Unit One - Key Area 7 Flashcards
What are the three main pathways of aerobic respiration?
Glycolysis, the citric acid cycle and the electron transport chain
Where does glycolysis take place?
cytoplasm
Where does the citric acid cycle take place?
matrix of the mitochondria
Where does the electron transport chain take place?
inner membrane of the mitochondria
What is glycolysis?
the breakdown of glucose to pyruvate
Describe the energy investment phase of glycolysis
ATP is required for the phosphorylation of glucose and intermediates.
Describe the energy pay-off phase of glycolysis
More ATP is produced and there is an overall net gain of ATP
Describe the role of dehydrogenase enzymes in glycolysis
dehydrogenase enzymes remove hydrogen ions and electrons and pass them to the coenzyme NAD, forming NADH. NADH passes the electrons and hydrogen ions to the electron transport chain.
Describe the citric acid cycle
Pyruvate is broken down into an acetyl group that combines with coenzyme A, forming acetyl coenzyme A.
The acetyl group from acetyl coenzyme A then combines with oxaloacetate to form citrate.
A series of enzyme controlled steps converts citrate back into oxaloacetate, generating ATP and releasing carbon dioxide.
Dehydrogenase enzymes remove hydrogen ions and electrons and pass them to the coenzyme NAD, forming NADH, which in turn pass them to the electron transport chain
What is the electron transport chain?
a series of carrier proteins on the inner mitochondrial membrane.
What happens during on the 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 return flow of these ions back through the membrane protein ATP synthase results in the production of ATP. The returning hydrogen ions and low energy electrons combine with oxygen to form water.
