Glycolysis, Link Reaction & Krebs Cycle
Glycolysis kicks off in your cell's cytoplasm because glucose can't actually squeeze through mitochondrial membranes. The process starts by adding two phosphate groups to glucose using ATP, creating hexose diphosphate that splits into two triose phosphate molecules.
The link reaction happens in the mitochondrial matrix where pyruvate gets modified. It loses a carbon (forming CO₂), gets stripped of hydrogen (making reduced NAD), and combines with coenzyme A to form acetyl CoA.
The Krebs cycle is where the real action happens - acetyl CoA joins with a 4-carbon acid to make a 6-carbon compound. Through two decarboxylation steps and four dehydrogenation reactions, each cycle produces 1 ATP, 3 reduced NAD molecules, 1 reduced FAD, and 2 CO₂ molecules.
Quick Tip: Remember that glucose produces two pyruvate molecules, so the Krebs cycle actually runs twice per glucose molecule, doubling all the products!
