it may seem, chronic stress leads to obesity. The thing is that in a state of stress, the adrenal glands release a large amount of the hormone cortisol into the blood, and it helps to increase blood sugar levels and, if sugar is not used, it quickly passes into fat reserves.

Few people manage to maintain their constant weight throughout their lives, so fluctuations in one direction or another are most likely the rule. If you do not attach great importance to short-term minor fluctuations in weight, then the approximate graph looks like this: at 11-25 years of age there is a minimum weight with a high energy needs; at 25-35 years of age, weight stabilizes and begins to gradually creep up until approximately 65 years of age, and then begins to decline. However, this is a very average picture, since each person is individual and has his own metabolic process unique to him.

Hi guys! First of all, congratulations on the first day of summer! Summer is just awesome! A completely different mood appears, you want to work less and less, you feel the approach of a long-awaited vacation. Strawberries and cherries are already being sold at the market - by the way, how many of you have already taken a “vitamin” with this goodness this year? I have already!

But today I would like to discuss with you the topic of accelerating metabolism. This will be very important for all of us, but especially for those who are planning to lose excess weight. I have already raised a similar question on the pages of my blog. There is an excellent article on the topic. I highly recommend it for study, since we are talking about this!

Many people who want to lose weight fail to achieve their goal, even if they do everything right. The reason for this may be insufficiently fast metabolism (metabolism). This is such a vital process that determines the speed of vital reactions in the human body. Thanks to this article, you will learn what effect metabolism has on getting rid of extra pounds and how you can increase its speed.

As usual, we will discuss everything briefly, informatively and without unnecessary fluff. And if anything is unclear, use the comment form below. Yes, I almost forgot - if suddenly the question arose about slowing down the metabolism in order to gain weight -

The speed of metabolic processes is naturally influenced by several factors, but one of the mega-important ones is nutrition. There are a number of rules on how to start metabolism for weight loss that must be followed. Let's pay attention to them:

You can't ignore your morning meals. A hearty breakfast is the key to starting your metabolism. In general, no one canceled oatmeal for breakfast and a couple of eggs, so don’t even think about it...
You need to stick to fractional meals, eating at least five times a day every 2.5-3 hours. If the time intervals increase, the body will receive a signal to switch to energy saving mode, slowing down the metabolism. Although now you can already find information on the Internet that disputes the effectiveness frequent meals to speed up metabolism - nevertheless, THIS METHOD WORKS!
Can't stick strict diets and even more so starve. If the body does not receive enough energy per day, and this is at least a thousand kilocalories, it will begin to make reserves in the form of subcutaneous fat, while slowing down metabolic processes up to 30%.
Many people mistakenly ignore the rule of maintaining water balance and are surprised when they cannot lose weight. Without sufficient weight loss and normal metabolic rate are impossible. Drinking cold or melted water will help speed up this process, because in order to assimilate it, the body will have to “warm it up” to body temperature, spending energy on this. But don’t drink cold water in the hot summer, otherwise the neck may “bo-bo”. Keep the norm to two liters per day.
It is necessary to diversify the range of foods and change the amount of calories consumed per day. If the number does not change, the body will get used to it and the metabolism will slow down. Don’t be afraid to give your body a shake-up and increase your diet by 200-300 calories once a week.
If you want to burn fat, then you will have to give up bad habits and unbalanced nutrition. This is especially true for alcohol, carbonated drinks, processed foods, fast food, chips and other unhealthy foods.

Scientific studies have confirmed that alcohol abuse slows down metabolism by almost 75%.

What should you include in your diet?

Food rich in proteins. The body spends the most time and energy on digesting and assimilating protein, and this has a beneficial effect on the launch of metabolism. It is also protein that is involved in the processes of burning fat and building muscle mass. Protein should dominate your diet and be part of every meal. This is especially important for breakfast. More content on this useful substance in fish, seafood, chicken breast, turkey, legumes, eggs and dairy products.

Foods rich in fiber will help speed up your metabolism by up to 10%. They help maintain insulin levels for a long time in the same range, and this prevents the accumulation of fats and keeps you full for several hours. This includes vegetables, fruits, grains and beans.

Foods high in omega-3 fatty acids. They help balance the content of leptin, a substance that determines the rate of metabolism and “makes decisions” for or against the accumulation of fat. Large amounts of these acids are found in fatty fish - trout, mackerel, tuna, salmon and products plant origin– in flax seeds, walnuts, beans.

Foods rich in folic acid. In addition to increasing the metabolic rate, they remove harmful substances from the body and strengthen the immune system. These include eggs, carrots, liver, and wheat bran.

I eat, with increased number chromium. Thanks to this microelement, sugar levels in the body are reduced, and it also takes part in the burning of fats and carbohydrates. It can be found in vegetables - corn, cabbage, tomatoes, onions, in cereals - buckwheat, oats, wheat and legumes.

Products containing iodine. This trace element is vital for the normal functioning of the thyroid gland, which in turn is responsible for regulating metabolism. Sources of iodine are seafood– kelp, fish, crabs, squid, oysters.

Food with a high calcium content. In addition to the well-known function of forming and strengthening teeth and bones, calcium also affects the digestion of food and the absorption of nutrients. Its main sources are dairy products, rose hips, almonds, sesame seeds, and beans.

Metabolism booster foods

Citruses. They are an indispensable part of the diet not only for losing weight, but also for improving immunity. Grapefruits, oranges, lemons have a beneficial effect on the digestive system, remove toxins and excess liquid, and also lower cholesterol.
Green tea. Thanks to two main components - caffeine and catechin, it improves and accelerates the digestion process, increasing the amount of energy required for this. Daily use Three cups of this drink can improve your metabolic rate by almost 5%.
Coffee. Thanks to the increased caffeine content, it accelerates metabolic processes and energizes you, helping you to be more productive in your workouts.
Honey. One teaspoon of honey per glass of water with added lemon juice helps to effectively start metabolism when consumed on an empty stomach.
Ginger. Helps to better absorb beneficial elements and saturate tissues with oxygen.
Cinnamon. Significantly lowers blood sugar levels while increasing metabolic rate. Regular consumption of this seasoning helps in weight loss.
Red pepper, chili and jalapeno. Thanks to a special substance – capsaicin, heart function and metabolism are accelerated, effectively burning calories for a long time after consumption.
Garlic. Particularly useful when eating fatty foods, reducing the likelihood of fat deposits. Also balances glucose levels.
Apples. It stimulates the gastrointestinal tract well and has a positive effect on metabolism.
Oatmeal. Thanks to high content fiber, the body spends a large amount of energy on its digestion.
Apple vinegar. Helps break down fats that enter the body with food.
Broccoli. It is an excellent combination of calcium, vitamin C and fiber.

