FUNCTIONS OF PROTEIN
Proteins perform the following functions in our body.
- The function of body building-Protein is mainly a body-building food element. The presence of protein is followed by the amount of water in the body. For example, protein is mainly present in hair, nails, skin, endocrine glands, muscles, and bones, etc.
Protein is found in all the fluids of the body except bile and urine. It plays an important role in forming new tissues, whereas in infancy, childhood, adolescence, and pregnancy, protein is the main requirement for physical growth and development.
- Work for the reconstruction of the body’s wear and tear-Just as protein helps in the formation of new tissues, in the same way, protein is needed for the repair of the wear and tear caused by the continuous functioning of the body. The wear and tear of cells and tissues in the body can occur during an accident, injury, burn or operation, etc.
- Blood plasma for a clotting-A protein called fibrinogen is found in the blood plasma for clotting of blood. Bleeding occurs due to injury, cut, or accident. If the blood does not clot within 4-5 minutes and the bleeding does not stop, a lot of blood is lost from the body and life can be in danger. Blood clotting is a complex process. In this process, thrombin, which is a protein converts fibrinogen to fibrin. Due to this, the flow of blood stops.
- Regulating the various functions of the body-Protein keeps the amount of acid and base in our body regular and when needed, the protein itself acts like a base or acid, which is called Protein Buffers. It does not allow the acid base of the body to accumulate so that the body’s pH can remain stable.
- Regulating the balance of water in the body- Due to the lack of protein, water starts accumulating in the body, because protein maintains the balance of water content on both sides by controlling the activities inside and outside the cell.
- Protein molecules control the osmotic pressure in our body-osmotic pressure is the pressure that controls osmosis. Osmotic pressure is the pressure exerted by osmosis on the cell membrane of cells. Osmosis is the process in which there is a flow of less concentrated matter present in the cells towards the more concentrated matter, this flow continues until the concentration on both sides becomes equal, due to which the osmotic pressure falls on the cell membrane. Protein molecules regulate it.
- Producing enzymes, hormones, antibodies- Proteins form many enzymes in the body. It forms many nitrogen-containing compounds in the body, by which many chemical reactions are completed:
(a) Manufacture of enzymes—These are made of proteins and proteins form enzymes. Enzymes perform various functions in the body; For example, digestion of food, oxidation, metabolism, etc. Enzymes like pepsin, chymotrypsin amylase, lipase, etc. are produced only in the presence of proteins. Proteins form many nitrogen-rich compounds in the body.
(b) Producing Hormones-Proteins are essential for the manufacture of hormones. Hormones control and regulate various activities. For example, the thyroxine hormone regulates the oxidation process and physical growth, insulin plays a main role in maintaining the level of glucose in the blood. Similarly, the pituitary, adrenaline, sex hormones, etc. perform various functions in the body.
(c) In the formation of antibodies- Antibodies provide the body’s ability to fight against various diseases and help in increasing the immunity of the body. Antibodies are not produced due to a lack of protein in the diet. As a result, the ability of a person to fight diseases decreases. A person suffers from many types of diseases and falls ill again and again. Therefore, it is very important to have protein in the food to lead a healthy life.
- In providing energy- in the absence of carbs and fats, protein also serves to provide energy. One gram of protein provides 4 calories of energy. Whenever there is not enough fat and carbs present in the diet, then only protein provides energy. When protein is used in excess, it accumulates in the body in the form of fat and when these are used to provide energy, body-building, which is the main work, becomes secondary.
- In milk production- The mother’s milk is the first food of a newborn baby. Mother’s milk is the best for the proper nutrition of the baby. Protein is essential for the production of breast milk. Since mother’s milk contains 1.2% protein. Therefore, the lactating mother should consume more amount of protein.
EFFECT OF PROTEIN DEFICIENCY
Protein is very essential for physical growth and development. Protein is the body’s constructive element and makes new cells, fibers, and tissues and repairs damaged cells and fibers that are broken. A deficiency of protein leads to anemia, marasmus, kwashiorkor, diarrhea, bloating, etc. The liver does not perform its function properly in the absence of protein.
Most of the victims of protein deficiency are children of 1-5 years. Protein-calorie malnutrition occurs due to a lack of both protein and energy. The following three diseases mainly occur in children due to a deficiency of protein.
- Marasmic Kwashiorkor
- Kwashiorkor-Kwashiorkor was discovered by Sisley William in 1935. It means “the disease that occurs to the first child after the birth of the second child.” The following symptoms are seen in children suffering from Kwashiorkor:
(1) Growth retardation-Both growth and development of the child stop.
