Protein

Very ionformative and easy to uderstand powerpoint to bsc 1st yr students.

1. Presented by Preeti shukla Lecturer, RCN, Kanpur

2. Introduction Protein are large, complex, organic compounds made up of carbon, hydrogen, oxygen and nitrogen. The basic units of proteins are the amino acids. Each amino acid contains an acidic an acidic group and an amino group. Proteins consist of chains of amino acids that are linked to each other by a peptide linkage.

3. Amino acids Proteins are made up of small units called amino acids. Some 24 amino acids are stated to be needed by human body of which 9 are called essential amino acids because our body can not synthesize them in required amounts. So they must be obtained from dietary proteins.

4. + Classification of proteins- 1- On the basis of their structure 2- On the basis if their quality Classification by structure- 1- Simple proteins- these proteins are made up of amino acids only, e.g - zein in corn, albumin in egg white and globulin in hemoglobin, etc. 2- Conjugated proteins- these are the proteins which are combined with a non protein molecules. E.g - hemoglobin ( protein + hem), mucin (protein + carbohydrate) and lipoprotein (protein + lipid)

5. 3- Derived proteins- these are produced by the actions of acids, alkalies , heat and enzymes on native proteins, e.g - Peptones and polypeptides are formed when digestive enzymes begin their action on proteins. Classification by quality- 1- Complete proteins or first class proteins- these proteins contain all essential amino acids in sufficient proportion and amounts to meet the body’s need. they are found in animal foods. This protein also called biological complete protein. Ex- Eggs, milk, fish and poultry are complete protein foods.

6. Partially complete proteins or second class proteins- they do not contain all the essential amino acids in required amount. They are capable of maintaining life but cannot promote growth. They are found in plant food. Cereals, pulses, nuts and oil seeds are partially complete proteins foods. Cereals contain inadequate amounts of essential amino acid lysine and pulses are deficient in methionine. Incomplete proteins- they are deficient in a lot of amino acids and are incapable for growth and repair of body cells. They maintain life. One or more essential amino acids may be completely lacking.

7. Function of protein Important functions of proteins are as follows: 1 . Growth and Maintenance- Under normal circumstances, your body breaks down the same amount of protein that it uses to build and repair tissues. Other times, it breaks down more protein than it can create, thus increasing your body’s needs. This typically happens in periods of illness, during pregnancy and while breastfeeding 

8. 2. Causes Biochemical Reactions Enzymes are proteins that aid the thousands of biochemical reactions that take place within and outside of your cells. The structure of enzymes allows them to combine with other molecules inside the cell called substrates, which catalyze reactions that are essential to your metabolism. Enzymes may also function outside the cell, such as digestive enzymes like lactase and sucrose , which help digest sugar. Some enzymes require other molecules, such as vitamins or minerals, for a reaction to take place.

9. Bodily functions that depend on enzymes include (9Trusted Source): Digestion Energy production Blood clotting Muscle contraction Lack or improper function of these enzymes can result in disease

10. 3- Acts as a Messenger Some proteins are hormones, which are chemical messengers that aid communication between your cells, tissues and organs. They’re made and secreted by endocrine tissues or glands and then transported in your blood to their target tissues or organs where they bind to protein receptors on the cell surface. Hormones can be grouped into three main categories : Protein and peptides:  These are made from chains of amino acids, ranging from a few to several hundred.

11. Steroids:  These are made from the fat cholesterol. The sex hormones, testosterone and estrogen, are steroid-based. Amines:  These are made from the individual amino acids tryptophan or tyrosine, which help make hormones related to sleep and metabolism.

12. 4 . Provides Structure Some proteins are fibrous and provide cells and tissues with stiffness and rigidity. These proteins include keratin, collagen and elastin, which help form the connective framework of certain structures in your body. Keratin is a structural protein that is found in your skin, hair and nails.

13. Collagen is the most abundant protein in your body and is the structural protein of your bones, tendons, ligaments and skin . Elastin is several hundred times more flexible than collagen. Its high elasticity allows many tissues in your body to return to their original shape after stretching or contracting, such as your uterus, lungs and arteries.

14. 5- Maintains Proper pH Protein plays a vital role in regulating the concentrations of acids and bases in your blood and other bodily fluids. The balance between acids and bases is measured using the pH scale. It ranges from 0 to 14, with 0 being the most acidic, 7 neutral and 14 the most alkaline.

15. Examples of the pH value of common substances include : pH 2:  Stomach acid pH 4:  Tomato juice pH 5:  Black coffee pH 7.4:  Human blood pH 10:  Milk of magnesia pH 12:  Soapy water

16. 6- Balances Fluids Proteins regulate body processes to maintain fluid balance. Albumin and globulin are proteins in your blood that help maintain your body’s fluid balance by attracting and retaining water . If you don’t eat enough protein, your levels of albumin and globulin eventually decrease.

17. As the fluid continues to build up in the spaces between your cells, swelling or edema occurs, particularly in the stomach region .

18. This is a form of severe protein malnutrition called kwashiorkor that develops when a person is consuming enough calories but does not consume enough protein. Kwashiorkor is rare in developed regions of the world and occurs more often in areas of starvation.

