anaerobic respiration Flashcards
what cant happen if oxygen isnt present in the mitochondria
oxygen cant act as the final electron accepter after oxidative phosphorylation, no water is formed
oxidative phosphorylation cant occur
reduced nad and fad cant release their hydrogen ions and become reoxidised.
what are the two metabolic pathways used to respire without oxygen, and what organisms use them
ethanol fermentation- fungi/ plants
lactate fermentation- mammals
what occurs in the ethanol fermentation pathway
pyruvate is decarboxylated to produce 1co2 and ethanal, catalysed by the enzyme pyruvate decarboxylase.
ethanal accepts two hydrogen from reduced nad, to produce ethanol and NAD, catalysed by ethanol dehydrogenase
what are the two enzymes used in ethanol fermentation
pyruvate decarboxylase
ethanol dehydrogenase
where does lactate fermentation take place
takes place in mammalian muscle tissue during vigorous activity
in what conditions does lactate fermentation occur
when there is a demand for ATP for muscle contraction and there is an oxygen deficit
what occurs during lactate fermentation
pyruvate from glycolysis accepts hydrogen from reduced nad to produce lactate. catalysed by lactate dehydrogenase
what enzyme catalyses lactate fermentation
lactate dehydrogenase
what happens with lactate when it is produced
lactate is produced in muscles and carried from blood to liver to be converted to pyruvate, which can enter krebs cycle from link reaction.
how does lactate and ethanol fermentation allow glycolysis to continue
they reoxidise NAD so they can accept hydrogen atoms from triose phosphate during glycolysis, so it can continue to produce their net gain of 2 atp.
how does the yield of atp from anaerobic respiration differ to the yield produced from aerobic respiration
the anaerobic yield is about 1/15 of that produced by aerobic respiration
why does anaerobic respiration produce less atp per molecule of glucose?
because NAD is not regenerated in oxidative phosphorylation
