PPP regulation

Question 1

two major prods

Answer 1

NADPH and R5P

Question 2

pathway regulation depends on

Answer 2

cellular needs whether its dividing, reducting biosynthesis, energy production.

Question 3

TA and TK

Answer 3

convert excess R5P into glycolytic intermediates: the whole point of the hats moving.

When dont need R5P for nucleotide synth but do need NADPH…. this is mode 2… this can be done by using PPP 6 times and a small part of GNG where we are converting 1 G6P into 6 CO2 and 12 NADPH….

Question 4

If need a large amount of R5P, can

Answer 4

can pull backwards from glycolysis. can take F6P and GAP, pull back to make R5P. This is exploited by cancer cells (no regulation)

Question 5

rate control

Answer 5

will be a rate control of the first step, so this is where regulation first comes into play.
Regulated by concentratio of NADP+ (rxn 1: hydride to NADP+, one of the substrates) so when NADPH is used up (fats, steroid hormones) and as a result will make more NADp+. So G6PDH adds more hydrides to make more NADPH. Which means G6PDH rate goes up, which means you have produced more NADPH to get used.