key term - Citric acid cycle

Definition

The citric acid cycle, also known as the Krebs cycle or TCA cycle, is a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. It takes place in the mitochondria and produces high-energy molecules such as NADH and FADH2.

5 Must Know Facts For Your Next Test

1. The citric acid cycle occurs in the mitochondrial matrix.
2. Each turn of the cycle generates 3 NADH, 1 FADH2, and 1 GTP (or ATP).
3. Acetyl-CoA combines with oxaloacetate to form citrate at the start of the cycle.
4. CO2 is released during specific steps in the cycle as a waste product.
5. NADH and FADH2 produced in the cycle are crucial for ATP production in oxidative phosphorylation.

Review Questions

Related terms

Oxidative Phosphorylation: The process where ATP is formed as electrons are transferred to oxygen by electron carriers like NADH and FADH2.

Acetyl-CoA:

A molecule that conveys carbon atoms within the acetyl group to be oxidized for energy production.

Mitochondria: Organelles known as the powerhouses of cells where respiration and energy production occur.