Week 1: ATP-ADP energy cycle and cellular respiration

Question 1

What is cellular respiration?

Answer 1

The metabolic processes within the body by which the catabolism of food fuels (mostly glucose) produces ATP.

Question 2

What are the 2 main phases of cellular respiration?

Answer 2

• Aerobic metabolism
• Anaerobic metabolism

Question 3

What is aerobic metabolism, and how much ATP does it generate?

Answer 3

In the presence of oxygen, glucose is completely broken down into carbon dioxide and water.

This generates heat and 30-32 ATP molecules.

Question 4

What is anaerobic metabolism, and how much ATP does it generate?

Answer 4

Through a series of reactions which do not require oxygen, glucose is partially broken down by a series of catabolic reactions into pyruvic acid.

This process generates 2 ATP molecules.

Question 5

What are the 4 steps of cellular respiration in aerobic metabolism?

Answer 5

1. Glycolosis of glucose.
2. Formation of Acetyl Coenzyme A.
3. Krebs cycle
4. Electron transport chain.

Question 6

What molecules does glycolysis produce?

Answer 6

• 2 ATP
• 2 NADH
• 2 Pyruvic acid

Question 7

What is pyruvic acid converted into only if a particular substance is present?

Answer 7

If oxygen is present, the 2 pyruvic acid get converted into 2 Acetyl Coenzyme A.

Question 8

What substance, created by glycolysis, is required to initiate the Krebs cycle?

Answer 8

Acetyl Coenzyme A

Question 9

What molecules do the Krebs cycle produce?

Answer 9

• 2 ATP
• 4 CO2
• 6 NADH
• 2 FADH2

Question 10

What happens to the NADH and FADH2 that is produced by glycolysis and the Krebs cycle?

Answer 10

It is sent to the electron transport chain, which uses these to produce 26 or 28 ATP.

Question 11

If oxygen is not present, what happens to the steps of cellular respiration?

Answer 11

Since no oxygen is present, Pyruvic acid from glycolysis cannot be converted into Acetyl Coenzyme A. This prevents the remaining 3 steps of the aerobic process, and thus only 2 pyruvic acid, 2 ATP and 2 NADH are produced and available.

Question 12

What happens to the pyruvic acid byproduct of glycolysis in anaerobic cell respiration?

Answer 12

The pyruvic acid byproduct becomes lactic acid.

Question 13

What 2 molecules are adenosine composed of?

Answer 13

Adenine and Ribose

Question 14

What is adenosine diphosphate (ADP)?

Answer 14

ADP is created when ATPase catalyses the addition of H2O to ATP. This releases the 3rd phosphate group from the adenosine triphosphate, creating ADP. The overall reaction releases energy.