AP Syllabus focus:
‘Glycolysis releases energy in glucose, forming ATP, NADH, and pyruvate in the cytosol.’
Glycolysis is a core energy-harvesting pathway that begins glucose breakdown without requiring oxygen.
Overview diagram of glycolysis showing glucose being converted into two pyruvate molecules. It highlights the two main phases (energy investment and energy payoff) and visually tracks ATP usage/production and NADH formation across the pathway. Source
Practice Questions
FAQ
Phosphorylation raises the energy of intermediates and helps destabilise glucose for later splitting.
It also helps retain the sugar inside the cell by adding charged phosphate groups.
They rely on glycolysis in the cytosol for essentially all ATP production.
NAD$^+$ is regenerated by converting pyruvate to lactate to keep glycolysis running.
Two ATP are consumed to phosphorylate early intermediates.
Four ATP are later produced by substrate-level phosphorylation, giving $4-2=2$ net.
Several intermediates can be diverted as carbon skeletons for building molecules.
Examples include precursors for certain amino acids and lipid-related backbones.
It occurs in the cytosol and does not require oxygen or membrane-bound organelles.
Its broad distribution across diverse organisms suggests early origin and strong conservation.
