Krebs Cycle

Question 1

Where does the krebs cycle take place?

Answer 1

in the matrix of the mitochondria

Question 2

What is the first step in the krebs cycle?

Answer 2

2-carbon acetylcoenzyme A from link reaction combines with a 4-carbon molecule to produce citrate

Question 3

What is the second step in the krebs cycle?

Answer 3

citrate loses is decarboxylated and dehydrogenated to form a 4-carbon molecule
single molecule of ATP produced from substrate-level phosphorylation

Question 4

What is the final step in the krebs cycle?

Answer 4

4-carbon molecule can now combine with acetylcoenzyme A to begin the cycle again

Question 5

What are the yields for the krebs cycle (for each molecule of pyruvate)?

Answer 5

3 NADH
2 CO2
1 FADH
1 ATP

Question 6

What is a coenzyme?

Answer 6

a molecule that some enzyme require in order to function

Question 7

Name three examples of coenzymes

Answer 7

NAD - respiration
FAD - krebs
NADP - photosynthesis

Question 8

What does NAD do?

Answer 8

works with dehyrogenase enzymes that catalyse the removal of hydrogen ions from substrates
transfers them to other molecules through oxidative phosphorylation

Question 9

Why is the krebs cycle significant?

Answer 9

breaks down macromolecules into smaller ones
produces H atoms that are carried by NAD to the elctron transport chain
regenerates the 4-carbon molecule that combines with acetylcoenzyme A