We accelerate metabolism with sports

The second mega-important metabolism booster is sport. Bodybuilding, fitness or whatever you do. There are a few general rules for physical activity:

Gradual increase in load.
It is necessary to eat food an hour and a half before the start of classes.
You cannot breathe through your mouth, otherwise the tissues will not be saturated with oxygen.
Do a variety of workouts different groups muscles, this will keep your metabolism in good shape.

The most effective way to achieve your goal will be AEROBIC exercise. They increase the number of heart contractions and increase the speed of metabolic processes. Also, after finishing the workout, calories are burned for another 12 hours.

Aerobic exercises include:

Walking. This type of training is suitable even for unprepared people and is available to everyone without exception. Start at an accelerated pace, gradually increasing the distances covered.
Run. It is very useful to speed up the metabolism by doing periodic accelerations. For example, run for 2 minutes at a normal pace, and one at an intense pace, and so alternate up to 5 times. Be sure to monitor your heart rate when running and other aerobic exercise. - a very important factor in successful fat burning.
Swimming.
Jumping rope. My favorite type of “puffing” loads. I love jump rope! Be sure to set yourself a goal not just to jump, but to learn to jump more professionally. With double scrolling in one jump, cross to cross, etc.
Run. If you don't like running outside, a treadmill is a great alternative. A treadmill is better for this.
Biking, roller skating or skating. As you can see, in principle, any type of exercise where you sweat and force your “engine” to work actively is suitable.

If you want to burn fat in the right heart rate range, you can’t do without a professional heart rate monitor, which can also synchronize with your smartphone via Bluetooth. You can check it out HERE.

No less effective are strength loads that stimulate the growth of muscle mass - these loads are called ANAEROBIC. For quality training with iron, it is better to visit a well-equipped, modern gym. But if you wish, you can train at home and find minimal opportunities for this. Suitable for this:

Squats that simulate sitting on a chair. You need to keep your back straight and your feet shoulder-width apart.
Lunges. They use a whole group of muscles and develop coordination. Keeping your back straight, step forward with your knee bent at a right angle. Lower your other leg as low as possible without touching the floor.
Pushups.
Abdominal exercises.
Plank.

Perform strength exercises up to 3 times a week, alternating with aerobic exercises. You also need to constantly increase the intensity of your workouts by using weights or increasing the number of approaches.

Factors that negatively affect metabolism

Genetic predisposition. A slow metabolism can be inherited. Sometimes this can begin to manifest itself after an illness, a nervous shock, or pregnancy.
Age. The older a person is, the slower the speed of processes and reactions in the body.
Hormonal disorders. Improper functioning of the thyroid and pancreas leads to a slowdown in metabolism.
Bad habits. Alcohol and smoking negatively affect the entire body as a whole, poisoning almost every cell. They also have a detrimental effect on metabolic processes and interfere with weight loss.
Insufficient physical activity. Even if you find it difficult to find the time, energy or desire to go to the gym or exercise at home, you can compensate for this with simple exercise. For example, walking to work or not using the elevator.
Constantly being under stress. Constant fatigue and nervous experiences lead to the release of fatty acids, which are transformed into body fat. Try to avoid excessive anxiety and rest mentally and physically.
Chronic lack of sleep. Sleeping less than 7.5 hours a day leads to a failure in biological rhythms, decreased metabolic rate and weight gain.

Additional methods

Visiting a bathhouse or sauna. Having warmed up with steam, the skin opens all pores, increasing blood circulation and metabolism. This is also a great way to burn subcutaneous fat, reduce pain syndrome in muscles and relaxation. We just can’t forget about replenishing fluids. About combining sauna and bodybuilding
Cold and hot shower. It will give you an excellent boost of energy for the whole day, make your skin smooth and elastic, and also speed up metabolic processes. Alternate hot and cold water for half a minute. Finish the procedure with low temperature water, and then rub thoroughly with a towel.
Bath. Taking a bath with various supplements will help improve your metabolism. You can add herbal decoctions with linden, lavender, rosemary. Also good effect give baths with mustard and essential oils of orange and juniper.

Massage. You can visit professionals or do massage yourself using special massagers, vacuum jars and using warming creams and oils, as well as honey. Massage increases blood circulation and removes excess fluid, thereby giving the desired effect.
The use of essential oils with care products. Their addition to scrubs, mixtures for wraps, as well as massage oils increases the effect of the procedures. The most beneficial oils for metabolism are cypress, orange, grapefruit, juniper, geranium and cinnamon.
Get enough sleep. For normal speed metabolic processes, a person needs 7-8 hours of sleep without interruptions. In addition, going to bed should be no later than 11 o’clock, because it is from 11 to 1 am that fats are most actively burned and growth hormone is released.
Staying outdoors. This can be combined with walking and stroll for several hours in parks and forest parks. This will saturate the body with oxygen, charge it with vitamin D and lift your spirits.
Folk remedies. Use herbal decoctions based on chamomile, St. John's wort, yarrow and many others can significantly improve metabolism.

Interesting scientific data

Scientists have conducted a number of studies, finding that the metabolic rate is determined from birth and largely depends on the type of body constitution. Metabolism is faster in those who have a more developed muscular system, And total weight body, including the skeleton and internal organs. Therefore, men have a higher metabolic rate.

Also, numerous data confirm that upon reaching 30 years of age, metabolic processes begin to slow down by 3-4% every 10 years.

Also, expert opinions differ regarding the effect of specific foods on metabolism, but they agree on one thing - frequent split meals have a more beneficial effect.

Medicines

Taking pills and other medications is justified only when no other methods help. To select medications, you need to consult your doctor. Sometimes application is enough complex vitamins, because in this article we found out that the lack of many of them leads to a slowdown in metabolism.

Safe pharmaceutical products are herbal preparations based on:

Lavzea safroliformes
pink radios
Eleutherococcus
ginseng
and lemongrass

Products based on the amino acid L-carnitine are also effective, but it only acts in tandem with physical activity.

There are also many dietary supplements on the market that have a stimulating effect on metabolism and can be really effective, but they have many contraindications and side effects.

Metabolism is a rather complex process, and any disruption to its normal course can affect health and appearance. If you're having trouble losing weight, try the tips in this article.

