Glycolysis, TCA Cycle, and Oxidative Phosphorylation Lecture Review

Glycolysis

The metabolic pathway that converts glucose into pyruvate, generating small amounts of ATP and NADH.

Substrate-level phosphorylation

A form of ATP synthesis that occurs when a phosphate group is directly transferred from a substrate to ADP.

Hexokinase

An enzyme that phosphorylates glucose to form glucose-6-phosphate, acting as a key regulatory point in glycolysis.

Pyruvate kinase

An enzyme that catalyzes the conversion of phosphoenolpyruvate to pyruvate in the final step of glycolysis, generating ATP.

Anaerobic conditions

Conditions under which glycolysis occurs without oxygen, leading to lactate production and a net gain of ATP from glucose.

Aerobic conditions

Conditions under which glycolysis is followed by the TCA cycle and oxidative phosphorylation, leading to a higher yield of ATP.

Cori Cycle

The metabolic pathway that recycles lactate produced in the muscles back to glucose in the liver.

Acetyl CoA

A central intermediate in metabolism that enters the TCA cycle, produced from pyruvate in the presence of oxygen.

NADH

A reduced coenzyme that carries electrons to the electron transport chain for ATP production.

Regulation of glycolysis

The control of glycolytic enzymes, primarily through allosteric mechanisms and hormonal signals.

2,3-BPG

A compound produced in red blood cells that decreases the affinity of hemoglobin for oxygen, facilitating oxygen delivery.

Oxidative phosphorylation

The process of ATP production that occurs in the mitochondria, driven by electron transport and proton gradients.

Citric Acid Cycle (TCA Cycle)

A series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA.

Glucokinase

An enzyme that phosphorylates glucose in the liver and pancreatic cells, with a higher Km and Vmax compared to hexokinase.

Allosteric regulation

The regulation of an enzyme's activity through the binding of an effector molecule at a site other than the enzyme's active site.

Metabolism

The set of life-sustaining chemical reactions in organisms that involve catabolism (breaking down molecules) and anabolism (building molecules).

ATP synthase

The enzyme that synthesizes ATP from ADP and inorganic phosphate via the proton gradient generated by the electron transport chain.

Lactic acidosis

A condition characterized by the accumulation of lactate in the body, often due to hypoxia or high intensity exercise.

Gluconeogenesis

The metabolic pathway that results in the generation of glucose from non-carbohydrate substrates.

Pyruvate dehydrogenase complex (PDH)

A group of enzymes that converts pyruvate into acetyl-CoA, linking glycolysis to the TCA cycle.

Citrate synthase

The enzyme that catalyzes the first step of the