Carbs 4

Question 1

Where does Gluconeogenesis occur ?

Answer 1

In the hepatocytes in the Liver

Question 2

How many irreversible and reversible reactions are there in Glycolysis ?

Answer 2

Irreversible: 3
Reversible: 7

Question 3

Where in the cell does Gluconeogenesis take place ?

Answer 3

In the cytosol & the mitochondria

Question 4

How many bypass reactions are there in Gluconeogenesis ?

Answer 4

4 Bypass reactions

Question 5

What does Pyruvate turn into within the mitochondria in the first bypass reaction of Gluconeogenesis ?

Answer 5

Pyruvate -> Oxaloacetate -> Malate

Question 6

What are the enzymes that catalyze these reactions ?

Answer 6

Pyruvate -> Oxaloacetate = Pyruvate Carboxylase

Oxaloacetate -> Malate = Malate Dehydrogenase

Question 7

Once Malate has left the mitochondria what does Malate turn into ?

Answer 7

Malate -> Oxaloacetate -> PEP

Question 8

What enzymes catalyze these reactions ?

Answer 8

Malate -> Oxaloacetate = Malate Dehydrogenase

Oxaloacetate -> PEP = PEP Carboxylase

Question 9

When Lactate is the substrate what occurs ?

Answer 9

Lactate -> Pyruvate via Lactate Dehydrogenase

Question 10

What happens within the mitochondria when lactate is the substrate ?

Answer 10

Pyruvate -> Oxaloacetate ->PEP

Question 11

What enzymes catalyze these reactions ?

Answer 11

Pyruvate -> Oxaloacetate = Pyruvate Carboxylase

Oxaloacetate -> PEP = PEP Carboxylase

Question 12

What happens outside the mitochondria when lactate is the substrate ?

Answer 12

PEP leaves the mitochondria & this is the final step

Question 13

What is the 3rd bypass reaction in Gluconeogenesis ?

Answer 13

Fructose-1,6-Bisphosphate -> F-6-P

Question 14

What is the catalyst in the 3rd bypass reaction ?

Answer 14

F-1,6-P is the catalyst in this reaction

Question 15

What is the 4th bypass reaction in Gluconeogenesis ?

Answer 15

G-6-P -> Glucose

Question 16

What is the catalyst in the 4th bypass reaction ?

Answer 16

G-6-P

Question 17

How does the body metabolize Fructose & Galactose ?

Answer 17

The body does not have a specific pathway for these carbohydrates, they can enter glycolysis at any point.

Question 18

How is Fructose broken down ?

Answer 18

Fructose -> F-1-P -> Glyceraldehyde + Dihydroxyacetone phosphate -> Glyceraldehyde -3- P

Question 19

What enzymes catalyze the breakdown of Fructose into Glyceraldehyde-3-P ?

Answer 19

Fructose -> F-1-P = Fructokinase
F-1-P -> Glyceraldehyde = F-1-P Adolase
Glyceraldehyde -> Glyceraldehyde-3-P = Triose Kinase

Question 20

How is Galactose broken down ?

Answer 20

Galactose -> G-1-P

Question 21

What catalyses the breakdown of Galactose ?

Answer 21

UDP (Sugar nucleotide derivative)

Question 22

What is the purpose of the pentose phosphate pathway ?

Answer 22

Production of NADPH for all organisms & produces pentoses for synthesis of RNA & DNA

Question 23

What is the starting substrate of the Pentose Phosphate pathway ?

Answer 23

G-6-P

Question 24

What are the two phases in the pentose phosphate pathway & which is reversible & irreversible ?

Answer 24

Oxidative (irreversible) & Non-oxidative (reversible)

Question 25

What does the Oxidative phase of the Pentose Phosphate pathway consist of ?

Answer 25

G-6-P -> 6-Phosphogluconate -> Ribulose -5-Phosphate ->Ribose-5-Phosphate -> Nucleotides,RNA,DNA & Co-enzymes

Question 26

What does the on-oxidative phase of the Pentose Phosphate pathway consist of ?

Answer 26

G-6-P -> 6-Phosphogluconate -> Ribulose -5-Phosphate