And that’s all I have. Speed up your metabolism if you need it and lose weight, since you have set such a goal for yourself. And I wish you patience in this and, albeit not super-cool, but stable and concrete results. Bye bye!

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Slow metabolism is the basis of many health problems, such as obesity and type 2 diabetes. That's why it's so important to know how to speed up your metabolism.

Slow metabolism is the basis of many health problems, for example, obesity or type 2 diabetes. That's why it's so important to know how to speed up your metabolism.. But first, let's figure out what processes are characteristic of metabolism, what symptoms indicate a decrease in the speed of metabolic processes.

How to speed up your metabolism - 7 methods

1. Metabolism - what is it? in simple language?
2. Types of metabolic rate
3. Factors affecting metabolic rate
4. Is it true that some people have an accelerated metabolism from birth?
5. Symptoms of metabolic disorders in women and men
6. What slows down your metabolism?
7. Strict diets
8. Foods that slow down your metabolism
9. How to speed up your metabolism?
10. Down with the calorie-counting diet.
11. Normalization of sleep
12. Optimizing physical activity
13. High intensity interval training (HIIT)
14. Power loads

Metabolism - what is it in simple terms?

Metabolism, or metabolism, is a term that describes the entire set of biochemical reactions occurring in the body. Metabolism is characterized by two types of reactions:

catabolism– the process of destruction of molecules with the release of energy;

anabolism- the process of creating large biological molecules from smaller components entering the body from the outside.

Nutrition is the basis of all metabolism. Some molecules enter the body with food and decompose there, releasing energy. This energy is used for the synthesis of other molecules that are necessary for life - proteins, nucleic acids, neurotransmitters, etc.

However the function of molecules entering the body with food is not only to provide energy, but also to ensure the supply of all those substances that are necessary for the synthesis of the body’s own molecules.

That is for normal life The correct amount of elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, calcium, potassium, sodium, zinc, etc. must be supplied with food. As well as chemical compounds - amino acids, fatty acids, some carbohydrates, vitamins, etc.

Every organ system from the endocrine to the digestive depends on how quickly cells can produce energy. And the more active the metabolism, the higher the immunity, better fertility and sexual health, more long life etc.

Types of Metabolic Rate

Basal or main. This is the minimum metabolic rate that occurs at complete rest, for example, in a state of sleep.

Speed at rest. The person does not sleep, but does not move either - he lies or sits quietly. Typically, this type of metabolism accounts for 50-70% of the calories burned per day.

Thermal effect of food. This is the number of calories that the body spends on digesting food. As a rule, 10% of all resources burned per day.

Warm effect physical exercise . The number of calories burned during intense physical activity.

Non-sports thermogenesis. The number of calories expended on non-intense physical activities - walking slowly, maintaining vertical position body, change in posture.

Factors affecting metabolic rate

Age. The older a person is, the slower metabolic processes occur.

Amount of muscle mass. The more muscles, the faster the metabolism.

Body size. The larger a person is, the faster his body burns calories.

Temperature environment . The colder it is, the more calories are burned.

Physical activity.

Hormonal status. Many hormonal disorders capable of extremely strong changes in metabolic rate.

Is it true that some people have a faster metabolism from birth?

No it is not true. Often people who are overweight complain that their metabolism is naturally so slow. So they get fat before our eyes and from the air. But for those who have normal body weight, everything burns out, because the metabolism genetically has a huge speed. This is a very convenient theory for self-justification when you are overweight. But it is not supported by anything scientifically. On the contrary, there has been evidence that people with overweight often have more high speed metabolism. Other studies have shown that fat people the metabolic rate may be slightly slower than that of their normal-sized peers, but no more than 8%.

Symptoms of metabolic disorders in women and men

We tend to think that a low metabolic rate is primarily due to overweight. Definitely connected. However, the organ that suffers the most from slowing metabolic processes is the brain. This may seem strange, but the brain spends 16 times more energy on its work than skeletal muscles need to maintain its vital functions. Therefore, the signs of a decrease in the rate of metabolic processes are very polymorphic, and many of them are associated specifically with the demonstration of neurological symptoms. Signs of metabolic disorders and slowdowns in women and men are largely the same. However, there are also differences. For example, women often experience disruptions in the menstrual cycle, as well as changes in the appearance of cellulite.

Problems with excess weight:

body weight has increased, and it cannot be reduced in any way; all the methods that once worked no longer help;
inability to lose weight, even with regular physical activity, for example, fitness classes 5 times a week;
inability to lose weight even with a very strong restriction of calories entering the body, sometimes practically during starvation;
big belly;
accumulation of fat in areas of the body where this has not been observed before.

Allergic, immune and general:

chronic fatigue;
decreased body temperature;
constant feeling of cold;
allergies;
strange hypersensitivity to certain foods, etc.;
inability to force yourself to be physically active;
constant colds.

Related to the work of the gastrointestinal tract:

chronic constipation or diarrhea;
frequent bloating abdomen and flatulence;
excessively strong rumbling in the stomach after eating;
slow digestion (you may feel heaviness in your stomach in the evening from what you ate at lunch);
heartburn.

Mental and neurological:

restless night sleep;
depression and/or anxiety;
problems with concentration;
life, as in a dream, some confusion of consciousness;
dizziness;
increased sensitivity to bright light and loud sounds;
high irritability.

Dermatological:

Thin hair;
thin skin that cracks easily (especially on the heels);
brittle, slow-growing nails.

Relating to the sexual sphere:

decreased libido;
impotence in men;
frigidity in women;
disruption of the menstrual cycle in women.

Changes in eating behavior: except high feeling hunger, characteristic feature a decrease in the rate of metabolic processes is a craving for sweets, which is especially acute at noon. K typical feminine characteristics impaired slow metabolism refers to a change in the nature of the localization of cellulite deposits. Cellulite on the buttocks, back and sides of the thighs is completely normal and does not indicate any health problems. But if cellulite begins to manifest itself on the front surface of the thighs, abdomen, arms, this already indicates that the metabolism is slowed down.

Sometimes a decrease in metabolic rate can show dry mouth and constant thirst , not associated with the inclusion of large amounts of salty and spicy foods. This symptom is similar to diabetic, but can also manifest itself without severe diabetes.

Little-known signs of decreased metabolic rate include drooping shoulders and increased stooping.. This symptom is more clearly noticeable in men, especially in those who previously had a fairly well-developed shoulder girdle.

If you have found a fair amount of the above signs of a slow metabolism, then most likely this problem actually exists in your life. But don't despair. It's treatable. You can speed up your metabolism, even on your own at home.

