Cellular Respiration

Question 1

What are the three main pathways of aerobic respiration?

Answer 1

1. Glycolysis
2. The citric acid cycle
3. Electron transport chain

Question 2

What is glycolysis?

Answer 2

Glycolysis is the breakdown of glucose to pyruvate in the cytoplasm, it has two phases.

Question 3

Name the two phases of glycolysis and describe what happens during each.

Answer 3

1. Energy investment phase
   - ATP is produced for the phosphorylation of glucose and intermediates.
2. Energy payoff phase
   - More ATP is produced, there is an overall net gain of ATP.

Question 4

Where does the citric acid cycle occur?

Answer 4

Mitochondrial Matrix

Question 5

What happens during The Citric Acid Cycle?

Answer 5

Pyruvate is broken down to an acetyl group that combines with coenzyme A, forming acetylene coenzyme A. The acetylene group from acetylene coenzyme A then combines with oxaloacetate to form citrate.
Then a series of enzyme controlled steps converts citrate back into oxaloacetate, generating ATP and releasing carbon dioxide.

Question 6

Where does the Electron Transport Chain occur?

Answer 6

Inner mitochondrial membrane

Question 7

What is the Electron Transport Chain?

Answer 7

It is a series of carrier proteins.

Question 8

What happens during the Electron Transport Chain?

Answer 8

Electrons are passed along the electron transport chain releasing energy. This energy allows hydrogen ions to be pumped across the inner mitochondrial membrane. The return flow of these ions back through the membrane proteins ATP synthase results in the production of ATP. The returning hydrogen ions and low energy electrons combine with oxygen to form water.