Krebs Cycle

Question 1

Krebs cycle

Step 1?

Answer 1

• begins with acetyl-CoA reacting with oxaloacetate to form citrate
• CoA is removed

Question 2

Krebs cycle

Step 2?

Answer 2

-citrate undergoes isomerization to form isocitrate

Question 3

Krebs cycle

Step 3?

Answer 3

• through redox isocitrate is oxidized to alpha ketogluterate
• NAD+ from matrix is reduced, forming NADH

Question 4

Krebs cycle

Step 4?

Answer 4

• alpha-ketogluterate binds with CoA and is oxidized by NAD+
• NAD+ is reduced to NADH
• Co2 is removed

Question 5

Krebs cycle

Step 5?

Answer 5

• phosphate displaces CoA from succinyl CoA
• GDP is phosphorylated to GTP
• phosphate group transferred to ADP forming ATP

Question 6

Krebs cycle

Step 6?

Answer 6

• FAD oxidizes succinate to form FADH2

- succinate becomes fumarate

Question 7

Krebs cycle

Step 7?

Answer 7

-water is added to fumarate to form Malate

Question 8

Krebs cycle

Step 8?

Answer 8

• Malate undergoes redox reaction with NAD+ to produce NADH and oxoaloacetate
• ready for cycle to begin again

Question 9

Krebs cycle

Summary?

Answer 9

-6NADH
-2ATP
-2FADH2
For each molecule of glucose

Question 10

Krebs cycle

Krebs cycle?

Answer 10

• 3rd stage in cellular respiration
• series of 8 reactions
• for every glucose molecule that enters, 2 cycles must occur
• occurs in matrix
• 8steps