Pentose Phosphate Pathway

Question 1

what are the 2 goals of the PPP

Answer 1

to generate reducing powers (NADPH)
and to generate ribose

Question 2

what is the currency of reducing power for most reductive biosynthetic reactions

Answer 2

NADPH

Question 3

what does the PPP generate?

Answer 3

ribose 5 phosphate

Question 4

where are the reactions of the PPP carried out ?

Answer 4

in the cytosol

Question 5

describe the first phase of PPP

Answer 5

the oxidative phase, glucose gets oxidized and NADP+ gets reduced to NADPH. 3 enzymes, 2 NADPH generated

Question 6

describe the second phase of PPP

Answer 6

the non oxidative phase
ribulose 5 phosphate is converted to ribose 5 phosphate.
NO NADPH formed.
lots of interconversions of carbon happening

Question 7

does the cell require NADPH more or Ribose 5 phosphate

Answer 7

NADPH

Question 8

what happens to excess ribose 5 phosphate in PPP

Answer 8

it can go into glycolysis and be converted to intermediates by the enzymes Transaldolase and Transketolase

Question 9

what is the PPP primarily regulated by

Answer 9

levels of NADP+ in the cytosol

Question 10

which enzymes compete to bind to glucose 6 phosphate dehydrogenase

Answer 10

NADPH and NADP+

Question 11

if the need for NADPH is low, what happens in the PPP

Answer 11

pathway favours glycolysis

Question 12

where does the PPP occur (tissues?)

Answer 12

usually in the liver