Carbs 4 Flashcards Preview

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Flashcards in Carbs 4 Deck (26):
1

Where does Gluconeogenesis occur ?

In the hepatocytes in the Liver

2

How many irreversible and reversible reactions are there in Glycolysis ?

Irreversible: 3
Reversible: 7

3

Where in the cell does Gluconeogenesis take place ?

In the cytosol & the mitochondria

4

How many bypass reactions are there in Gluconeogenesis ?

4 Bypass reactions

5

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

Pyruvate -> Oxaloacetate -> Malate

6

What are the enzymes that catalyze these reactions ?

Pyruvate -> Oxaloacetate = Pyruvate Carboxylase
Oxaloacetate -> Malate = Malate Dehydrogenase

7

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

Malate -> Oxaloacetate -> PEP

8

What enzymes catalyze these reactions ?

Malate -> Oxaloacetate = Malate Dehydrogenase
Oxaloacetate -> PEP = PEP Carboxylase

9

When Lactate is the substrate what occurs ?

Lactate -> Pyruvate via Lactate Dehydrogenase

10

What happens within the mitochondria when lactate is the substrate ?

Pyruvate -> Oxaloacetate ->PEP

11

What enzymes catalyze these reactions ?

Pyruvate -> Oxaloacetate = Pyruvate Carboxylase
Oxaloacetate -> PEP = PEP Carboxylase

12

What happens outside the mitochondria when lactate is the substrate ?

PEP leaves the mitochondria & this is the final step

13

What is the 3rd bypass reaction in Gluconeogenesis ?

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

14

What is the catalyst in the 3rd bypass reaction ?

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

15

What is the 4th bypass reaction in Gluconeogenesis ?

G-6-P -> Glucose

16

What is the catalyst in the 4th bypass reaction ?

G-6-P

17

How does the body metabolize Fructose & Galactose ?

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

18

How is Fructose broken down ?

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

19

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

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

20

How is Galactose broken down ?

Galactose -> G-1-P

21

What catalyses the breakdown of Galactose ?

UDP (Sugar nucleotide derivative)

22

What is the purpose of the pentose phosphate pathway ?

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

23

What is the starting substrate of the Pentose Phosphate pathway ?

G-6-P

24

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

Oxidative (irreversible) & Non-oxidative (reversible)

25

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

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

26

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

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