Cellular Respiration

- Cellular respiration is the most efficient catabolic pathway
- It is a step-wise process (slowly releasing ATP)

There are 3 metabolic stages:
1. Glycolysis (occurs in cytoplasm) (breaks down glucose into 2 molecules of pyruvate)
2. Citric Acid Cycle (occurs in the matrix of mitochondria) (it completes breaking down glucose)
3. Oxidative posphorylation (occurs in the inner membrane of mitochondria)

Glycolysis has 2 major phases: Energy investment phase and Energy payoff phase
Oxygen is not required in either glycolysis or citric acid cycle

- In glycosis, 2 ATP was used, 4 was produced, so the net worth is 2 ATP

- In between glycolysis and citric acid cycle, carbon dioxide was lost (also known as dicarboxylation), so only 2 carbon remain. Coenzyme A joins in to form Acelyle CoA
- for each pyruvate, 1 carbon dioxide was lost, and 1 NADH was formed
- the only difference in transformation of NAD to NADH and FAD to FADH2 is that NAD to NADH uses more energy than FAD to FADH2
- NADH can make 3 molecules of ATP
- FADH2 can only make 2 molecules of ATP

- As each step progresses, 1 proton is lost and the electronegativity increases for each protein.