Krebs Cycle Steps

Question 1

Step 1

Answer 1

Acetyl-CoA combines with oxaloacetate, water is added and CoA is removed to form citrate

Question 2

Step 2

Answer 2

Citrate rearranges to form isocitrate

Question 3

Step 3

Answer 3

Isocitrate loses carbon dioxide and 2 hydrogen atoms forming

reduced NAD and “-ketoglutarate

Question 4

Step 4

Answer 4

“-ketoglutarate loses CO2 and H while gaining water and
forming reduced NAD and succinate
-Energy is transferred to guanosine triphosphate (GTP), a nucleotide similar to ATP

Question 5

Step 5

Answer 5

Succinate loses 2 more H atoms, forming FADH + H+ and fumarate

Question 6

Step 6

Answer 6

Fumarate gains water to form malate

Question 7

Step 7

Answer 7

Malate loses 2 H atoms, forming reduced NAD

and oxaloacetate, which can combine with acetyl- CoA to start the cycle over again