SESSION 12

Glycolysis

The metabolic process occurring in the cytosol that breaks glucose into two pyruvate molecules, yielding 2 ATP and 2 NADH.

Phosphofructokinase

The enzyme that regulates glycolysis through feedback inhibition; high ATP levels inhibit its activity.

Citric Acid Cycle

A series of reactions in the mitochondrial matrix where Acetyl CoA produces 6 NADH, 2 FADH2, and 2 ATP, with CO2 as a byproduct.

NADH

A high-energy intermediate that stores energy for the Electron Transport Chain and is produced during glycolysis and the citric acid cycle.

FADH2

Another high-energy intermediate that stores energy for the Electron Transport Chain, produced in the citric acid cycle.

Electron Transport Chain (ETC)

A series of protein complexes that transfer electrons from NADH and FADH2, pumping protons to create an electrochemical gradient.

Oxidative Phosphorylation

The process where protons flow through ATP synthase, utilizing the generated gradient to convert ADP to ATP.

Oxygen

The final electron acceptor in the Electron Transport Chain; without it, cells resort to fermentation.

Fermentation

An anaerobic process that yields 2 ATP per glucose, significantly less energy-efficient than cellular respiration.

Cellular Respiration

The process that releases energy from glucose to produce approximately 29 ATP, which is much more efficient than fermentation.

ATP Synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate by utilizing energy from the proton gradient.

Endergonic

Refers to the process of photosynthesis that stores energy in glucose molecules.

Exergonic

Refers to the process of cellular respiration that releases energy from glucose to produce ATP.

Feedback Inhibition

A regulatory mechanism where the accumulation of a product inhibits an enzyme involved in its synthesis.

Proton Gradient

The electrochemical gradient established across the mitochondrial membrane, crucial for ATP production during oxidative phosphorylation.