Step 3: Kreb's Cycle Aka Citric Acid Cycle

Question 1

Where exactly does Step 3 (Kreb’s cycle) occur?

Answer 1

In the matrix of the mitochondrian

Question 2

What is Coenzyme A’s function in Kreb’s cycle and in Aerobic Cellular Respiration in general?

Answer 2

To feed Acetyl into the matrix to start the cycle.

Coenzyme A then returns to the inter membranes structure space to grab more Acetyls to restart the process.

Question 3

What does Acetyl do in the matrix cycle?

Answer 3

1. Acetyl meets up with a 4carbon compound called oxaloacetate.
2. The two then bond to form a 6carbon compound called citric acid.

Question 4

How many ATPs are produced in the Kreb’s cycle?

Answer 4

2 ATPs are produced

Question 5

What happens in between the meeting of Acetyl and oxaloacetate?

Answer 5

1. Acetyl bonds with 7 other molecules before oxaloacetate.

Question 6

How does Acetyl remain a 2C molecule after bonding 7 times?

Answer 6

CO2 is lost 2 times during those 7 bonds, so Acetyl remains a 2C molecule when it reaches oxaloacetate.
8 Hydrogen per Acetyl are lost (total 16)

Question 7

What rushes into the matrix during the Kreb’s cycle?

Answer 7

Water (H2O) rushes in

Question 8

What happens into the 16 Hydrogen molecules?

Different from steps 1&2

Answer 8

They are picked up by NAD and FAD

Which become NADH2 and FADH2

Question 9

What is the main function of the Kreb’s cycle?

Answer 9

To rip off the hydrogen molecules from the Acetyl