PROTEIN

1. PROTEIN

2. Somatic Protein: Function • Cellular growth, maintenance. • Hormones • Acid base regulation • Water regulation • Enzymes • Transporters • Antibodies • Neurotransmitters

4. Dietary Protein: Function • Use only for the previous functions • Energy. Protein is used for energy when • Glycogen and fat stores are low (starvation). • Rigorous, continuous exercise (ultramarathon). • When carbohydrate intake is inadequate. • When caloric intake is inadequate. • Your body uses protein as energy as a LAST resort to give your brain glucose.

5. Dietary Protein Requirements • For inactive individuals, RDA is .8g / kg • For moderately active individuals 1g / kg • For very active individuals (training athletes) the requirement is 1.2 - 2g / kg depending on type of exercise. • Protein should comprise approximately 10-35% of daily kcal intake. This is about 50-175g for the average person.

7. You want to increase your protein intake to 15% of your total kcal. If you are consuming 2000 kcal, how many grams of protein a day would you need to achieve your 15% goal? Looking on page 193 of your text, determine what foods you could select to would provide the total number of grams you needed in one day.

8. Amino Acids • Amino acids. Are the building blocks of a protein. • Types • Essential. Cannot be made by the body. Must be consumed in food products (plant and animal). • Non-essential. Can be made by the body from other amino acids, or fats, carbohydrate and Nitrogen

9. Essential Amino Acids • Tryptophan • Valine • Threonine • Isoleucine • Leucine • Lysine • Phenylalanine • Methionine • Histidine

10. Chemical Structure of an Amino Acid

11. How Amino Acids Compare

12. Protein Synthesis • Proteins are made by condensation of amino acids together.

14. Structure Dictates Function • For a protein to function correctly all following criteria have to be met: • All amino acids have to be present. • Amino acids must be in the correct sequence as dictated by DNA/MRNA instructions. • Protein has to be in the correct structure with other compounds that are necessary. • If all the following criteria is not met, the protein will either not be made, or the protein will not function properly.

15. Human Insulin: Amino Acid Sequence

18. Protein Denaturation • Proteins can be metabolized, destroyed or rendered dysfunctional by denaturing. • Components of denaturing • Heat • PH changes • Extreme pressure • Detergents and caustic solvents (bleach)

19. If you cook an egg is the protein still available? Denaturing DIETARY protein will not affect it’s protein content. Denaturing SOMATIC proteins (fever, altered blood PH) can adversely affect body functions

20. Protein Quality • Complete Protein: Contains all the amino acids in the proportion that humans require. Ex: all meats and dairy products. Soy is close. • Incomplete Protein: Does not contain all essential amino acids. Ex: grains, vegetables, legumes. • Complimentary proteins. Food products which have amino acid profiles that compliment each other.

22. Legumes Legumes Nuts and seeds Vegetables Grains

23. Evaluation of Protein Quality • PDCAAS. Protein Digestibility Corrected Amino Acid Scoring. • PDCAAS are used to evaluate protein quality in many food products. • To attain a score, the protein’s amino acid profile is compared against the amino acid requirements of an egg. • Digestibility (Biological Value) is established by nitrogen retention studies conducted on humans.

24. Protein Turnover • Nitrogen Balance: Nitrogen IN vs Nitrogen OUT • Nitrogen equilibrium: The amount of N going in EQUALS the amount of N going out. Healthy individuals. • Positive nitrogen balance: The amount of N going in is MORE than the amount coming out. Growing children. • Negative nitrogen balance: The amount of N going in is LESS than the amount of N coming out. Ill or starving individuals.

25. Under consumption of protein. • PEM. Protein-Energy Malnutrition • Marasmus. Starvation • Kwashiorkor. Protein malnutrition • Both have similar and very different symptoms (look in text). However, both are harmful and eventually cause death if left untreated. • For the average person, low protein can cause muscle wasting, fatigue, poor injury recovery, edema, and compromise the immune system.

27. Over consumption of protein • Human body can handle 350 grams or more of protein without harmful effects as long as the nitrogen is being used. • If nitrogen is not being used: • Increased urination to rid excess nitrogen • Increased kidney and liver work load • Excess excretion of nitrogen may affect bone calcium. • Increased urination can lead to dehydration • Use of single amino acids is not advised.

28. Vegetarianism • Chosen for religious, ethical, aesthetic, or experimental reasons. • Three types: • Ovo-Lactovegetarian: Will eat eggs and dairy • Lactovegetarian: Will eat dairy products only • Vegan: Will NOT eat ANY animal derived products. • “Semi-Vegetarians” are NOT true vegetarians • Vegans must use mutual supplementation or soybean products to fulfill protein needs. • Vegans must take D and B12 supplements or received them from fortified foods. • Vegans must be mindful to eat a varied diet to receive calcium, iron, and zinc.

29. Protein Quiz 1. Element found in protein, but not in carbohydrate or fat. a. Carbon b. Hydrogen c. Nitrogen d. Oxygen 2. The building blocks of protein a. Keto acids b. Amino acids c. Ammonia d. glyercol 3. The unraveling of a protein’s structure due to heat, acid, alkalinity or pressure. a. Denaturation b. Condensation c. Trans-amination 4. Incomplete proteins that complete each others amino acid profiles. a. mutual b. essential c. complimentary d. PDCAAS • During construction of a specific protein, the body will replace a missing amino acid with another that is readily available True or False? • Extra Credit: Identify 1 essential amino acid.