Cellular respiration-Human biology Unit 1

Three pathways of aerobic respiration

• Glycolysis

• Citric acid cycle

• Electron transport chain

Glycolysis location

cytoplasm

energy investment phase

2 ATP is required for the phosphorylation of glucose

energy pay off phase

glucose is broken down into pyruvate making a net gain of 2 ATP

Dehydrogenase enzymes

remove hydrogen ions, giving them to NAD, making NADH, which is passed to the electron transport chain, this happens during glycolysis and the citric acid cycle

Citric acid cycle

pyruvate breaks down into an acetyl group that combines with coenzyme A, forming acetyl-CoA, which then combines with oxaloacetate to produce citrate through a series of enzyme-controlled steps. Citrate is converted back to oxaloacetate, which generates ATP and releases carbon dioxide

citric acid cycle location

matrix of the mitochondria

what is the electron transport chain

The electron transport chain is a series of carrier proteins attached to the inner mitochondrial membrane

electron transport chain

• Electrons are passed along the electron transport chain releasing energy.

• This energy allows hydrogen ions to be pumped across the inner mitochondrial membrane.

• The flow of these ions back through the membrane protein ATP synthase results in the production of ATP.

• Finally, the hydrogen ions and electrons combine with oxygen to form water.

electron transport chain location

inner mitochondrial membrane