Pyruvate Oxidation

🧠 In Total: Pyruvate Oxidation Makes…

For 1 pyruvate:

• 1 CO₂

• 1 NADH

• 1 Acetyl-CoA

BUT remember: Glycolysis makes 2 pyruvate, so this happens twice per glucose molecule

🧠 Key Understanding:

A transition step that converts pyruvate into acetyl-CoA, producing NADH and CO₂.

Where does pyruvate oxidation take place?

In the mitochondria.

Why this matters:

• You can’t enter the Krebs cycle without converting pyruvate to acetyl-CoA

• It’s like changing clothes before entering the next level 😂

• You’re also making NADH, which will be used later to make ATP in the electron transport chain

How it happens

• Pyruvate moves from the cytoplasm into the mitochondrion

  • Glycolysis happens in the cytoplasm

  • Pyruvate enters the mitochondria where cellular respiration continues

• One carbon is removed from pyruvate

  • That carbon becomes CO₂, which gets released as waste (you breathe it out)

• Electrons are taken from pyruvate by NAD⁺

  • NAD⁺ becomes NADH, holding onto high-energy electrons for later use

• The 2-carbon leftover is joined with Coenzyme A

  • This makes acetyl-CoA — which enters the Krebs cycle (also called citric acid cycle)

What molecules are needed for pyruvate oxidation?

Pyruvate, NAD⁺, and Coenzyme A (CoA)

What happens to NAD⁺ during pyruvate oxidation?

It gets reduced to NADH by picking up electrons.

: Why is pyruvate oxidation important?

It links glycolysis to the Krebs cycle and helps produce energy-carrying molecules.

What would happen if pyruvate couldn't enter the mitochondria?

“If pyruvate couldn't enter the mitochondria, pyruvate oxidation wouldn’t happen. That means no acetyl-CoA would be made, and the Krebs cycle couldn’t run. The cell would have to switch to anaerobic respiration like fermentation to make ATP.”