Substrate Level and Oxidative Phosphorlyation

Substrate-Level Phosphorylation

A metabolic process that generates ATP by directly transferring a phosphate group to ADP from a phosphorylated intermediate.

Oxidative Phosphorylation

The process by which ATP is produced using energy derived from the electron transport chain, involving electron transfer and the formation of a proton gradient.

Final Electron Acceptor

In cellular respiration, this is oxygen, the most electronegative atom, which accepts electrons at the end of the electron transport chain.

Chemiosmosis

The movement of protons across a membrane, which generates ATP via ATP synthase, using the energy stored in a proton gradient.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, yielding a small amount of ATP and NADH.

Hexokinase

An enzyme that catalyzes the phosphorylation of glucose to form glucose-6-phosphate, effectively trapping glucose in the cell.

Phosphofructokinase

A key regulatory enzyme in glycolysis that catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, consuming ATP.

Dihydroxyacetone Phosphate (DHAP)

One of the two 3-carbon molecules produced during glycolysis, which can be converted to glyceraldehyde-3-phosphate.

Glyceraldehyde-3-Phosphate (G3P)

A three-carbon sugar that is produced in glycolysis and is an important intermediate in metabolic pathways.

Pyruvate

The end product of glycolysis, which can enter the pyruvate dehydrogenase complex for further processing in cellular respiration.

Enzyme

A biological catalyst that accelerates chemical reactions in cells, often by lowering the activation energy.

Dehydrogenase

An enzyme that catalyzes the removal of hydrogen from a substrate, typically involved in oxidation-reduction reactions.

ATP Investment Phase

The initial stage of glycolysis where ATP is consumed to phosphorylate glucose and its derivatives.

Energy Production Phase

The later stage in glycolysis where ATP is produced, resulting in a net gain of ATP.

Kinase

An enzyme that transfers phosphate groups from high-energy donor molecules, like ATP, to specific substrates.

Citric Acid Cycle

A metabolic cycle that generates energy through the oxidation of acetyl-CoA derived from pyruvate, producing NADH and FADH2.

Mitochondrial Matrix

The space within the inner membrane of the mitochondria where the Krebs cycle and oxidative phosphorylation occur.