(2) Swelling-Swelling (Oedema) occurs due to water filling in the body tissues. First of all, swelling comes to the toes and feet. After this swelling comes on other parts of the body like thighs, hands, and mouth. Due to the accumulation of water in the tissues, there is a decrease in serum albumin in the blood.
(3) Wasting of Muscles—The muscles of the body start getting destroyed. Its effect is more on the muscles of the arms, hands, and legs. The arms, hands, and legs become thin and weak.
(4) Mental changes-Apathy and irritability come in the nature of the child. Children start crying while talking and they do not want to play the child feels sluggish, lethargic, and tired.
(5) Anemia-Due to lack of protein, hemoglobin is not formed. Hence. there is a disease of blood deficiency.
(6) Effect of fat in the liver-Due to the lack of protein, fat deposits on the liver, due to which its size increases. The size of the pancreas becomes smaller.
(7) Effects on the skin-Due to lack of protein, the skin becomes dry and dull. There is a change in the color of the skin. There are dark brown and black marks on the skin.
(8) Effect on hair-Hair becomes dry, rough, and dull. There is a change in the color of the hair. Hair turns gray or white, and hair growth stops.
(9) Loss of Appetite and Diarrhoea-Due to lack of protein, many digestive disturbances arise. Many digestive enzymes are not produced The child doesn’t feel hungry and diarrhea may also occur.
(10) Effects on Mucous Membrane-Mucous membranes are affected due to lack of protein. Due to this, the lips begin to crack and the surface of the tongue becomes greasy.
(11) Moon-shaped Face—In addition to the hands and feet being swollen, the swelling also occurs on the face, due to which the child’s face becomes round like the moon.
(12) Effect on Nervous System-Due to lack of protein, not only the physical development of the child stops, but mental development also stops. The child’s ability to learn decreases. Endocrine hormones are not produced and secreted properly. There is a disturbance in blood circulation.
(13) Vitamin Deficiency–Protein has a role in the formation of some vitamins. Due to the deficiency of B vitamins, there is a burning sensation in the corners of the lips and in the tongue, due to which the whole mouth is not able to open.
- Marasmus—This disease occurs due to a deficiency of both protein and energy. After the age of 6 months, apart from the mother’s milk, other food items are also necessary for the children, but if the children do not get them, there is a deficiency in the nutritional elements. Therefore, this disease usually appears in children up to the age of one year. In this, children are more prone to infectious diseases, especially diarrhea. The following symptoms of this disease are:
(1) Growth stops—Some children have an increased appetite, and some have a low appetite. Due to an increase or decrease in appetite, the growth of the body stops, and the stomach contracts. The weight and height of the child decrease. Dwarfism occurs in the child.
(2) Digestive system is affected-In by this disease, loose watery diarrhea occurs and the stomach becomes bloated.
(3) Inflammation in the body-Swelling occurs in the body due to lack of protein. First, there is swelling in the legs, then there is swelling in the body.
TREATMENT OF KWASHIORKOR AND MARASMUS
Treatment of kwashiorkor and marasmus is possible through food. Food should contain energy and protein elements as well as other nutritious elements. Milk, curd, buttermilk, cheese, meat, fish, eggs, pulses, green leafy vegetables, fruits, cereals, etc. should be included in the diet. In these diseases, the child often does not feel hungry. It is necessary to increase the appetite of the child. Home remedies should be done in the following way:
(1) The child should be given a small amount of fat-free milk.
(2) Ghee, oil, and chili spices should not be used in food. Ripe fruits, porridge, etc. should be given after mashing.
(3) Liquid beverages; For example, vegetable soup, moong dal, fruit juice, lentil water, rice porridge, etc. should be given.
(4) For the supply of vitamins and mineral salts, juices of green leafy vegetables, yellow fruits, oranges, seasonal fruits, etc. should be given.
(5) Various food items to be used; For example, mixing vegetables and grains, khichdi, milk, porridge, and khichdi should be fed mixed with milk or curd.
(6) More caloric foods should be fed to the child in marasmus.
(7) In the event of inflammation, the use of salt should be reduced.
(8) A good type of easily digestible protein should be given.
(9) There should be iron and vitamin-rich food items in the diet.
DAILY REQUIREMENT OF PROTEIN
The demand for protein is high in infants, children, adolescents, and pregnant and lactating mothers. The demand for protein also increases in the elderly. Indian Medical Research Committee (ICMR) in 1933) nutritionists proposed the daily requirement of protein for Indians as follows:
Protein is fulfilled according to the demand of the body for the necessary:
(1) Cereals and pulses should be used together so that they all have essential amino acids.
(2) One part of the essential protein should be taken from animal protein-rich substances and the remaining part from plant-provided substances.
