respiration😏😏 Flashcards
(60 cards)
where is the electron transport chain in respiration
inner mitochondrial membrane
why does aerobic respiration yield fewer molecules of ATP than theoretical maximum
- some ATP used to actively transport pyruvate into mitochondria
- some ATP used to actively transport H+ from NADH formed in glycolysis into mitochondria
- not all NADH used to feed into ETC, some released as heat
why does anaerobic respiration yield less ATP than aerobic respiration
- in anaerobic, glycolysis occurs producing 2 net ATP
- only substrate level phosphorylation occurs
- no oxygen available as final electron acceptor
- oxidative phosphorylation does not occur
- pyruvate used to regenerate NAD for glycolysis
why are parasites that live in the blood of mammals adapted to respire anaerobically despite oxygen being carried in the blood
- parasites have little access to oxygen
- not much oxygen dissolved in plasma
- oxygen is combined with Hb
why can the anaerobic pathway in animals be reversed but not in yeast
in animals
- pyruvate converted to lactate
- can be reversed as no other products
- lactate dehydrogenase to reverse
in yeast
- pyruvate converted to ethanal and co2
- cannot be reversed as co2 lost
why is lactate converted to glucose in hepatotcytes rather than in the respiring cells where it is produced
- hepatocytes can tolerate lactate
- hepatocytes have enzymes to metabolise lactate
what might happen if the liver did not break down insulin after it was used
- blood glucose would fall below normal
- insulin would continue converting glucose to glycogen for storage
- cannot generate enough ATP as not enough glucose
- coma/death
consequences for liver metabolism if person has high alcohol intake
- build up of fatty acids results in fat deposits in liver cells
- ornithine cycle cannot occur
- build up of lactate kills liver cells
where in liver cells is excess NADH reoxidised
inner mitochondrial membrane
why is respiration rate low at 6 degrees
- not enough kinetic energy for ESC
- respiration uses enzymes
why does respiration stop at 90 degrees
-enzymes denatured
in the anaerobic yeast pathway what is the hydrogen acceptor
ethanal
why is the anaerobic pathway important for plant cells
- allows some ATP to be produced in glycolysis
- ATP needed for metabolic processes such as active transport
where in aerobic respiration is co2 produced
krebs cycle and link reaction
why is there more respiration at a higher temperature
- enzymes involved
- more kinetic energy for ESC
why would wet pea seeds respire more than dry pea seeds
- reactions need to take place in water
- enzymes and substrate can move in water
- soaked seeds need more ATP
benefits of anaerobic respiration
- ATP still produced
- allows glycolysis to continue
role of coenzymes in a leaf cell
- CoA transports acetyle to Krebs cycle
- NAD accepts H
- NADH carries electrons to ETC
- NADH carries H+ for oxidative phosphorylation
- NADPH carries H to Calvin cycle
explain role of ATP in cell
- transfers energy
- phosphates removed by hydrolysis
- energy released for active transport
- energy released in small packets
- ADP can attach phosphate during respiration
process carried out by cristae
oxidative phosphorylation
describe how an endotherm prevents body temp decreasing when external temp decreases
- skin thermoreceptors stimulated
- impulse sent to hypothalamus
- vasoconstriction of arterioles to reduce heat loss
- prevents heat loss by convection
- increased metabolism to generate heat
- adrenaline released which causes shivering
describe anaerobic respiration in animals
- pyruvate converted to lactate
- pyruvate accepts H
- H from NADH
- catalysed by lactate dehydrogenase
- no O2 to act as final electron acceptor so no ETC
suggest how seals are adapted to respire for a long time underwater
- lungs have high vital capacity
- lower metabolic rate
- more glycolysis
- tolerates lactate
- plenty of Hb
why is ethanol considered a primary metabolite of yeast
ethanol produced by yeast as metabolic waste
