respiration Flashcards
(40 cards)
what is aerobic respiration?
- respiration which requires oxygen and produces carbon dioxide, water and ATP
what is anaerobic respiration?
-takes place in absence of oxygen, and produce lactate in animals, or ethanol and carbon dioxide in plants and fungi
-does not produce a lot of atp
what are the four stages of aerobic respiration?
- glycolysis
- link reaction
- krebs cycle
- oxidative phosphorylation
where does glycolysis occur?
- in the cytoplasm of the cell
where does the link reaction occur?
in the matrix of the mitochondria
where does the krebs cycle occur?
in the matrix of the mitochondria
where does oxidative phosphorylation happen in aerobic respiration?
in the membrane of the cristae of the mitochondria
what are coenzymes?
complex organic molecules needed for some enzymes to function, which accept or donate hydrogen
how are the stages of aerobic respiration linked?
- carrier molecules transfer substrates between the three pathways
- NAD used as a hydrogen acceptor
- reduced NAD used as hydrogen donator for last stage where most ATP synthesised
what is glycolysis?
- first stage of aerobic and anaerobic respiration
- splitting of glucose
describe what happens in glycolysis
- phosphorylation of glucose;
2x phosphate molecules from hydrolysis of ATP, produces 1x glucose phosphate and 2x ADP - glucose phosphate split into 2x triose phosphate
- oxidation of triose phosphate;
triose phosphate added to 2x ADP and 1x NAD, produced 2x ATP 1x reduced NAD and 1x pyruvate per triose phosphate
what is the net production from glycolysis?
- 2 ATP
- 2 reduced NAD
- 2 pyruvate
what is the purpose of the link reaction?
- to link glycolysis to the krebs cycle
how does pyruvate move from glycolysis?
- actively transports from cytoplasm to matrix of mitochondria
what happens in the link reaction?
- pyruvate oxidised to produce acetate;
pyruvate loses a carbon molecule and 2x hydrogen, forms a molecule of carbon dioxide and 1x reduced NAD - acetate combines with coenzyme A to produce acetylcoenzyme A
- acetylcoenzyme A moves onto Krebs cycle
- happens 2x per glucose molecule
what is net production per glucose molecule at the end of the link reaction?
- 2x acetylcoenzyme A
- 4x reduced NAD
- 2x carbon dioxide
what happens in the Krebs cycle?
- Acetylcoenzyme A combines with 4c compound oxaloacetate, coenzyme A released
- produces 6c compound citrate which enters Krebs cycle
- series of redox reactions cause this molecule to lose carbon dioxide and hydrogen to result in oxaloacetate which can restart the cycle
what are the products of the Krebs cycle?
- 1x ATP
- 3x reduced NAD
- 1x reduced FAD
- 2x carbon dioxide
what is the way of making ATP in the krebs cycle called?
substrate level phosphorylation
what is the net production of one glucose molecule after the krebs cycle?
- 6x carbon dioxide
- 4x ATP
- 10x reduced NAD
- 2x reduced FAD
what is the significance of the krebs cycle?
- breaks macromolecules into smaller ones (pyruvate to CO2)
- produces hydrogen for coenzymes for oxidative phosphorylation for ATP production
- regenerates oxaloacetate
how many molecules of carbon in pyruvate?
3
how many molecules of carbon are in acetate?
2
what happens in oxidative phosphorylation?
- coenzymes deposit hydrogen molecules to the electron transport chain
- energy from electrons within hydrogen atoms converted to ATP
