Gluconeogenesis

Question 1

Glucose

Answer 1

Synthesized for energy in liver, kidneys
Used by muscles, erythrocytes, brain, etc
Stable, transportable forms of carbohydrates
Glucose polymers used for storage (glycogen, starch) or synthesis of cellular matrices (cellulose)

Question 2

Gluconeogenesis

Answer 2

2 pyruvate + 4 ATP + 2 GTP + 2 NADH + 2H + 4H2O–>glucose +4 ADP + 2 GDP + 6 Pi + 2 NAD+
Requires 4 ATP 2 GTP and 2 NADH
Synthesize glucose from non-carbohydrate precursors
Convert pyruvate (and lactate and glycerol) into glucose
Occurs mostly in liver
3 steps different from glycolysis (all regulatory steps)
Must overcome highly exergonic rxns here
Requires Acetyl-CoA as effector to start

Question 3

Bypass of pyruvate kinase

Answer 3

Pyruvate–>oxaloacetate–>malate–>oxaloacetate–>PEP
Requires 2 enzymes:
a) pyruvate carboxylase
b) PEP carboxykinase
Oxaloacetate must be transformed into malate to exit mitochondria if pyruvate is precursor
NADH must be available

Question 4

Acetyl Co-A

Answer 4

SIgnals accumulation of fatty acids as fuel

Produced by fatty acid oxidatio

Question 5

Lactate

Answer 5

Conversion of lactate–>PEP does not require malate dehydrogenase bc NADH is synthesized from
lactate–>pyruvate

Question 6

pyruvate carboxylase

Answer 6

pyruvate–>oxaloacetate
occur in mitochondria
stimulated by acetyl co-a

Question 7

PEP carboxykinase

Answer 7

pyruvate–>oxaloacetate

Question 8

Bypass of PFK

Answer 8

FBPase-1

F 1,6 BP–> F6P

Question 9

Bypass of hexokinase

Answer 9

Just requires water