Human Biochemistry B.5-9

1. Human Biochemistry B.5-9

2. nutrients • Food required in the diet • Recommended daily intake • Micro less than 0.005% of body mass mg or μg per day • Vitamins and minerals • Needed to produce enzymes or other substances needed for health

3. Macronutrients • For energy and structure • Proteins, carbohydrates, lipids • Na,Mg,K,Ca,P,S and Cl

4. Dietary minerals • Major minerals–in bone Calcium, phosphate, magnesium • Major minerals–in electrolytes Sodium, potassium, chloride • Minor minerals–in metalloproteins Iron, copper, manganese, iodine, cobalt, molybdenum, selenium, chromium, fluoride, zinc • Trace minerals Nickel, silicon, vanadium, tin

5. Electrolyte results • TestPatient's ResultsRef. RangeUnits • BMP • Na L124 136-145mEq/L • K H5.8 3.5-5.1mEq/L • CO2 25 23-29mEq/L • Cl 101 98-107mEq/L • Glucose H107 74-100mg/dL • Ca 10.1 8.6-10.2mg/dL • BUN 17 8-23mg/dL • Creatinine0.9 0.8-1.3mg/dL • Key: L=Abnormal Low, H=Abnormal High, WNL=Within Normal Limits, *=critical value

6. Vitamins • Needed but not synthesized in the body • Water or fat soluble • Water -filtered out by kidneys and excreted • Fat -absorbed and stored in fat tissues • Look at table 21 of the IB data booklet

7. ADEK fat all others water

8. Look at data booklet • Vitamin A (retinol)structure • Fat • Important for vision at low light intensity

9. Look at vitamin C (ascorbic acid) • Water • Cofactor in enzyme reactions • Tissue regeneration after injury

10. D (calciferol) • Fat • Similar in structure to cholesterol • Uptake of Ca+2 by cells • Healthy bones and teeth • Get by sunlight or put in milk

11. Deficiency diseases • Pick one for a report (in pairs) • Vitamin A, Iodine, iron, niacin, thiamin, vit. C, D, selenium, protein • Describe disease, pictures?, reasons, solutions

12. General summary of nutrient problems • What is the problem in the USA? • Worldwide causes and solutions • do questions 9 and 10

13. B.6 Hormones • Communication systems • Nervous – electrochemical = quick • Endocrine – chemical messengers= slower • Different types of molecules • Produced in glands (no ducts) • Receptors are target cells

14. Hormones

16. Another report • ADH, thyroxine, aldosterone, adrenaline, insulin, estrogen, progesterone, testosterone • Gland, type of molecule, target cells, functions

17. Look at your data booklet on hormones • Compare cholesterol, estradiol(estrogen), progesterone, testosterone • Alike and differences

18. Oral contraceptives • Prevents ovulation • Mixture of progesterone and estrogen • Prevent release of follicle stimulating and luteinizing hormones • No ovulation, simulates pregnancy

19. Use and abuse of steroids • Hormone replacement therapy at menopause • Male steroids (anabolic) androgens like testosterone • Enhance male characteristics • Overuse aggressive, liver cancer

22. Do questions 11 and 12

23. B.7 Enzymes • Control system of the body • Biological catalysts

24. structure • Globular proteins-several hundred amino acids • Tertiary and quaternary structures important • Co-factors binding non-protein molecules • Organic called coenzymes inorganic metal ions • Examples vitamins

25. Catalytic action • Define enzyme • Reactant is a substrate • Enzyme substrate complex • Active site on the enzyme is a pocket or groove on the surface • Enzyme is larger than substrate

28. Animation • Another animation

29. saturation • 3 things this tells us

30. Low conc. Rate relates to substate • As conc. Increases enzyme gets tied up • High conc. Rate constant

31. Michaelis-Menten Equation • Vmax turnover number • # molecules/second

32. Michaelis constant Km • ½ Vmax • Specific pH and temp. • Units of concentration • Low Km quick reaction constant rate

33. Enzyme activity • Temperature • Increase rate as temp goes up • At a point the protein denatures

34. Human optimum tends to be 37 oC • Denaturation usually is irreversible • Lowering temperature only causes deactivation • High fevers can be fatal

35. pH • Changes affect the equilibrium positions • If it affects the R groups in amino acids it will alter the attractive ability thus influences the shape • Each enzyme has an optimal pH • Extremes cause denaturation

36. For humans 7.4

37. Heavy metal ions • Lead, copper, mercury and silver • Poisonous • React with SH groups on cysteine to make S-metal • Changes shape

38. Chemical inhibitors • Competitively at the active site • Non-competitively at another area

39. Competitive inhibitors

40. Takes a higher substrate concentration to reach Vmax

42. Chymotrpsin is an enzyme which hydrolyzes peptides at the carbonyl side of tyr or phe or trp (i.e. those that have an aromatic side chain. In the graphic on the left, the substrate and the irreversible inhibitor are shown in the active site pocket. In the case of the inhibitor the reaction starts in the same way as with the substrate, but the end result is that the inhibitor is covalently bonded to the histidine-57 in the active site and is not reversible

43. Changes shape of enzyme • Increasing concentration doesn’t help • Poisons DDT, cyanide and antibiotics • Means of controlling metabolic activity in healthy cells • Thermostat and heater

44. Enzymes vs. catalysts • Enzymes are • Specific • Reaction saturation • Speed up 1000 to 1000000 times • Can be inhibited • Very sensitive to environmental changes

45. Do questions 13 and 14

46. B.8 Nucleic acids • DNA and RNA • Information storage of genetics in the nucleus • How did it begin?

50. DNA must be stable • Contain a code • Be able to replicate