Proteins: An In Depth Discussion

1. Proteins: An In Depth Discussion Presented by: Professor Steven Dion – Salem State College Sport, Fitness & Leisure Studies Dept.

2. Proteins • Next to water it’s the most abundant substance in body. • It aids in the transport of iron and oxygen to the body as well as: • aiding in the growth, maintenance and repair or all body tissues • making of enzymes, hormones and antibodies, • helps fight infection. Proteins - Pro. Dion

3. Classification of Proteins / Amino Acids • Peptides - link amino acids together to take on different forms • Dipeptide - 2 joined amino acids • Tripeptide - 3 joined amino acids • Polypeptide - up to 100 amino acids • Protein - combining more that 100 amino acids combined A single cell can contain thousands of different protein molecules. The body has over 50,000 different protein-containing compounds. Proteins - Pro. Dion

4. Other Purposes: • Blood plasma, visceral tissue, and muscle = 3 major sources of body protein. • There is not storage of unused protein - all the protein in the body is being used for something - no true “reservoir.” • Body protein makes up 12 - 15 % if body mass - but the protein content of different cells varies. For example: • The brain cell consists of 10%, a white blood cell and muscle cell have up to 20% protein. • Skeletal muscle makes up about 65% of the bodies protein - but can increase with lifting. Proteins - Pro. Dion

5. Amino Acids • They are the building blocks for synthesizing tissues: (approx. 20-22 amino acids) • AA’s: activate vitamins key role in metabolic and physiologic functions. • Anabolism: tissue building process - accounts for 1/3 of bodies intake of protein per day during rapid growth in infancy and childhood. • As we slow down growing - so does the amount of protein the body sets aside for anabolism. • Once you have reached full growth - there is a continual turnover of protein tissue. • AA’s / proteins make up the collagen which give structure to our hair, teeth, nails, skin, bones, and ligaments. Proteins - Pro. Dion

6. Other Properties & Roles • Globular Proteins: - make up over 2000 enzymes that speed up chemical reactions and regulate the catabolism (break down) of fats, carbs, and proteins for energy release.  • Proteins assist in regulating acid-base quality of the body fluids - • Buffering neutralizes excess acid metabolism formed during vigorous exercise. Proteins - Pro. Dion

7. Amino Acids • The body can not synthesize 8 amino acids (nine in children and some older adults) • Those 8/9 are called essential amino acids: so you need to get them from external nutrients. • The 8 include: isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. • Infants can not synthesize histidine and have difficulty with arginine. Proteins - Pro. Dion

8. Amino Acids • The body manufactures the remaining 9 • Those 9 are called nonessential amino acids. • Nonessential means our body synthesizes them within the body, not that they are not important • The source of the amino acids doesn't matter - just as long as the body gets the AA’s whether it’s from plants or animals. • Ideally coming from a nutrient rich, healthy food source. Proteins - Pro. Dion

9. Proteins Major Categories • Complete proteins or higher quality proteins - come from foods containing all of the essential amino acids in the quantity and correct ratio to maintain nitrogen balance and allow for tissue growth and repair. • Incomplete proteins or lower quality proteins - lack ore or more of the essential amino acid. Incomplete protein diets will eventually lead to protein malnutrition.  Proteins - Pro. Dion

10. Protein Sources • Complete proteins sources include: • eggs, milk, meat, fish, and poultry. (pg. 31 chart – rating scale) • Eggs provide the optimal mixture of essential AA’s. • Ideally choose egg whites and egg white protein shakes over whey/Casine powder shake. • Complementarysources of incomplete / low quality proteins to create a complete protein meal: • You can combine incomplete proteins to create a complete protein meal. • For example: rice and beans, rice and lentils, tortillas and beans, and rice and peas Proteins - Pro. Dion

