biology / Molecules of Life / free

Metabolism

Connect many small reactions into the pathways that build and power a cell.

Follow the mechanism1 / 3

A nutrient enters a reaction network. Cells route carbon compounds through linked reactions rather than releasing all of their chemical energy at once. Enzymes and compartments make selected routes possible and controllable.

metabolic pathwaybalanced flux · coupling

Focus the idea

carbon flux74

electrons61

ATP balance+2

building2

Fuel availability 74%Electron acceptor 78%ATP demand 42%Pathway regulation 72%Pathway time 68%

The pathway captures 44 ATP-equivalent output against demand 42. Electron acceptor availability controls how much redox energy can be coupled to ATP, so a high fuel supply alone does not guarantee high usable energy.

This is a normalized pathway model, not a complete map of human metabolism. Real cells branch into many pathways, compartmentalize reactions, use redox pairs such as NAD⁺/NADH, regulate flux allosterically, and exchange metabolites with the environment.

04 / PRACTICE

Make the biology yours.

0 / 3 checked

Answer from the model, then use the explanation to connect the visual mechanism to the biological rule.

CHECK 1 / 3

Metabolism

Make the biology yours.

What does an electron acceptor make possible in a catabolic pathway?