To understand how to restore metabolism in the body, you must first identify the main factors that lead to disruption of metabolic processes.

Strict diets

Despite the fact that scientists have proven that counting calories for proper weight loss is virtually useless, many people continue to torture themselves with strict diets, count calories and do not receive a significant amount of nutrients. And as a result, slow down your metabolic processes.

Why is this happening? Very simple. Metabolism depends entirely on the intake of nutrients into the body. Without them, energy production and synthesis of molecules of the body itself are impossible. If you significantly reduce the amount of calories entering the body, then at the same time you will have to reduce the amount of nutrients.

Fat burning in such conditions will be reduced by the body to a minimum, because it will assess the situation as hunger, which can lead to death. And it will begin to save itself by minimizing energy consumption, that is, by slowing down metabolic processes.

Your body doesn’t care at all why you don’t feed it: because you want to lose weight, or because you are in a besieged city. He knows one thing - there is not enough food. And, therefore, it is necessary to switch to the strictest economy of all resources, including fat deposits.

By the way, it is the extremely strong restriction of calories entering the body per day that is one of the reasons for the plateau effect when losing weight.

Foods that slow down metabolism

All sweets. Everything means everything. Including “healthy natural ones”. This is due to the fact that all sweet compounds lead to “metabolic confusion” and therefore slow down metabolism. Of course, the severity of the negative impact on metabolism varies among different sweet foods.

So the most dangerous are regular table sugar, fructose(and many “naturally healthy” products containing it, such as fruit juices) and artificial sweeteners. And natural substitutes sugars, which in their essence are not any substitutes, but are the same table sugar and fructose only under different names. Such sweeteners include agave nectar or maple syrup. Other natural sugar substitutes, such as stevia or erythritol, are less harmful. But they also slow down your metabolism.

Cereals. Almost everyone understands that some buns and pasta do not help you lose weight and clearly do not boost your metabolism. However, many people mistakenly believe that food made from whole grains only enhances metabolism. Unfortunately, it is not . For all grains contain (in varying quantities and proportions) three unhealthy ingredients:

gluten, which is very harmful to the body;
starch, which easily turns into sugar;
phytic acid, which prevents the absorption of certain microelements, that is, it imitates hunger for the body, against the background of which it slows down metabolism.

Many vegetable fats and trans fats

Most vegetable oils, especially those that are inexpensive and very widespread, for example, sunflower or rapeseed oil, extremely harmful to the body A. They actually disrupt your entire metabolism. Similar effect Trans fats also have it.

How to speed up your metabolism?

Down with the calorie-counting diet! It has already been explained in detail above why a diet that strictly limits the number of calories leads to a slowdown in metabolism and, as a result, to an increase in body weight. So, giving up such strict diets is prerequisite accelerating metabolism. And here it is very important to note that all those who give up diets and allow their body to absorb as many calories as it needs will receive an additional “bun”, namely the development of more correct attitude to food. It has been established that people who do not subject their bodies to periodic long-term fasting(read – diets), have less tendency to constantly snack and give up sweets more easily.

Normalization of sleep

Lack of rest affects metabolism in the same way as lack of food - it slows it down. The explanation is again simple. The body believes that it is under conditions of extreme stress, which can be dangerous for its very existence. And it begins to save energy, slowing down metabolic processes. Therefore, if you notice signs of a slow metabolism, you should immediately pay attention to your sleep. And if there are obvious problems with night rest, do your best to normalize it. To do this, you can try to increase the level of the sleep hormone melatonin.

Optimizing physical activity

Quite often, symptoms of a slow metabolism can be found in young people who try to lead a so-called healthy lifestyle and, for the sake of this, torture themselves with physical activity. Fitness is useful, including for losing weight. This is undeniable. But only physical activity should be normal. Overtraining slows down your metabolism in the same way that lack of sleep and crash diets do. The body also enters a state of stress and begins to conserve energy.

Moreover, with overtraining, the level of the stress hormone cortisol increases in the blood. And against this background, insulin sensitivity decreases, which inevitably leads to excess weight gain. Therefore, to improve your metabolism and lose weight, exercise in moderation. To the best of my ability. That is, you don’t need to train when you have not yet recovered from the previous session, when your muscles hurt, or you simply don’t have the strength in them. And don’t look at your friends and girlfriends who trained with you last time, and today they are already jumping briskly. Each person has their own recovery rate.

High Intensity Interval Training (HIIT)

In the very beginning of XXI centuries, scientists have proven that high-intensity interval training is much more effective in helping to accelerate metabolism and lose weight than classic fitness classes, such as traditional cardio training. This is due to the hormonal response that the body forms in response to physical activity.

Power loads

When men engage in fitness, no matter for what purpose, they do not shy away from strength training. But women often have problems with this type of physical activity, since for some reason women believe that they not only do not need strength training. They are dangerous for them, as they will lead to an increase in body size and restructuring of the body according to male type. Of course, this is a fallacy. And very harmful. Since it prevents fitness classes from doing the job for which they are aimed - speeding up metabolism and getting rid of excess fat deposits.

The fact is that without strength training it is extremely difficult to build muscle. And without a significant amount of muscle mass, it will not be possible to accelerate metabolism, since muscles in many ways ensure the rapid passage of metabolic processes.

Therefore, both men and women must pay attention to strength training when doing fitness.. And in order for representatives of the weak half of humanity to rebuild themselves in a masculine way, they must accept hormonal drugs. It just won't happen on its own.

If you want to speed up your metabolism, you will have to give up sweets and carbohydrates. If it is not possible to completely eliminate sweets, it is necessary to at least replace them with the least harmful options - stevia.

First of all, this is - protein products , since they have a very high thermal effect and therefore accelerate the metabolism.

Green tea and black natural coffee– two drinks that are well known for their ability to improve metabolism.

Garlic, as well as meat products, has a high thermal effect.

Warming spices- These are products that speed up metabolism and burn fat. They also demonstrate good thermogenic qualities. Cinnamon, ginger, turmeric work.

Foods that have a low glycemic index but are highly filling. These are nuts and seeds, legumes, all types of cabbage and other leafy green vegetables, tomatoes, eggplants.

All these products, primarily nuts, contribute to the production of pancreatic polypeptide PPY, which replaces a person’s cravings for sweets and other carbohydrates and fats. At the same time, the rate of burning fat deposits significantly increases.

This action is opposite to the influence of hunger hormones, which, on the contrary, force a person to eat more carbohydrates.

