Respiration Flashcards
Where does respiration take place?
Mitochondria - the folds (cristae) provide a large surface area
What coenzymes are used in respiration?
NAD and FAD transfer hydrogen between molecules. Coenzyme A transfers acetate between molecules.
What are the four stages in aerobic respiration?
- Glycolysis
- Link Reaction
- Krebs Cycle
- Oxidative Phosphorylation
What are the stages in anaerobic respiration?
- Glycolysis
What happens in glycolysis?
This occurs in cytoplasm of cells. It is an anaerobic process.
- Phosphorylation - Glucose is phosphorylated by adding 2 molecules of Pi from ATP. 2 molecules of TP and ADP are formed.
- Oxidation - TP is oxidised, forming 2 molecules of pyruvate. NAD collects H+ to form NADH. 4 ATP are produced but 2 were used in stage one. net gain of 2 ATP.
What are the products of glycolysis and where do they go?
2 x NADH to oxidative phosphorylation
2 x pyruvate to the link reaction
2 x ATP used for energy
What happens in the link reaction?
Converts pyruvate to acetyl coenzyme A by decarboxylating it.
NAD is reduced changing pyruvate to acetate.
Acetate is combines with coenzyme A for form acetyl CoA
Two pyruvate molecules are made for every glucose molecules that enters glycolysis.
What are the products of the link reaction and where do they go?
2 x acetyl coA to the krebs cycle
2 x carbon dioxide released as waste product
2 x NADH to oxidative phosphorylation
What are the stages of the Krebs Cycle?
- Formation of citrate - acetyl coA combines with oxaloacetate to form citrate. Coenzyme A goes back to link reaction to be used again.
- Formation of a 5-carbon compound - Decarboxylation occurs, where CO2 is removed. Dehydrogenation also occurs. Hydrogen is used to produce NADH from NAD.
- Regeneration of oxaloacetate - decarboxylation and dehydrogenation occurs producing FADH and 2 x NADH. ATP is produced by the direct transfer of phosphate group to ADP.