19. 7- Boosters Immune Health Proteins help form immunoglobulins , or antibodies, to fight infection. Antibodies are proteins in your blood that help protect your body from harmful invaders like bacteria and viruses. 8- Transports and Stores Nutrients Transport proteins carry substances throughout your bloodstream — into cells, out of cells or within cells. The substances transported by these proteins include nutrients like vitamins or minerals, blood sugar, cholesterol and oxygen.

20. 9- Provides Energy Proteins can supply your body with energy. Protein contains four calories per gram, the same amount of energy that carbs provide. Fats supply the most energy, at nine calories per gram.

21. Digestion and absorption -the digestion of protein takes place in the stomach and intestine. The proteolytic enzyme present in gastric juice is called pepsin. It acts on proteins in an acid medium and hydrolysis them to simpler compounds known as polypeptides. In the intestine, proteolytic enzyme (trypsin, chymotrypsin and peptidases) present in the pancreatic and intestinal juices hydrolyze the polypeptides to free amino acids . The amino acids are absorbed in the small intestine and enter the blood circulation through the portal vein. Blood carries them to all parts of body.

22. Protein metabolism The chief use of protein is to provide material for body building. Protein can also be used as body fuel. Excess protein and unsuitable protein are split up in the liver to form body fuel in the form of glucose and secondly urea or nitrogenous waste matter. This process is known as the deamination of the amino acids. The nitrrogenous content of the amino acid is converted first in to the ammonia which for the most part combines with carbonic acid splits up into urea water in the liver.

23. The glucose is either burnt or stored as required. The urea is readily soluble and being useless for fuel is carried away by the bloodstream and excreted by the kideny . The waste products of protein metabolism are urea, uric acid and creatinine .

24. Effects of deficiency and excess of proteins A reduced protein intake over a prolonged period of time leads to loss of weight, anemia, nutritional edema, lowered resistance to infection and poor healing of wounds. Protein deficiency is more marked during periods when protein needs are more, e.g - during infancy, childhood, pregnancy and lactation.

25. Protein energy malnutrition or protein calorie malnutrition is common in pre school children in developing countries like india .

26. Protein energy malnutrition (PEM)- PEM has its two clinical forms, kwashiorkor and marasmus. There are two different clinical picture at opposite poles of a single continuum. Nutritional marasmus- this disease was first reported in 1935 in A frica by Dr. Cicely W illiams. This is caused by deficiency of proteins only in diet. Important signs and symptoms are growth failure, edema, diarrhea, anemia and changes in skin and hair.

27. Kwashiorkor- this is caused by severe deficiency of proteins and calories in diet. This disease is characterized by growth failure, loss of fat, signs of dehydration and mental changes, etc.

28. Classification of PEM- protein energy malnutrition is a spectrum of conditions ranging from growth failure to kwashiorkor or overt marasmus. 1- G omez’s classification- it is based on weight retardation. It locate the child on the basis of his/ her weight in comparison with a normal child of the same age . Weight of age(%)= weight of the child/weight of a normal child of same age x 100

29. Weight (kg)= (age in month + 9)/2 – for 1-5 year children. Weight (kg)= 2 x (age in years + 5) - for 5-14 year children.

30. Degree of PEM are calculated as follows:- Weight between 9.0-110 %= normal nutritional status. Between 75-89 % = 1 st degree (mild) malnutrition Between 60 and 74%= 2 nd degree (moderate) malnutrition. Below 60 %= 3 rd degree (severe) malnutrition.

31. Other indicators for assessing under nutrition- Malnutrition with retarded growth in which a drop in the height/age ratio points to a chronic condition of shortness of stunting. Malnutrition with a low weight for a normal height in which the weight for height ratio is indicative of an acute condition of rapid weight loss or wasting.

32. (A) Weight / height (%)= weight of the child/ weight of a normal child of same age x 100 (B) Height / age (%) = height of the child / height of a normal child of same age x 100

33. Arm circumference- it is a reliable estimation of the body’s muscle mass but it cannot be used before the age of one year. Arm circumference exceeding 13.5 cm is a sign of satisfactory nutritional status, between 12.5 to 13.5 cm indicates mild- moderate malnutrition and below 12.5 cm severe malnutrition.

34. Preventive measures- there is simple solution to the problem of PEM. Many types of actions are necessary. 1- health promotion- measures are directed to pregnant and lactating women ( education and nutritional supplements) P romotion for breast feeding. D evelopment of low cost weaning food. I mprovement of family diet. N utrition education H ome economics F amily planning and spacing of birth.

35. 2- Specific protection- Diet of the child must contain protein and energy rich foods such as milk, eggs, fresh fruits. Immunization against diseases. Food fortification. Early detection and treatment. 3- Rehabilitation- Nutritional rehabilitation services this includes to prepare nutritious LADDUS or mixture with following method.

36. Whole wheat= 40 g Bengal grams= 16 g Groundnut= 10 g Jaggery = 20 g Total= 86 g One laddu will provide 33 kcal and 11.3 g protein. Give one laddu daily for few weeks and months. Hospital treatment in case of severe PEM. Follow up care

37. Effects of excessive intake of proteins- An excessive intake of protein is used as energy or converted to fat and store in adipose tissue in body. Excessive intake of protein increase the burden on liver and kidneys to metabolize and excrete the wastes. If these organs are diseased, toxic wastes tend to accumulate in the body. A high intake of protein increases the loss of calcium through urine . Animal proteins such as meat, poultry and whole milk products form a substantial part of the high protein diet.