Metabolism consists of two parts: catabolism - the destruction of compounds entering the body, and anabolism - the synthesis of its own molecules. In order for the metabolic rate to be high, the body must receive all the substances and energy it needs. Therefore, for a fast metabolism, you need to eat well, and not go on strict diets and torture yourself with physical activity. Many unhealthy foods can significantly slow down your metabolism. Therefore, everyone who wants to speed it up should completely remove these harmful products from their diet and replace them with products that speed up metabolism and ensure fat burning. published.

Any questions left - ask them

P.S. And remember, just by changing your consciousness, we are changing the world together! © econet

Text: Olga Lukinskaya

THE WORD “METABOLISM” IS OFTEN USED IN APPROPRIATE AND INAPPROPRIATE, but not everyone fully understands what metabolism is and according to what laws it functions. To figure this out, we asked sports nutritionist, member of the International Sports Science Association (ISSA) Leonid Ostapenko and clinical psychologist, founder of the Eating Disorders Clinic Anna Nazarenko, what you need to know about metabolism and how not to harm your body in trying to change it.

What is metabolism

Metabolism, or metabolism, combines all chemical reactions in the body. They occur continuously and include catabolism - the breakdown of proteins, fats and carbohydrates to produce energy and "building materials" - and anabolism, that is, the creation of cells or the synthesis of hormones and enzymes. Our skin, nails and hair and all other tissues are regularly renewed: to build them and restore them after injuries (for example, to heal wounds), we need “building blocks” - primarily proteins and fats - and “workforce” - energy. All this is called metabolism.

Metabolism refers to the turnover of energy necessary for such processes. Its expenses during the main metabolism are calories, which are spent on maintaining body temperature, functioning of the heart, kidneys, lungs, nervous system. By the way, with a basic metabolism of 1,300 kilocalories, 220 of them are spent on brain function. Metabolism can be divided into main (or basal), which occurs constantly, including during sleep, and additional, associated with any activity other than rest. All living organisms, including plants, have a metabolism: it is believed that the hummingbird has the fastest metabolism, and the sloth has the slowest.

What affects metabolic rate

We often hear the expressions “slow metabolism” or “fast metabolism”: they often mean the ability to stay slim without restrictions on food and exercise, or, conversely, the tendency to gain weight easily. But metabolic rate is reflected not only in appearance. People with fast metabolisms spend more energy on vital functions such as the heart and brain in the same amount of time than those with slow metabolisms. With equal loads, one person can have croissants for breakfast and lunch, instantly burning all the calories received, while the other will rapidly gain weight - this means that they have different speed basal exchange. It depends on many factors, many of which cannot be influenced.

Metabolic factors that cannot be corrected are called static: these are heredity, gender, body type, age. However, there are conditions that can be influenced. These dynamic parameters include body weight, psycho-emotional state, diet organization, level of hormone production, physical activity. The speed of exchange depends on the interaction of all of the above. If you correctly adjust the factors of the second group, you can speed up or slow down your metabolism to some extent. The result will depend on the characteristics of genetics and the stability of the entire metabolic system.

General understanding of the metabolism of organic substances.
What is metabolism? Metabolism concept. Research methods.
Metabolism - meaning of the word.Metabolism of carbohydrates and lipoids.

Protein metabolism

METABOLISM is metabolism, chemical transformations that occur from the moment nutrients enter a living organism until the moment when the final products of these transformations are released into the external environment. Metabolism includes all reactions that result in the construction of the structural elements of cells and tissues, and processes in which energy is extracted from substances contained in cells. Sometimes, for convenience, two sides of metabolism are considered separately - anabolism and catabolism, i.e. processes of creation of organic substances and processes of their destruction. Anabolic processes are usually associated with the expenditure of energy and lead to the formation of complex molecules from simpler ones, while catabolic ones are accompanied by the release of energy and end with the formation of metabolic end products (wastes) such as urea, carbon dioxide, ammonia and water.

Cellular metabolism.

A living cell is a highly organized system. It contains various structures, as well as enzymes that can destroy them. It also contains large macromolecules, which can break down into smaller components as a result of hydrolysis (splitting under the influence of water). The cell usually has a lot of potassium and very little sodium, although the cell exists in an environment where there is a lot of sodium and relatively little potassium, and the cell membrane is easily permeable to both ions. Consequently, a cell is a chemical system that is very far from equilibrium. Equilibrium occurs only in the process of post-mortem autolysis (digestion itself under the influence of its own enzymes).

Energy requirement.

To keep a system in a state far from chemical equilibrium, work must be done, and this requires energy. Receiving this energy and performing this work is an indispensable condition for the cell to remain in its stationary (normal) state, far from equilibrium. At the same time, other work related to interaction with the environment is performed in it, for example: in muscle cells- reduction; in nerve cells - conduction nerve impulse; in kidney cells - the formation of urine, which differs significantly in composition from blood plasma; in specialized cells of the gastrointestinal tract - synthesis and secretion digestive enzymes; in the cells of the endocrine glands - secretion of hormones; in firefly cells - glow; in the cells of some fish - generation of electrical discharges, etc.

Energy sources.

In any of the above examples, the immediate source of energy that the cell uses to produce work is the energy contained in the structure of adenosine triphosphate (ATP). Due to the nature of its structure, this compound is rich in energy, and the breaking of bonds between its phosphate groups can occur in such a way that the released energy is used to produce work. However, energy cannot become available to the cell by simple hydrolytic cleavage of the phosphate bonds of ATP: in this case, it is wasted, released in the form of heat. The process must consist of two successive steps, each of which involves an intermediate product, designated here X-P (in the above equations, X and Y mean two different organic substances; P - phosphate; ADP - adenosine diphosphate).

The term “metabolism” has entered everyday life since doctors began to associate overweight or underweight with excessive nervousness or, conversely, lethargy of the patient with increased or decreased metabolism. To judge the intensity of metabolism, a “basal metabolic rate” test is performed. Basal metabolic rate is a measure of the body's ability to produce energy. The test is performed on an empty stomach at rest; measure the absorption of oxygen (O2) and the release of carbon dioxide (CO2). By comparing these values, they determine how fully the body uses (“burns”) nutrients. The intensity of metabolism is influenced by thyroid hormones, so doctors, when diagnosing diseases associated with metabolic disorders, have recently increasingly measured the level of these hormones in the blood.

Methods for studying metabolism.

