Gluconeogenesis

Question 1

What are the three enzymes that need bypassing in gluconeogenesis?

Answer 1

Pyruvate kinase,
PFK-1
and Glucokinase

Question 2

How is glucokinase bypassed in gluconeogenesis?

Answer 2

glucose 6- phosphatase

Question 3

How is pyruvate kinase bypassed in gluconeogenesis?

Answer 3

Phosphoenolpyruvate Carboxykinase (PEPCK)

Pyruvate must be transformed to Acteyl-CoA first before going back to PEP (by pryuvate dehydrogenase rxn)

Acteyl-CoA goes to oxaloaceatate–>malate back to oxaloacetate–> phosphoenolpyruvate (PEP)

Question 4

How is PFK-1 bypassed in gluconeogenesis?

Answer 4

F-1,6 bisphosphatase

Question 5

Glucagon inhibits glycolysis by? (by decreasing ___ and by phosphorylating ____?)

Answer 5

decreasing fructose-2,6 bisphosphate

and phosphorylating PK (which deactivates PK)

Question 6

With type two diabetes (aka insulin resistance), insulin fails to inhibit _____?

Answer 6

gluconeogenesis, results in excess blood glucose levels

Question 7

alanine inhibits what enzyme during gluconeogenesis?

Answer 7

pyruvate kinase

Question 8

what are enzymes of non hormonal regulators of hepatic gluconeogenesis?

Answer 8

glucose 6 phosphatase

fructose 1,6 bisphophatase

phosphoenolpyruvate carboxykinase (PEPCK)

pyruvate carboxylase

Question 9

what is the non-hormonal regulator that is unique to gluconeogenesis? what does it activate?

Answer 9

acteyl-CoA, which activates pyruvate carboxylase

Question 10

what is fructose 1,6 bisphosphatase inhibited by? (2 things)

Answer 10

AMP

And fructose 2,6 bisphosphate

Question 11

the two pathways are _____ regulated in the liver to avoid a futile cycle.

Answer 11

reciprocally

Question 12

what else can become pyruvate?

Answer 12

lactate
alanine 
cystein
glycine 
serine 
trypotophan

Question 13

glycerol is a ____ substrate

Answer 13

glucogenic

Question 14

Can you get glucose form fatty acids?

what can you get glucose from?

Answer 14

no.

amino acids, ketones (from fats)

Question 15

can lipolysis increase glucose production?

Answer 15

yes, can cleave glyerol to be used

need two glyerols / 1 glucose

Question 16

what is used first for glucose production?

Answer 16

amino acids, then fat can make ketones

Question 17

how many ATPs are produced during anaerobic glycolysis?

When/where would this occur?

Answer 17

2 ATPS

RBCs
in vigorously working muscles,
with ischemia (stroke/hear attack=loss of blood flow)
and in tumors

Question 18

what is formed with anaerobic glycolysis?

Answer 18

two lactate (from pyruvate )

Question 19

how can lactate be used?

Answer 19

• by muscle that created it
• by sending it to heart/resting muscle to form ATP
• by liver, to convert back to pyruvate and generate glucose

Question 20

What is the Cori cycle?

Answer 20

the catabolism of glucose to lactate in peripheral tissues, then anabolism of lactate to glucose in the liver.