BIOCH 200 Unit 9 - Glycolysis and the PDC (Terms)

Glycolysis

A catabolic pathway occurring in the cytosol that involves the partial oxidation of glucose into two molecules of pyruvate, generating NADH and ATP in small amounts

Gluconeogenesis

The anabolic opposing pathway of glycolysis that reduces pyruvate molecules back to glucose

Hexose Phase

The activation stage of glycolysis in which all intermediates are 6-carbon molecules, serving as an energy investment phase where a small amount of ATP is consumed to activate glucose (reactions 1-4)

Triose Phase

The late stage of glycolysis in which all intermediates are 3-carbon molecules that have been lysed from the hexose phase, serving as an energy payout phase where a net gain in energy is harvested as ATP (reactions 5-10)

Hexokinase

An enzyme that regulates the irreversible phosphoryl transfer reaction of glucose into glucose-6-phosphate found in reaction 1

Phosphoryl Transfer Reaction

A reaction that involves the transfer of a phosphoryl group within a molecule onto a separate molecule with an oxygen group, commonly forming a phosphoester bond

Isomerization

A broad reaction type that involves the change of a molecule to one of its isomers (ex. aldehyde to ketone)

Phosphofructokinase-1 (PFK-1)

An enzyme that regulates the phosphoryl transfer of fructose-6-phosphate to fructose-1,6-bisphosphate in reaction 3 of glycolysis

Pentose Phosphate Pathway

A reaction pathway separate from glycolysis that uses and creates G6P and regenerates NADPH

Acyl Phosphate/Mixed Anhydride

A functional group composed of a phosphate attached to a carboxyl group, formed via the linkage of a phosphate and a carboxylic acid

GAP Dehydrogenase (GAPDH)

An enzyme that regulates the reversible oxidation and phosphorylation reactions of GAP into 1,3-BPG found in reaction 6 of glycolysis

Energy Capture Step

Steps in glycolysis that generate high-energy products (NADH and ATP) that subsequently leave the pathway, which is seen in steps 6, 7, and 10

1,3-Bisphosphoglycerate (1,3-BPG)

A high energy acyl phosphate intermediate formed and consumed within the energy capture phase of glycolysis that releases a large amount of energy upon hydrolysis

Phosphate Transfer Potential

Free energies of hydrolysis for phosphate-containing compounds, representing their energetic capacity and willingness to form ATP via a phosphate transfer

Substrate Level Phosphorylation (SLP)

A coupled phosphate transfer reaction that produces a nucleoside triphosphate

Pyruvate Kinase

An enzyme that regulates the irreversible tautomerization and substrate level phosphorylation of PEP into pyruvate in reaction 10 of glycolysis

Tautomerization

The largely exergonic conversion of one structural isomer to another, typically from an unstable intermediate to a stable product form

Enolpyruvate

The unstable tautomer of pyruvate preliminarily formed in reaction 10 of glycolysis by pyruvate kinase assisted SLP of PEP that decomposes to a stable product form spontaneously

Lactate Dehydrogenase

The enzyme that catalyzes the reversible anabolic reduction of pyruvate into lactate under anaerobic conditions

Pyruvate Dehydrogenase Complex (PDC)

A multienzyme complex found in the mitochondrial matrix that contains catalytic and regulatory enzymes as well as 5 cofactors that catalyzes the pyruvate dehydrogenase reaction

Pyruvate Dehydrogenase Reaction

The process that links glycolysis to the citric acid cycle by which pyruvate is converted to acetyl CoA

Pyruvate Translocase

Transporter protein located on the inner mitochondrial membrane that transports pyruvate into the mitochondrial matrix

Coenzyme A (CoA)

A loosely bound organic cosubstrate with a terminal sulfyhydryl group that forms a thioester bond with acetyl groups

Acetyl-CoA

A high energy intermediate that is the primary reactant of the CAC, structured as an activated form of acetate that is formed via a thioester bond between CoA and acetate

Decarboxylation

The loss of a carboxyl group from a molecule to form CO₂

Transacetylation

The transfer of acetate from one molecule to another