Cellular Respiration Flashcards
What is glycolysis?
Glycolysis is the breakdown of glucose to pyruvate in the cytoplasm.
Describe ATP’s involvement in cellular respiration.
ATP is required for the phosphorylation of glucose and intermediates during the energy investment phase of glycolysis. This leads to the generation of more ATP during the energy pay-off stage and results in a net gain of ATP.
What happens to pyruvate in aerobic conditions?
The pyruvate is broken down to an acetyl group that combines with coenzyme A forming acetyl coenzyme A.
What does the acetyl group from acetyl coenzyme A combine with and then form?
The acetyl group combines with oxaloacetate to form citrate.
What happens to the citrate after it is formed?
Through a series of enzyme-controlled steps, citrate is gradually converted back into oxaloacetate which results in the generation of ATP and release of carbon dioxide.
Where does the citric acid cycle occur?
It occurs in the matrix of the mitochondria.
What do dehydrogenase enzymes do in both glycolysis and the citric acid cycle?
They remove hydrogen ions and electrons and pass them to the coenzyme NAD, forming NADH.
Where are the hydrogen ions and electrons from NADH passed?
They are passed to the electron transport chain on the inner mitochondrial membrane.
Describe the electron transport chain.
It is a series of carrier proteins attached to the inner mitochondrial membrane. Electrons are passed along it, releasing energy. The energy allows Hydrogen ions to be pumped across the inner mitochondrial membrane.
How is ATP synthesised?
The flow of the hydrogen ions through the membrane protein ATP synthase results in the production of ATP.
What happens to the hydrogen ions and electrons after the electron transport chain?
They combine with oxygen to form water.
What happens instead of aerobic respiration if there is no oxygen?
Fermentation takes place in the cytoplasm.
Describe fermentation in animal cells.
Pyruvate is converted to lactate in a reversible reaction.
Describe fermentation in plant and yeast cells.
Ethanol and CO2 are produced in an irreversible reaction.
Name a difference between fermentation and aerobic respiration.
Fermentation results in much less ATP being produced than in aerobic respiration.