11. Recommended Dietary Intake: • Anintake greater than 3 times the recommended level does not enhance work capacity during intensive training. (so 12-15% of total cals) • Excessive dietary protein becomes used for energy or recycled as components of other molecules including stored fat in subcutaneous (adipose) deposits. Proteins - Pro. Dion

12. In Addition • Consumption: Consume .83 – 1 gram per kg. • For example: a 90 kg male should consume approximately 75 grams of protein per day. • Infants and growing children should consume 2 – 4 grams per kg. • If you are pregnant: Increase by 20 grams and if you are nursing increase by 10 grams. Proteins - Pro. Dion

13. Protein Metabolism • In well nourished individuals - protein breakdown contributes about 2-5% of the body’s total energy requirements. • Catabolism: protein breakdown • 1. Body breaks nutrients into its amino acid components. • 2. The amino acids go through the liver = deanimation • 3. Deanimation causes AA’s to lose a nitrogen - creating urea (urine) • 4. The new AA is free to produce carbs or fat or metabolize directly for energy. Proteins - Pro. Dion

14. Key Terms • Anabolism – tissue building process • Catabolism – tissue breakdown process • Deanimation – the removal of the amino (nitrogen) from the amino acid – thus creating urea. • The remaining deaminated carbon compound can be used to form carbs or fat to produce energy. • Excessive urea production requires increased fluid loss – because urea must be diluted. Proteins - Pro. Dion

15. Key Terms Continued • Transamination – the passing of nitrogen of an amino group form one compound to another • Positive nitrogen balance – nitrogen (protein) intake exceeds nitrogen excretion. (children, pregnancy & illness) • Negative nitrogen balance – greater nitrogen output compared to intake. Energy has become a fuel source.(heavy exercises, fasting, starvation diets) Proteins - Pro. Dion

16. Cautionary Note • When catabolization occurs, ammonia is a byproduct of the process. This increases the amount of urea produced. • High levels of urea production can lead to dehydration and calcium loss since urea needs to leave the body with water and it needs to be matched with calcium to do so. (Osteo… what?) • There is no advantage of consuming more protein - (except in times of growth and if you have poor / malnourished diet) • These problems have been shown in individuals taking 3 - 4 grams per body wt. Proteins - Pro. Dion

17. Info to Consider • The type or amount of protein or proteins needed depends on your type of activity levels / exercises. • A certain type of protein is made inside the muscle nuclei depending on its use - either aerobic or anaerobic protein synthesis. • Athletes retain more protein and use more protein for energy sources than non-athletes. (pg. 337) Proteins - Pro. Dion

18. Gender and Protein • Naturally men have a higher metabolism than most women because of their larger physical size, bone structure, muscle mass & larger brain size. •  Women who have gone through menopause, may need to pay attention to protein intake and increase calcium to assist in the prevention of osteoporosis - Proteins - Pro. Dion

19. Vegetarianism • Vegan - no animal products • Lacto-vegetarian - eats only dairy products - avoid all flesh products • Ovo-vegetarian – eats only eggs • Ovolacto-vegetarian - eats eggs and dairy • Pesco-vegetarian - eats fish, dairy, eggs, no red meat, poultry & pork • Semi-vegetarians - eat fish chicken, dairy, and eggs, but no red meat & pork Proteins - Pro. Dion

20. Benefits of the Vegetarian Diet • Lowers LDL cholesterol levels without having an effect on HDL levels • Typically less fat and healthier body • Less possible toxins in food • Reduced risk of colon, heart, breast cancer Proteins - Pro. Dion

21. Drawbacks of a Vegetarian Diet • Difficult to have a lot of variety - more difficult to prepare yummy foods dishes • Can be expensive • In the US less education on creative and healthy cooking • Lack of knowledge can lead to deficiencies • Possible deficiencies in B2 (riboflavin) and B12, and D. B2 is found in meats and eggs, dairy - but broccoli, almonds, asparagus • B12 and D are found only in dairy products: but B12 is made by body and D can be synthesized with sunlight, or soy milk. Proteins - Pro. Dion