Krebs Cycle

Where does the Krebs cycle take place?

Matrix of the mitochondria

What happens during the Krebs cycle?

Remaining carbon molecules are broken down into CO₂ in energy-extracting reactions

What is another name for the Krebs cycle?

Citric acid cycle

Why is it called the citric acid cycle?

Citric acid is the first compound formed in the cycle

What combines with acetyl-CoA to start the cycle?

A 4-carbon molecule called oxaloacetate

What does acetyl-CoA + oxaloacetate form?

Citric acid (6-carbon molecule)

What happens to citric acid during the cycle?

It is broken into a 5-carbon compound, then a 4-carbon compound

How many CO₂ molecules are released per turn?

2 CO₂

What happens to the 4-carbon molecule at the end of the cycle?

It combines with a new acetyl-CoA to restart the cycle

How many times is water added per turn?

3 times

Why is water added during the cycle?

To break bonds and rearrange atoms

What forms of energy are produced during the Krebs cycle?

ATP, NADH + H⁺, and FADH₂

How many ATP are produced per turn?

1 ATP

How many turns of the Krebs cycle occur per glucose molecule?

2 turns

Why are there 2 turns per glucose?

Each glucose produces 2 pyruvic acids, and each pyruvic acid becomes 1 acetyl-CoA

Total ATP produced from the Krebs cycle per glucose?

2 ATP

Total CO₂ produced from the Krebs cycle per glucose?

4 CO₂

Total NADH + H⁺ produced per glucose?

6 NADH + H⁺

Total FADH₂ produced per glucose?

2 FADH₂

What is the role of NAD⁺ and FAD in the Krebs cycle?

They accept high-energy electrons and H⁺ to form NADH + H⁺ and FADH₂

Where do NADH + H⁺ and FADH₂ go after the Krebs cycle?

Electron transport chain

What are the reactants for 2 turns of the Krebs cycle?

2 acetyl-CoA; 6 water molecules

How many pairs of hydrogen atoms are carried by NAD⁺ or FAD in 2 turns?

8 pairs of hydrogen atoms

How many NADH + H⁺ are produced in 2 turns?

6 NADH + H⁺

How many FADH₂ are produced in 2 turns?

2 FADH₂

How many ATP are produced in 2 turns?

2 ATP