Lecture 31

Question 1

describe thermodynamic properties of atp

Answer 1

if add oxygen to anaerobic yeast = stops making glucose

Question 2

name the 3 rate controlling reactions

Answer 2

hexokinase
pfk
Pyruvate kinase steps
all have low ∆𝐺°’

Question 3

describe regulation of hexokinase

Answer 3

product inhibition - feedback inhibition
g6p = binding site on enzyme will decrease activity

Question 4

describe regulation of phosphofructokinase by adenylate charge

Answer 4

make sure no futile cycle - inhibited by f2 6bp and amp
high affinity form atp
adp bound to allosteric sites - only binds when atp levels high = can sense levels
atp can inhibit pfk
high atp = activity decrease, rigthward shift
affinity of pfk not as good when atp levels high

Question 5

describe regulation of phosphofructokinase by F2, 6 BP

Answer 5

PFK-2/FBPase-2 generates f26bp (from f6p) -
if no f26bp = activity worse
high = increase pfk activity

Question 6

describe regulation of pyruvate kinase

Answer 6

also inhibited by high adenylate charge and high fuel stores
atp, acetyl coa (made in mito, if build up from fatty acid ox), alanine