2.2: Cellular Respiration Flashcards
Describe the role of ATP
To transfer energy from cell respiration to anabolic pathways and other cell processes which require energy
What are the 3 stages of aerobic respiration
Glycolysis
Citric acid cycle
electron transport chain
Where are the 3 stages of aerobic respiration take place?
Glycolysis- cytoplasm
Citric acid cycle- matrix of the mitochondria
Electron transport chain- inner mitochondrial membrane
Describe glycolysis
glycolysis uses energy in the energy investment phase to the intermediate stage. From then on the phosphorylation of phosphate happens in the energy pay-off phase
What happens to pyruvate in aerobic respiration (O2 present)
it gets broken down to an acetyl group which then combines with coenzyme A to make acetyl coenzyme A.
Describe what occurs during the citric acid cycle
the acetyl-coenzyme turns into citrate. Using a series of enzyme-controlled steps the citrate slowly turns back into oxaloacetate while giving off CO2, ATP and NADH.
Describe the role of the dehydrogenase enzymes
They remove hydrogen ions and electrons and pass them to the coenzyme NAD which forms NADH
Describe what the electron transport chain is
a series of carrier proteins attached to the inner mitochondrial membrane.
Describe what happens at the electron transport chain
Electrons are passed along the electron transport chain releasing energy
The energy allows hydrogen ions to be pumped across the inner mitochondrial membrane
The flow of these ions back through the membrane protein ATP synthesis results in the production of ATP
Finally, hydrogen ions and electrons combine with oxygen to form water
Describe the conditions under which fermentation will take place
when there is no oxygen present
State where in a cell fermentation will take place
cytoplasm
Describe fermentation in animals
the pyruvate is converted to lactate in a reversible reaction meaning lactate can turn back into pyruvate
Describe fermentation in plants and yeast cells
carbon dioxide and ethanol is produced in an irreversible reaction
what is meant by phosphorylation
the addition of a phosphate group
Explain why the phosphorylation of intermediates in glycolysis is referred to as the energy investment stage.
it requires ATP to provide the phosphate to phosphorylate glucose and intermediate
