Nutrients (part 2): Fats & Proteins

1. Fats Fats Fats

2. Question: Do sumo wrestlers eat fat to gain mass?

3. Lesson objectives: • Function of fats • Structure of fats • Occurrence of fats • Saturated vs unsaturated fats • Do sumo wrestlers eat fat to gain mass?

4. Activity: • In pairs, list the possible functions of fats in animals

5. Function of fats Fats serve as: 1. An efficient source & storage of energy 2. As an insulating material (beneath the skin to prevent excessive heat loss) e.g. blubber in whales 3. As a solvent for fat-soluble vitamins, sex hormones & related hormones 4. As a constituent of protoplasm (esp. in protoplasmic mb) 5. As a means to restrict water loss from skin surface → oily secretion by sebaceous glands in skin forms thin layer over surface ; reduces rate of water evaporation & heat loss

6. Fats • Energy-providing foods • Commonly used as food stores (esp. animals) • Consists of elements → carbon, hydrogen, oxygen [less O:H than carbohydrates]

7. Fats • Split by hydrolysis into simpler compounds

8. Occurrence • Food rich in fats e.g. butter, cheese, fatty meat, nuts, leguminous plants • Liver of fish e.g. sharks • Fish like herring fish, salmon (oily fish) • Humans & other mammals can manufacture own fat requirements (not essential in diet)

9. Saturated vs unsaturated fats Saturated fats: • Cholesterol (fatty substance) found together with saturated fats • Deposition of cholesterol in arteries → heart attack Unsaturated fats: • Vegetable oil • Do not cause heart diseases (should be used as substitutes for animal fats)

10. Question: Do sumo wrestlers eat fat to gain mass? No!

11. Sumo wrestlers fatten up on chankonabe • caloric staple of the sumo diet of sumo • consider chanko a nutritious food that helps make your bones denser • Ingredients: tofu, carrots, cabbages, leeks, potatoes, lotus roots, daikon radishes, shiitake mushrooms, and giant burdock into a boiling chicken broth • form their MoonPie-shaped sumo bodies by swilling prodigious portions, along with rice, beer, and an occasional side dish of omelets, shrimp dumplings, and fried chicken. Then they take a long nap

12. Proteins Proteins Proteins

13. Lesson objectives: • Structure of proteins • Function of proteins • Protein deficiency

14. Proteins • Contains carbon, hydrogen, oxygen and nitrogen (often sulphur & phosphorus present) • Molecules largest & most complex • Basic units = amino acids (a.a) • a.a. possess an amino grp.(-NH2) + acidic grp (-COOH) + a hydrocarbon side chain (R)

15. Structure of proteins

16. Amino acids

17. Proteins • 22 naturally occurring a.a. in plant & animal proteins • a.a. link with each other to form long chains • If ≥ 3 a.a link up by peptide bonds = polypeptide/peptone

18. Proteins • Protein molecules made of one or more polypeptide chains • Chains are coiled up to give a distinctive 3D shape • Coils are held in place by weak cross- links (H bonds) → broken easily by heat, acids & alkalis → denaturation

19. Functions of proteins 1. Essential for protoplasm synthesis 2. Used for enzyme & hormone synthesis 3. Used for antibodies formation to combat disease 4. Source of energy

20. Protein deficiency Average adult requires 50- 100g of proteins a day Deficiency → kwashiorkor Symptoms: swollen abdomen (children) 2. Cracked scaly skin • • • 1.