When studying the metabolism of any one of the nutrients, all its transformations are traced from the form in which it enters the body to the final products excreted from the body. Such studies use an extremely diverse range of biochemical methods.Use of intact animals or organs. The animal is injected with the test compound, and then its urine and excrement are determined possible products transformations (metabolites) of this substance. More specific information can be obtained by studying the metabolism of a specific organ, such as the liver or brain. In these cases, the substance is administered into the appropriate blood vessel, and metabolites are determined in the blood flowing from this organ.Since this type of procedure is associated with great difficulties, thin sections of organs are often used for research. They are incubated at room temperature or at body temperature in solutions with the addition of the substance whose metabolism is being studied. The cells in such preparations are not damaged, and since the sections are very thin, the substance easily penetrates the cells and easily leaves them. Sometimes difficulties arise due to the substance passing too slowly through cell membranes. In these cases, the tissues are crushed to destroy the membranes, and the cell pulp is incubated with the substance being studied. It was in such experiments that it was shown that all living cells oxidize glucose to CO2 and water and that only liver tissue is capable of synthesizing urea.

Use of cells.

Even cells are very complex organized systems. They have a nucleus, and in the cytoplasm surrounding it there are smaller bodies, the so-called. organelles of various sizes and consistencies. Using appropriate techniques, tissue can be “homogenized” and then subjected to differential centrifugation (separation) to produce preparations containing only mitochondria, only microsomes, or clear liquid– cytoplasm. These drugs can be individually incubated with the compound whose metabolism is being studied, and in this way it is possible to determine which subcellular structures are involved in its successive transformations. There are cases when the initial reaction occurs in the cytoplasm, its product undergoes transformation in microsomes, and the product of this transformation enters into a new reaction in mitochondria. Incubation of the substance under study with living cells or with tissue homogenate usually does not reveal individual stages of its metabolism, and only sequential experiments in which certain subcellular structures are used for incubation make it possible to understand the entire chain of events.

Use of radioactive isotopes.

To study the metabolism of a substance, the following are required: 1) appropriate analytical methods for determining this substance and its metabolites; and 2) methods to distinguish the added substance from the same substance already present in the biological product. These requirements served as the main obstacle to the study of metabolism until radioactive isotopes of elements were discovered, most notably radioactive carbon 14C. With the advent of compounds "labeled" with 14C, as well as instruments for measuring weak radioactivity, these difficulties were overcome. If a 14C-labeled fatty acid is added to a biological preparation, for example, to a suspension of mitochondria, then no special analyzes are required to determine the products of its transformations; To estimate the rate of its use, it is enough to simply measure the radioactivity of successively obtained mitochondrial fractions. The same technique makes it possible to easily distinguish radioactive fatty acid molecules introduced by the experimenter from fatty acid molecules that were already present in the mitochondria at the beginning of the experiment.

Chromatography and electrophoresis.

In addition to the above requirements, methods are also needed that allow the separation of mixtures consisting of small quantities of organic substances. The most important of them is chromatography, which is based on the phenomenon of adsorption. The separation of the components of the mixture is carried out either on paper or by adsorption on a sorbent that is filled into columns (long glass tubes), followed by gradual elution (washing out) of each component.

Separation by electrophoresis depends on the sign and number of charges of the ionized molecules. Electrophoresis is carried out on paper or on some inert (inactive) carrier, such as starch, cellulose or rubber.A highly sensitive and efficient separation method is gas chromatography. It is used in cases where the substances to be separated are in a gaseous state or can be converted into it.

Isolation of enzymes.

The last place in the described series - animal, organ, tissue section, homogenate and fraction of cellular organelles - is occupied by an enzyme capable of catalyzing a certain chemical reaction. Isolation of enzymes in purified form is an important section in the study of metabolism.

The combination of these methods made it possible to trace the main metabolic pathways in most organisms (including humans), to establish exactly where these various processes occur, and find out the successive stages of the main metabolic pathways. To date, thousands of individual biochemical reactions are known, and the enzymes involved in them have been studied.

Since ATP is required for almost any manifestation of cellular vital activity, it is not surprising that the metabolic activity of living cells is aimed primarily at the synthesis of ATP. This purpose is served by various complex sequences of reactions that use the potential chemical energy contained in carbohydrate and fat (lipid) molecules.

METABOLISM OF CARBOHYDRATES AND LIPOIDS

ATP synthesis. Anaerobic metabolism (without oxygen).

The main role of carbohydrates and lipids in cellular metabolism is that their breakdown into simpler compounds ensures the synthesis of ATP. There is no doubt that the same processes occurred in the first, most primitive cells. However, in an atmosphere deprived of oxygen, complete oxidation of carbohydrates and fats to CO2 was impossible. These primitive cells still had mechanisms by which rearrangement of the structure of the glucose molecule ensured the synthesis of small amounts of ATP. We are talking about processes that are called fermentation in microorganisms. The fermentation of glucose to ethyl alcohol and CO2 in yeast has been best studied.

During the 11 sequential reactions required for this transformation to be completed, a series of intermediate products are formed, which are esters of phosphoric acid (phosphates). Their phosphate group is transferred to adenosine diphosphate (ADP) to form ATP. The net ATP yield is 2 molecules of ATP for every molecule of glucose broken down during fermentation. Similar processes occur in all living cells; Since they supply the energy necessary for life, they are sometimes (not entirely correctly) called anaerobic respiration of cells.

In mammals, including humans, this process is called glycolysis and its end product is lactic acid, rather than alcohol and CO2. The entire sequence of glycolysis reactions, with the exception of two last stages, is completely identical to the process occurring in yeast cells.

Aerobic metabolism (using oxygen).

With the advent of oxygen in the atmosphere, the source of which was apparently plant photosynthesis, evolution developed a mechanism that ensures the complete oxidation of glucose to CO2 and water - an aerobic process in which the net ATP yield is 38 ATP molecules for each oxidized glucose molecule. This process of cells consuming oxygen to form energy-rich compounds is known as cellular respiration (aerobic). In contrast to the anaerobic process carried out by cytoplasmic enzymes, oxidative processes take place in mitochondria. In mitochondria, pyruvic acid, an intermediate formed in the anaerobic phase, is oxidized to CO2 in six successive reactions, in each of which a pair of electrons is transferred to a common acceptor, the coenzyme nicotinamide adenine dinucleotide (NAD). This sequence of reactions is called the tricarboxylic acid cycle, citric acid cycle, or Krebs cycle. Each glucose molecule produces 2 molecules pyruvic acid; 12 pairs of electrons are split off from a glucose molecule during its oxidation.

Lipids as a source of energy.

