Biochemistry: glycolysis, TCA cycle & oxidative phosphorylation Flashcards
what are the products of aerobic glycolysis
2pyruvate + 4ATP + 2H20 + 2NADH + 2H+
what are the products of anaerobic glycolysis
lactic acid + 2ATP
how is glycolysis regulated at substrate level
by hexokinase( glucose to glucose-6-phosphate)
how is glycolysis regulated at rate level
by phosphofructokinase
how is glycolysis regulated at product exit level
by pyruvate kinase( inhibited by ATP)
how is glycolysis activated
by AMP and frucotse-2,6-biphosphate
when energy is needed
how is glycolysis inhibited
by ATP/citrate(excess energy), by H+(excess lactic acid)
where does TCA cycle take place
mitochondrial matrix
how does pyruvate enter matrix
via H+/pyruvate symporter
pyruvate is converted to what substance that goes into the TCA cycle, and by what enzyme
converted to acetyl CoA via pyruvate dehydrogenase complex
what are the products of the TCA cycle
2CO2, 3NADH+, H+, FADH2, ATP
what is one glucose molecule equivalent to in pyruvate
= 2 pyruvate( i.e. 2ATP)
how does NADH enter the matrix
via malate-aspartate shuttle
where are all enzymes found in the matrix, with one exception
ALL found in inner membrane of matrix, except succinate dehydrogenase
what is the TCA cycle inhibited by
ATP, NADH, acetyl-CoA( excess energy)
what is the TCA cycle activated by
ADP, NAD+( need energy)
what is redox potential
the electron transfer potential
describe the redox potential of NADH+/FADH2 and of O2/H2O
NADH+/FADH2 has -ve redox potential, tend to donate electrons( strong reducers)
O2/H2O has +ve redox potential( strong oxidisers)
describe how the electron transport chain works
electrons passed along chain, O2 is final acceptor( forms H2O)
this process produces energy, used to pump H+ across inner matrix
H+ flows back through ATP synthase to produce ATP
how much ATP is produced per glucose molecule by oxidative phosphorylation, and what does it depend on
30-32 ATP, depending on the phosphate/oxygen ratio
