Catabolism breaks down molecules to release energy, while anabolism uses energy to build molecules. The three macronutrients that yield energy are carbohydrates, fats, and proteins. Carbohydrates have a limited storage capacity, fats have an unlimited storage capacity, and proteins are used for building with no storage capacity. Metabolic pathways are integrated as glucose, fatty acids, and amino acids are broken down into the common intermediate acetyl-CoA, then further oxidized, with degradation and synthesis usually compartmentalized. Glycolysis and the TCA cycle generate ATP through oxidation reactions regulated by key enzymes.

1. Bioenergetics

2. classification
■ Metabolism is divided into two
– a. Catabolism:
– b. Anabolism:
Macronutrients
These are organic compounds that yield Energy through various
metabolic mechanism
They are classified as:
- Carbohydrates (limited capacity for store)
- Fats/Lipids (Unlimited capacity for store)
- Proteins (used for building and No capacity for store)

3. Integration
Connection of Pathways
ATP is generated by oxidation of glucose, fatty acids, and amino acids to yield a common intermediate ‐> Acetyl CoA
Synthesis and degradation pathways almost always separated ‐> Compartmentation

4. metabolism

5. Significance of metabolism

6. GLYCOLYSIS
Regulation:
Step 1,hexokinase
Step 3, phosphofructokinase
Step10, pyruvate kinase

7. Oxidation of Pyruvate
E1= pyruvate dehydrogenase, E2 = dihydrolipoyl transacetylase, E3 =
dihydrolipoyl dehydrogenase

8. TCA cycle

9. Importance of TCA cycle