AP Biology - ETC and Fermentation

Where is the ETC for aerobic cellular respiration?

In/on the cristae

Oxidative Phosphorylation

What is another name for the ETC?

Is oxidative phosphorylation different from substrate-level phosphorylation in glycolysis and the Krebs Cycle?

YES

What is the difference between oxidative and substrate-level phosphorylation?

Oxidative uses a free-floating phosphate without a carbon backbone, substrate-level uses a phosphate attached to a carbon backbone

How many ATPs does NADH make in the ETC?

THREE

How many ATPs does FADH2 make in the ETC?

TWO

Where does fermentation occur?

in the cytoplasm (cytosol)

When does fermentation occur?

• When the demand for ATP is higher than how much cellular respiration can deliver alone

• When O2 is low (NADH acts as the final oxidative agent and makes NAD+ instead of H2O)

Is fermentation aerobic or anaerobic?

Anaerobic

Why is fermentation better than nothing?

Since the ETC does not occur in anaerobic conditions, NAD+ is created, which can cause glycolysis to occur (still produces 2 ATP instead of the 3 from NADH)

When does lactic acid fermentation occur?

• When the demand for ATPs exceeds the aerobic pathway’s capacity

• Occurs in muscle cells during heavy exertion

What is generated during lactic acid fermentation?

NAD+ and lactic acid (lactate)

What happens to the muscles during lactic acid fermentation?

• lactate causes them to become sore

• Muscles temporarily become anaerobic