(3) Of the calories we need daily, 50% should be taken from carbs, 80-85% from fat, and 10-15% from protein.
DIGESTION OF PROTEIN
- Digestion in the mouth-Digestion of proteins does not take place in the mouth, digestion begins in the stomach and small intestine.
- Digestion in the stomach-In this, the digestion of proteins takes place in an acidic medium. The food reached here is of an alkaline medium. Here hydrochloric acid (HCL) is the acidic medium. There are two digestive enzymes that digest proteins (i) renin and (ii) pepsin.
(i) Renin reacts to milk in the presence of HCL to convert it into curd.
Milk X (+HCL)/Renin = Curd
(ii) Pepsin reacts on curd and other protein-rich foods to convert them into ideas, pepsinogens, and peptones.
Protein → Polypeptide + Pepsinogen + Peptones
- Digestion in the duodenum-Here an alkaline medium is produced by the bile and the undigested protein is digested by trypsin and chymotrypsin of the chyme juice from the chyme gland.
- Digestion in Small Intestine–The above polypeptide comes to the small intestine, where digestion takes place in an alkaline medium. The Erepsin enzyme converts protein into its simplest form, an amino acid.
Polypeptides → Amino Acids
ABSORPTION OF PROTEIN
Absorption of digested proteins occurs mainly in the small intestine from the alimentary canal. Although the absorption of proteins to some extent also occurs in the stomach and large intestine, 60% of protein is absorbed by the small intestine, 28% is in the large intestine and 11% is in the stomach.
There are many finger-like bulges in the hematopoietic part of the small intestine, which are called villi and they perform the function of absorption of amino acids.
METABOLISM OF PROTEIN
Amino acids are transported to the liver through the blood. Here the amino acid is converted to urea. Some part is synthesized in plasma, the remaining proteins are carried by the blood circulation to various tissues and cells of the body. Body cells and tissues use amino acids in different ways:
(1) Some amino acids are synthesized to build new cells and tissues of the body. These amino acids form new cells.
(2) There is a constant breakdown in the cells of the body. These cells are also repaired and rebuilt by proteins.
(3) Some amino acids, for example, methionine, cysteine, and alanine are converted into glucose, part of which is converted into energy, and the remaining part is stored in the muscles in the form of glycogen.
(4) Some amino acids are used in the synthesis of hormones and enzymes.
(5). Parts of some amino acids such as leucine make fatty acids. Some of these fatty acids are used to provide energy. The remaining part gets stored as fat. (BCom 1st Year Nutrients Macro and Micro-Protein Notes Study Material)
(6) Amino acids that cannot be synthesized in excess of the requirement are converted into nitrogen. This fraction is excreted out of the body through urine in the form of urea. (BCom 1st Year Nutrients Macro and Micro-Protein Notes Study Material)
SIGNIFICANCE OF PROTEIN
- Amount of calories in the diet-If the body gets calories from carbs and fat, then protein remains free for bodybuilding work.
- Digestibility of protein-What will be the digestibility of protein, it depends on how nitrogen is absorbed in the protein.
- The biological value of protein-We gets nitrogen from the protein we take. 6.25 Protein provides 1 gram of nitrogen. The nitrogen that we get from protein, our body excretes out in the form of urine, feces, and sweat.
FACTORS AFFECTING THE PROTEIN’S DEMAND
- Body –The greater the breakdown in the cells, and tissues of the body the more the muscle is damaged. More protein is needed to repair and rebuild these broken damaged cells and tissues.
- Gender-The demand for protein is more in women than in men. Every month women menstruate, due to which a lot of blood comes out of the body. (BCom 1st Year Nutrients Macro and Micro-Protein Notes Study Material)
- Due to Pregnancy and Lactation, the woman needs more protein. During pregnancy, the fetus develops in the mother’s womb. The development of the fetus depends on the diet of the mother. Therefore, a large amount of protein is needed for the development of the fetus growing in the womb. There is an increased protein demand during pregnancy. In a lactating woman, the baby is nourished by the mother’s milk. Therefore, a lactating mother needs more protein than an ordinary woman.
- In the state of fever-There is more breakdown of body cells when there is a fever. Therefore, more protein is needed in the stage of fever or when the fever is cured. Similarly, in case of burns, accidents, and excessive blood loss, the demand for protein increases. (BCom 1st Year Nutrients Macro and Micro-Protein Notes Study Material)
- Age-Physical development is rapid in children. Therefore, they require more protein. The demand for protein increases during infancy, childhood, and adolescence. The demand for protein is high even in old age.
- Protein-Protein is the need of children suffering from energy malnutrition. Similarly, if the protein digestibility in the digestive system is low, the demand for protein also increases.