Week 14: Gluconeogenesis

Question 1

What is gluconeogenesis?

Answer 1

Synthesis of glucose within the body from non-carbohydrate precursors
i.e ran out of glycogen

Question 2

When does gluconeogenesis occur?

Answer 2

prolonged starvation, new glucose has to be synthesized

Question 3

What are precursors for gluconeogenesis?

Answer 3

lactate
amino acids
glycerol

Question 4

Where does the energy come from in gluconeogenesis?

Answer 4

oxidation of fatty acids released from adipose tissue

from the liver & kidneys

Question 5

How many enzymes are needed in gluconeogenesis?

Answer 5

4 from liver

Question 6

What is the intermediate compound in gluconeogenesis?

Answer 6

oxaloacetate in mitochondria

Question 7

What is a anaplerotic reaction?

Answer 7

important for accepting acetyl groups from fat breakdown

Question 8

Is gluconeogensis energy consuming?

Answer 8

YES only use when really need

Question 9

What are the 4 enzymes used in gluconeogenesis?

Answer 9

glucose-6-phosphotase
fructose-1,6 bisphosphotase
Pyruvate carboxylate
PEP carboxylkinase

Question 10

How much ATP is invested?

Answer 10

6ATP plus 2x NADH (5ATP)

for 1 molecule glucose

Question 11

What is the process called that converts lactate to glucose?

Answer 11

Cori cycle

Question 12

When is lactate formed?

Answer 12

formed in fast-twitch muscle under conditions of heavy exercise

Question 13

What transports lactate to liver?

Answer 13

blood

Question 14

What does the liver do to lactate?

Answer 14

Liver converts lactate back to glucose into bloodstream

Question 15

What are amino acid precursors that can directly drive the formation of glucose called?

Answer 15

glycogenic amino acids

Question 16

What are amino acids called that don’ directly drive formation of glucose?

Answer 16

ketogenic amino acids

form ketone bodies, breakdown of fat, relate to fat metabolism

Question 17

What does level of glucose 6 phosphate mean?

Answer 17

high in fed state

low in starved state

Question 18

What does presence of citrate, alanine & acetyl-CoA mean?

Answer 18

high when intermediates or building blocks are abundant

Question 19

What does glucagon positively regulate?

Answer 19

fructose-1,6 bisphosphatase

Question 20

What does glucagon negatively regulate?

Answer 20

FFK

Question 21

What does insulin positively regulate?

Answer 21

FFK, breakdown glucose whilst we have plenty of it

Question 22

What does insulin negatively regulate?

Answer 22

fructose-1,6 bis-phosphatase

Question 23

What does fructose-1,6 biohosphatase enzyme convert?

Answer 23

converts fructose-1,6 bis-phosphate to fructose-6 phosphate (gluconeogenesis- pyruvate to glucose)

Question 24

What does FFK enzyme convert?

Answer 24

converts fructose-6 phosphate to fructose-1,6 biphosphate (glycolysis- glucose to pyruvate)