Fatty acid can be used as a source of energy in much the same way as carbohydrates. The oxidation of fatty acids occurs through the sequential elimination of a two-carbon fragment from a fatty acid molecule with the formation of acetyl coenzyme A (acetyl-CoA) and the simultaneous transfer of two pairs of electrons to the electron transport chain. The resulting acetyl-CoA is a normal component of the tricarboxylic acid cycle, and its subsequent fate is no different from the fate of acetyl-CoA supplied carbohydrate metabolism. Thus, the mechanisms of ATP synthesis during the oxidation of both fatty acids and glucose metabolites are almost the same.

If the animal’s body receives energy almost entirely from the oxidation of fatty acids alone, and this happens, for example, during fasting or during diabetes mellitus, then the rate of formation of acetyl-CoA exceeds the rate of its oxidation in the tricarboxylic acid cycle. In this case, the excess acetyl-CoA molecules react with each other, ultimately resulting in the formation of acetoacetic and b-hydroxybutyric acids. Their accumulation is the reason pathological condition, so-called ketosis (a type of acidosis), which in severe diabetes can cause coma and death.

Energy storage.

Animals eat irregularly, and their body needs to somehow store the energy contained in food, the source of which is the carbohydrates and fats absorbed by the animal. Fatty acids can be stored as neutral fats either in the liver or in adipose tissue. Carbohydrates entering large quantities, V gastrointestinal tract are hydrolyzed to glucose or other sugars, which are then converted into the same glucose in the liver. Here, the giant polymer glycogen is synthesized from glucose by attaching glucose residues to each other with the elimination of water molecules (the number of glucose residues in glycogen molecules reaches 30,000). When energy is needed, glycogen is broken down again into glucose in a reaction that produces glucose phosphate. This glucose phosphate is sent to the pathway of glycolysis, a process that is part of the glucose oxidation pathway. In the liver, glucose phosphate can also undergo hydrolysis, and the resulting glucose enters the bloodstream and is delivered by the blood to cells in different parts bodies.

Synthesis of lipids from carbohydrates.

If the amount of carbohydrates absorbed from food at one meal is greater than what can be stored in the form of glycogen, then the excess carbohydrates are converted into fats. The initial sequence of reactions coincides with the usual oxidative pathway, i.e. First, acetyl-CoA is formed from glucose, but then this acetyl-CoA is used in the cell cytoplasm for the synthesis of long-chain fatty acids. The synthesis process can be described as reversing the normal oxidation process of fat cells. The fatty acids are then stored in the form of neutral fats (triglycerides), deposited in different parts of the body. When energy is required, neutral fats undergo hydrolysis and fatty acids enter the blood. Here they are adsorbed by molecules of plasma proteins (albumin and globulins) and then absorbed by cells of various types. Animals do not have mechanisms capable of synthesizing glucose from fatty acids, but plants have such mechanisms.

Lipid metabolism.

Lipids enter the body mainly in the form of triglycerides of fatty acids. In the intestine, under the action of pancreatic enzymes, they undergo hydrolysis, the products of which are absorbed by the cells of the intestinal wall. Here, neutral fats are synthesized from them again, which through lymphatic system enter the blood and are either transported to the liver or deposited in adipose tissue. It was already indicated above that fatty acids can also be synthesized anew from carbohydrate precursors. It should be noted that although mammalian cells can incorporate one double bond into long-chain fatty acid molecules (between C–9 and C–10), these cells are unable to incorporate a second and third double bond. Since fatty acids with two and three double bonds play an important role in mammalian metabolism, they are essentially vitamins. Therefore, linoleic (C18:2) and linolenic (C18:3) acids are called essential fatty acids. At the same time, in mammalian cells, a fourth double bond can be included in linolenic acid and, by lengthening the carbon chain, can form arachidonic acid(C20:4), also a necessary participant in metabolic processes.

During lipid synthesis, fatty acid residues bound to coenzyme A (acyl-CoA) are transferred to glycerophosphate, an ester of phosphoric acid and glycerol. As a result, phosphatidic acid is formed - a compound in which one hydroxyl group of glycerol is esterified with phosphoric acid, and two groups with fatty acids. When neutral fats are formed, phosphoric acid is removed by hydrolysis and a third fatty acid takes its place by reaction with acyl-CoA. Coenzyme A is formed from pantothenic acid (one of the vitamins). Its molecule contains a sulfhydryl (–SH) group that can react with acids to form thioesters. In the formation of phospholipids, phosphatidic acid reacts directly with an activated derivative of one of the nitrogenous bases, such as choline, ethanolamine or serine.

With the exception of vitamin D, all steroids (complex alcohol derivatives) found in animals are easily synthesized by the body itself. These include cholesterol (cholesterol), bile acids, male and female sex hormones, and adrenal hormones. In each case, the starting material for the synthesis is acetyl-CoA: the carbon skeleton of the synthesized compound is built from acetyl groups through repeated condensation.

PROTEIN METABOLISM

Synthesis of amino acids. Plants and most microorganisms can live and grow in an environment in which only minerals, carbon dioxide and water are available for their nutrition. This means that these organisms synthesize all the organic substances found in them themselves. Proteins, found in all living cells, are made up of 21 types of amino acids connected in different sequences. Amino acids are synthesized by living organisms. In each case, a series of chemical reactions leads to the formation of an a-keto acid. One such a-keto acid, namely a-ketoglutaric acid (a common component of the tricarboxylic acid cycle), is involved in nitrogen fixation.

The glutamic acid nitrogen can then be transferred to any of the other a-keto acids to form the corresponding amino acid.

The human body and most other animals have retained the ability to synthesize all amino acids with the exception of nine so-called amino acids. essential amino acids. Since the keto acids corresponding to these nine are not synthesized, essential amino acids must be obtained from the diet.

Protein synthesis.

Amino acids are needed for protein biosynthesis. The biosynthesis process usually occurs in the following way. In the cytoplasm of the cell, each amino acid is “activated” in reaction with ATP, and then attaches to the terminal group of a ribonucleic acid molecule specific for that particular amino acid. This complex molecule binds to a small body, the so-called. ribosome, at a position determined by a longer ribonucleic acid molecule attached to the ribosome. After all these complex molecules are properly lined up, the bonds between the original amino acid and ribonucleic acid are broken and bonds arise between neighboring amino acids - a specific protein is synthesized. The biosynthesis process supplies proteins not only for the growth of the organism or for secretion into the environment. All proteins in living cells undergo breakdown over time into their constituent amino acids, and to maintain life the cells must be synthesized again.

Synthesis of other nitrogen-containing compounds.

