Pyruvate Dehydrogenase and Acetyl CoA Formation

Flashcards covering key vocabulary and concepts on pyruvate dehydrogenase and acetyl CoA formation.

Pyruvate dehydrogenase

An enzyme complex that converts pyruvate into acetyl CoA, linking glycolysis to the citric acid cycle.

Acetyl CoA

A key metabolite formed from pyruvate that enters the citric acid cycle.

Decarboxylation

The process of removing a carboxyl group from a molecule, often resulting in the release of CO2.

Oxidation

The process of losing electrons or hydrogen, often associated with the release of energy.

Covalent modification

A biochemical regulation mechanism involving the addition or removal of chemical groups to substrates, such as phosphorylation.

Thiamine pyrophosphate (TPP)

A coenzyme involved in the function of the pyruvate dehydrogenase complex; crucial for converting pyruvate to acetyl CoA.

Dihydrolipoyl transacetylase

The component of the pyruvate dehydrogenase complex that transfers the acetyl group to CoA.

NADH

A high-energy electron carrier produced during the conversion of pyruvate to acetyl CoA.

Allosteric regulation

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

Flavin adenine dinucleotide (FAD)

A coenzyme that serves as an electron carrier in various metabolic processes.

High-transfer-potential electrons

Electrons with a high energy level, which are important for generating ATP during cellular respiration.

Aerobic conditions

Metabolic processes that occur in the presence of oxygen.

Anaerobic conditions

Metabolic processes occurring in the absence of oxygen, resulting in fermentation.

Glycolysis

The metabolic pathway that breaks down glucose to form pyruvate.

Citric acid cycle

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

Acetyl groups

Two-carbon units derived from acetyl CoA used in the citric acid cycle.

Regulatory enzyme

An enzyme that controls the speed of a metabolic process by activating or inhibiting other enzymes.

Lipoic acid

A coenzyme that acts in energy metabolism and is a component of the pyruvate dehydrogenase complex.

Pyruvate dehydrogenase kinase

An enzyme that phosphorylates and inactivates the pyruvate dehydrogenase component.

Pyruvate dehydrogenase phosphatase

An enzyme that removes the phosphate group from pyruvate dehydrogenase, activating it.

Supramolecular structures

Complexes formed by multiple molecules that function together in biological systems.

Fatty acids

Long hydrocarbon chains that are important fuels and precursors in metabolism.

Energy charge

The ratio of ATP to ADP and AMP in a cell, indicating its energy status.

Lactic acid

A product of anaerobic metabolism, formed when pyruvate is converted under low oxygen conditions.

Beriberi

A condition resulting from thiamine deficiency, affecting neurological and cardiovascular function.

Epinephrine

A hormone that can activate pyruvate dehydrogenase phosphatase in the liver, promoting the conversion of pyruvate to acetyl CoA.

Cancer metabolism

The altered metabolic pathways utilized by cancer cells, often favoring lactic acid production even in the presence of oxygen.

Flavoproteins

Proteins that contain a flavin group and are involved in redox reactions in cells.

Structured complexity

The intricate organization of multi-enzyme complexes that improves metabolic efficiency.

Hydroxyethyl-TPP

An intermediate formed during the decarboxylation of pyruvate in the pyruvate dehydrogenase reaction.

Citric acid cycle inhibitors

Substances that diminish the activity of the citric acid cycle, impacting energy production.

Metabolic pathways

A series of chemical reactions in a cell that lead to a particular product or to the breakdown of a substrate.