1. 9.1 Why we need to Eat Pages 396-399

2. Meals 3 per day plus snacks provide us with Materials Energy

3. Nutrients Chemicals required for Growth Tissue Repair Energy

4. Examples Carbohydrates Lipids Protein Water Minerals Vitamins

5. Energy Plants use sunlight to fix CO 2 into sugar. Animals consume plant and animal tissues Cells convert chemical energy in food to ATP energy which fuels cellular processes. All energy eventually becomes thermal energy

6. Size? Small mammals eat 80% of their body weight every day. Large mammals eat 5% of their body weight Ectotherms eat far less frequently

7. Metabolism Anabolism building more complex molecules Catabolism breaks down complex molecules

8. Metabolic Rate Body size Physical activity Sex Age Heredity

9. Measuring Energy Kilojoules, kJ calorie-energy required to raise temperature of 1 g of water by 1 o C. Calorie (1000 calories/ 4180 Joules)

10. Basal metabolic rate (BMR) resting metabolic rate Height, weight, age, sex