Kreb’s Cycle

Question 1

For every molecule of glucose, how many times does the Kreb’s cycle turn?

Answer 1

Twice

Question 2

Describe the Kreb’s cycle

Answer 2

8-step process in which the entire glucose molecules is oxidized and the carbon is converted into CO2. As glucose is oxidized, NADH and FADH2 receive those electrons and are reduced. These reduced molecules then enter the ETC

Question 3

What are the total yields (of both acetyl molecules) in the Kreb’s cycle?

Answer 3

2 ATP (through SLP), 6 NADH reduced, 2 FADH2 reduced, 4 total CO2 gone

Question 4

Describe all the steps of the Kreb’s cycle

Answer 4

1. The 2C acetyl group of acetyl-CoA condensed with 4C oxaloacetate to form 6C citrate
2. 6C citrate is rearranged to 6C isocitrate
3. 6C isocitrate is converted to 5C α-ketoglutarate by losing a CO2 and two hydrogen atoms that reduce NAD+ to NADH
4. 5C α-ketoglutarate is converted to 4C succinyl-CoA. A CO2 is removed, CoA is added, and two hydrogen atoms reduce NAD+ to NADH
5. 4C succinyl CoA is converted to 4C succinate. ATP is formed by SLP and CoA is released
6. 4C succinate is converted to 4C fumarate. Two hydrogen atoms reduced FAD to FADH2
7. 4C fumarate is converted to 4C malate
8. 4C malate is converted to 4C oxaloacetate. Two hydrogen atoms reduce NAD+ to NADH

Question 5

Draw a diagram of the Citric Acid Cycle