In the mammalian body, amino acids are used not only for the biosynthesis of proteins, but also as the starting material for the synthesis of many nitrogen-containing compounds. The amino acid tyrosine is a precursor to the hormones adrenaline and norepinephrine. The simplest amino acid glycine serves as the starting material for the biosynthesis of purines, which are part of nucleic acids, and porphyrins, which are part of cytochromes and hemoglobin. Aspartic acid is a precursor to pyrimidines of nucleic acids. The methyl group of methionine is transferred to a number of other compounds during the biosynthesis of creatine, choline and sarcosine. During the biosynthesis of creatine, the guanidine group of arginine is also transferred from one compound to another. Tryptophan serves as a precursor to nicotinic acid, and a vitamin such as pantothenic acid is synthesized from valine in plants. All these are just individual examples of the use of amino acids in biosynthesis processes.

Nitrogen absorbed by microorganisms and higher plants in the form of ammonium ion, is spent almost entirely on the formation of amino acids, from which many nitrogen-containing compounds of living cells are then synthesized. Neither plants nor microorganisms absorb excess amounts of nitrogen. In contrast, in animals the amount of nitrogen absorbed depends on the proteins contained in the food. All nitrogen that enters the body in the form of amino acids and is not consumed in biosynthesis processes is quickly eliminated from the body in the urine. This happens as follows. In the liver, unused amino acids transfer their nitrogen to a-ketoglutaric acid to form glutamic acid, which is deaminated, releasing ammonia. Further, ammonia nitrogen can either be temporarily stored through the synthesis of glutamine, or immediately used for the synthesis of urea, which occurs in the liver.

Glutamine has another role. It can undergo hydrolysis in the kidneys, releasing ammonia, which enters the urine in exchange for sodium ions. This process is extremely important as a means of maintaining acid-base balance in the animal’s body. Almost all ammonia, coming from amino acids and possibly from other sources, is converted into urea in the liver, so that there is usually almost no free ammonia in the blood. However, under some conditions, urine contains quite significant amounts of ammonia. This ammonia is formed in the kidneys from glutamine and passes into the urine in exchange for sodium ions, which are thus readsorbed and retained in the body. This process intensifies with the development of acidosis, a condition in which the body needs additional amounts of sodium cations to bind excess bicarbonate ions in the blood.

Excess amounts of pyrimidines are also broken down in the liver through a series of reactions that release ammonia. As for purines, their excess undergoes oxidation to form uric acid, which is excreted in the urine in humans and other primates, but not in other mammals. Birds do not have a mechanism for the synthesis of urea, and it is uric acid, and not urea, that is the final product of the metabolism of all nitrogen-containing compounds.

GENERAL VIEWS ABOUT METABOLISM OF ORGANIC SUBSTANCES

It is possible to formulate some general concepts, or “rules,” regarding metabolism. The following few main “rules” allow you to better understand how metabolism occurs and is regulated.

1. Metabolic pathways are irreversible. Decay never follows a path that would be a simple reversal of fusion reactions. It involves other enzymes and other intermediates. Often oppositely directed processes occur in different compartments of the cell. Thus, fatty acids are synthesized in the cytoplasm with the participation of one set of enzymes, and oxidized in mitochondria with the participation of a completely different set.

2. There are enough enzymes in living cells so that all known metabolic reactions can occur much faster than is usually observed in the body. Consequently, there are some regulatory mechanisms in cells. Open different types such mechanisms.

a) The factor limiting the rate of metabolic transformations of a given substance may be the entry of this substance into the cell; It is precisely this process that regulation is aimed at in this case. The role of insulin, for example, is due to the fact that it apparently facilitates the penetration of glucose into all cells, and glucose undergoes transformations at the rate at which it enters. Similarly, the passage of iron and calcium from the intestine into the blood depends on processes whose speed is regulated.

b) Substances cannot always move freely from one cellular compartment to another; There is evidence that intracellular transport is regulated by certain steroid hormones.

c) Two types of “negative” servomechanisms have been identified feedback».

Examples have been found in bacteria that the presence of a product of a sequence of reactions, such as an amino acid, inhibits the biosynthesis of one of the enzymes necessary for the formation of this amino acid.

In each case, the enzyme whose biosynthesis was affected was responsible for the first “determining” step (reaction 4 in the diagram) of the metabolic pathway leading to the synthesis of that amino acid.

The second mechanism is well studied in mammals. This is a simple inhibition by the end product (in our case, an amino acid) of the enzyme responsible for the first “determining” stage of the metabolic pathway.

Another type of feedback regulation operates in cases where the oxidation of intermediate products of the tricarboxylic acid cycle is associated with the formation of ATP from ADP and phosphate in the process of oxidative phosphorylation. If the entire supply of phosphate and (or) ADP in the cell has already been exhausted, then oxidation stops and can resume only after this supply becomes sufficient again. Thus, oxidation, the purpose of which is to supply useful energy in the form of ATP, occurs only when ATP synthesis is possible.

3. Biosynthetic processes involve a relatively small number of building blocks, each of which is used for the synthesis of many compounds. Among them are acetyl coenzyme A, glycerophosphate, glycine, carbamyl phosphate, which supplies the carbamyl (H2N–CO–) group, derivatives folic acid, serving as a source of hydroxymethyl and formyl groups, S-adenosylmethionine - a source of methyl groups, glutamic and aspartic acids, supplying amino groups, and finally, glutamine - a source of amide groups. From this relatively small number of components all the various compounds that we find in living organisms are built.

4. Simple organic compounds rarely participate directly in metabolic reactions. Typically they must first be "activated" by attaching to one of a number of compounds that are universally used in metabolism. Glucose, for example, can undergo oxidation only after it is esterified with phosphoric acid; for its other transformations, it must be esterified with uridine diphosphate. Fatty acids cannot be involved in metabolic transformations before they form esters with coenzyme A. Each of these activators is either related to one of the nucleotides that make up the ribonucleic acid, or is formed from some vitamin. It is easy to understand in this regard why vitamins are required in such small quantities. They are spent on the formation of “coenzymes”, and each coenzyme molecule is used many times throughout the life of the body, in contrast to basic nutrients (for example, glucose), each molecule of which is used only once.

In conclusion, the term "metabolism", which previously meant nothing more complex than simply the use of carbohydrates and fats in the body, is now used to refer to thousands of enzymatic reactions, the entirety of which can be represented as a huge network of metabolic pathways that intersect many times ( due to the presence of common intermediate products) and controlled by very fine regulatory mechanisms.