Biochem Exam 4

Front 1

Glycolysis

Back 1

2 NADH - generated in step 6 from glyceraldehyde3P to 1,3bisphosphate
2 pyruvate
2 ATP - 4 produced over all in step 7 and step 10.

Front 2

1st Regulated steps in Glycolysis

Back 2

step one - hexokinase
Glucose goes to G6P
hexokinase is inhibited by G6P, product inhibition
Hexokinase also has multiple isoenzymes A,B,C.
Hexokinase D is glucokinase and in not inhibited by G6P.

Front 3

2nd regulated step in Glycolysis

Back 3

Step 3:
regulated by PFK
this step commits the glucose to this pathway.
F6P goes to F1,6bisphos.

Allosteric enzyme:
Activated by ADP and F2,6bisp
Inhibited by ATP and PEP formed in step 9

Front 4

Last regulated step in glycolysis

Back 4

regulated by pyruvate kinase.
go from PEP to pyruvate and generate ATP.
inhibited by ATP.

Front 5

Amphibolic pathway

Back 5

pathways that participate in both anabolic and catabolic reactions

Front 6

anaplerotic reaction

Back 6

reactions that replinish CAC intermediates.

Front 7

Gluconeogenesis

Back 7

pyruvate to glucose
occur primarly in liver.
the reverse reaction of glycolysis.
The first step goes from PEP to pyruvate:
pyruvate catalyzed by pyruvate carboxylase to oxaloacetate.
pyrucate carboxlyase requires biotin to be active.
oxaloacetate is coverted to PEP carboyxkinase using GTP.
F1,6bisp goes to F6P via F1,6bisphopase.
inhibited by AMP F2,6bisp
activated by ATP
Last reaction is catalyzed by G6Pase goes from G6P to glucose.

Front 8

Gluconeogenesis requires how many ATP?

Back 8

6 ATP

Front 9

Glycogenolysis

Back 9

Glycogen to glucose
Involves 2 enzymes;
glycogen phosphoylase -
phosphorylase a is always active.
phosphoylase b has T/R form.
activated - AMP
inhibited - ATP, G6P
the active phosphoylase a is inhibited by glucose.
this enzyme adds a phosphate to a glucose in the glycogen chain.
2nd enzyme is debranching enzyme - cleaves alpha(1,4) and alpha(1,6) linkages.

Front 10

Glycogenesis

Back 10

synthesis of glycogen from glucose.
G1P is catalyzed to UDPG.
and 2 ATP are necessary to activate the glucose.
Requires glycogenin to start the chain of UDPG then glycogen synthase takes over and adds the UDGP to the growing glycogen molecule.
Branching enzyme takes 7 sugars at nonreducing end and mover them 4 sugars away and make a 1,6 branch point.

Front 11

Glycogen Synthase

Back 11

inactive D form and an active I form.
the inactive D form is phosphorlyated.
Therefore, glycogen synthase is inhibited by ATP and it is activated by G6P.