Chapter 16

Glycolysis

A 10-step process that breaks down glucose into pyruvate, making ATP and NADH.

Hexokinase

First enzyme in glycolysis; adds a phosphate to glucose to trap it in the cell.

Kinase

An enzyme that transfers a phosphate group, usually from ATP, to another molecule.

Phosphofructokinase (PFK)

Key regulatory enzyme in glycolysis; commits glucose to breakdown by adding a second phosphate.

Thioester intermediate

A high-energy molecule formed during reactions like acetyl-CoA production; helps drive the next step.

Substrate-level phosphorylation

Direct transfer of a phosphate to ADP to make ATP—no oxygen needed.

Mutase

An enzyme that moves a functional group (like phosphate) within a molecule.

Enol phosphate

A high-energy intermediate that helps generate ATP in glycolysis.

Pyruvate kinase

Final enzyme in glycolysis; makes ATP and pyruvate from phosphoenolpyruvate (PEP).

Alcoholic fermentation

Converts pyruvate to ethanol and CO₂; used by yeast when oxygen is absent.

Lactic acid fermentation

Converts pyruvate to lactate; used by muscles and bacteria in low oxygen.

Obligate anaerobe

Organism that dies in oxygen; relies only on anaerobic processes like fermentation.

Where does glycolysis occur?

In the cytoplasm