Glucose

Extracting energy from glucose Two different pathways are involved in the metabolism of glucose: one anaerobic and one aerobic. The anaerobic process occurs in the cytoplasm and is only moderately efficient. The aerobic cycle takes place in the mitochondria and is results in the greatest release of energy. As the name implies, though, it requires oxygen. Anaerobic metabolism Glucose in the bloodstream diffuses into the cytoplasm and is locked there by phosphorylation. A glucose molecule …

…for each starting pyruvate. Energy accounting Each NADH will be oxidized to NAD, generating three ATPs (although it ``costs'' one ATP to transfer the NADHs generated during anaerobic metabolism into the mitochondria for reduction). For each molecule of glucose we can calculate the useable energy produced: Anaerobic Consumed: 2 ATP Produced: 8 ATP _____________________________ Net: 6 ATP Aerobic Consumed: 0 ATP Produced: 2x 15 ATP _____________________________ Net: 30 ATP Thus, for each glucose that enters the muscle, up to 36 ATPs can be generated.