Pharos university Faculty of Allied Medical SCIENCE Biochemistry 1 (MGBC-101)

1. Pharos universityFaculty of Allied Medical SCIENCEBiochemistry 1(MGBC-101) Dr. Tarek El Sewedy Department of Medical Laboratory Technology Faculty of Allied Medical Sciences

2. Lecture 5 Amino acids and proteins Part 2

3. Intended Learning Outcomes By the end of this lecture, students will learn: Amino Acids classification.

4. Classification of amino acids Amino Acids and proteins nutritional facts Lecture Content

5. Structure of amino acids The basic structure of an amino-acid molecule consists of a carbon atom bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a fourth group that differs from one amino acid to another and often is referred to as the-R group or the side chain. The-R group, which can vary widely, is responsible for the differences in chemical properties.

6. α, β, or γ Amino Acids • Amino acids may be characterized as α, β , or γ depending on the location of the amino group on the carbon chain. • α are on the carbon adjacent to the carboxyl group. • β are on the 2ndcarbon • γ on the 3rdcarbon from the carboxyl group.

7. α− amino acids • Amino acids found in proteins are α− amino acids. • The amino group is always found on the carbon adjacent to the carboxyl group

8. Metabolic Classification of theAmino Acids • Essential and Non-essential • Glucogenicand Ketogenic

9. Essential Amino Acids • Only 11Of the 20 amino acids that make up proteins can be synthesized by the human body • The other 9 amino acids must be acquired from food sources. These amino acids are known as essential amino acids

10. Non essential Amino Acids

11. Glucogenicor ketogenic Amino acids • Glucogenicaminoacids are degradedto compounds that can be used as carbon skeletons for glucose synthesis via gluconeogenesis. • Ketogenic amino acids are degraded to compounds that can only be used to generate the ketonebodies.

12. Glucogenic Amino Acids

13. Ketogenic Amino Acids • Metabolized to acetyl CoA or acetoacetylCoA then to ketone bodies • Leucine • Lysine

14. Amino Acid Functions 1. Amino acids are the building blocks of proteins. 2. Some amino acids and their derivatives function as neurotransmittershormones. 3. It may supply the carbohydrates pool with glucose ?????????.

15. Protein functions • - Catalytic functions [enzymes] • - Receptor [insulin receptor] • - Structural function [collagen] • - Transport [hemoglobin] • - Protective functions [Antibodies]

16. Protein function (cont…) • - Hemostasis [clotting factors] • - Hormonal functions [insulin, glucagon, GH] • - Control of gene expression [transcription factors] • - DNA packing [histones] • - Act as buffers.

17. Protein nutritional facts

19. Spirulina quinoa soybeans Almond

20. Good sources of protein

21. Amino Acid nutrition Our body doesn’t use proteins in a direct way; first proteins are decomposed into amino acids and then amino acids are used for the resynthesize of muscular proteins

22. Protein and diet

23. Protein and diet • An individual's daily protein requirement depends on several factors, including: • Age - a growing child's needs will not be the same as an individual aged 80 years • Sex - males generally require more protein than (non-pregnant or non-breastfeeding) females • Weight - an individual who weighs 100 Kg will require more protein compared to somebody who weighs 50 Kg. • Muscular exertion - an individual who earns his living delivering pianos will require more protein than a computer programmer of the same age and height. • Muscle mass - a muscle-bound weight trainer will need more dietary protein than a marathon runner • Health - a person who is recovering after an illness or medical procedure may need more dietary protein than other people.

24. Percentage of energy that should come from protein: • Children aged 1 to 3 years - 5% to 20% • Children aged 4 to 18 years - 10% to 30% • Adults - 10% to 35% • According to the US Department of Agriculture, our protein intake should be: • Infants - 10 grams per day • Teenage boys - up to 52 grams per day • Teenage girls - up to 46 grams per day • Adult men- approximately 56 grams per day • Adult women - approximately 46 grams per day • Pregnant or lactating (breastfeeding) women - about 71 grams per day

25. Protein deficiency • Mental retardation and reduced IQ. • Growth problems • Wasting and shrinkage of muscle tissue • Apathy • Swollen belly • Anemia • Weaker immune system

26. Protein Excess • Weight gain. • Intestinal irritation. • Risk of heart disease • Kidney problems • Gout disease

27. Students selected for assignment

28. ASSIGNMENTS • Selected students are requested to prepare slides about one of the following topics (To be delivered before next lecture): • Digestion of proteins • Essential amino acids. • Non essential amino acids • Physical properties of amino acids. • Chemical properties of amino acids. • Disease resulting from disturbance in amino acid metabolism. • Ketone bodies and amino acids • Translation of RNA

29. Study Question • Write three points about : Classification of amino acids • 1- • 2- • 3-

30. Suggested readings: • Principles of Biochemistry, Donald J. Voet, Judith G. Voet, Charlotte W. pratt; Willey, 3rded.