How many carbon atoms are in an oxaloacetic acid molecule, which joins with an acetyl group during step 1 of the Krebs cycle?

Carbon dioxide released by respiration just equals the quantity required by photosynthesizing cells. This is termed:

FADH2 is produced during:

NADH is oxidized by:

The electron transport chain occurs in:

A process that uses membranes to couple redox reactions to ATP production is termed: