L16 Krebs Cycle

Krebs Cycle

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins.

Oxaloacetate

A four-carbon molecule that combines with acetyl CoA to form citrate at the beginning of the Krebs cycle.

Acetyl CoA

A two-carbon molecule that enters the Krebs cycle, playing a crucial role in energy production.

Citrate

The six-carbon compound formed from the combination of oxaloacetate and acetyl CoA.

Decarboxylation

The process of removing a carboxyl group from a molecule, releasing CO2, which occurs multiple times in the Krebs cycle.

Electron transfer

The movement of electrons from NADH and FADH2 through the electron transport chain to oxygen, crucial for ATP production.

Isocitrate Dehydrogenase

An enzyme that catalyzes the oxidative decarboxylation of isocitrate in the Krebs cycle.

Reduction Potential

A measure of the tendency of a chemical species to acquire electrons and thereby be reduced; important in determining the energetics of the Krebs cycle.

Proton Motive Force

The force generated by the concentration gradient of protons across a membrane, driving ATP synthesis in mitochondria.

NADH

An electron carrier that plays a crucial role in the Krebs cycle, transferring high-energy electrons to the electron transport chain.

FADH2

Another electron carrier similar to NADH, which transfers electrons to the electron transport chain at a different point.

Cytochrome c

A small heme protein involved in the electron transport chain, facilitating electron transfer between Complex III and IV.

Complexes I, III, and IV

Key protein complexes in the electron transport chain responsible for transferring electrons and pumping protons across the mitochondrial membrane.

Mitochondrial matrix

The innermost compartment of the mitochondria where the Krebs cycle occurs.

GTP

Guanosine triphosphate, a high-energy molecule produced in the Krebs cycle that can be converted to ATP.

Endosymbiotic theory

The hypothesis that mitochondria originated from free-living bacteria that entered into a symbiotic relationship with ancestral eukaryotic cells.

What is the Krebs Cycle?

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins.