2. Glycolysis and Gluconeogenesis

Question 1

what is the process on glycogenolysis

Answer 1

glycogen to glucose

Question 2

What is glycolysis

Answer 2

glucose to pyruvate

Question 3

what is glycogenesis

Answer 3

glucose to glycogen

Question 4

what is gluconeogenesis. and where does this only happen?

Answer 4

pyruvate to glucose

only occurs in the liver and kidneys

Question 5

what are the 2 forms of NAD+ and which type are they (OIL RIG)

Answer 5

NAD+ (oxidised)

NADH (reduced)

Question 6

Glycolysis

Answer 6

• Generation of ATP
• Generation of reduced coenzymes which can be used to form ATP
• Generation of energy independent of oxygen-
• Breakdown of glucose to precursors for fat and protein synthesis (acetyl-CoA)

Question 7

What is the role of hexokinase in glycolysis?

Answer 7

Glucose
to
Glucose-6-phosphate
by transferring phosphate from ATP

Question 8

What is the role of Phosphoglucose Isomerase in glycolysis?

Answer 8

Glucose-6-phosphate
to
Fructose-6-phosphate

Question 9

What is the role of phosphofructokinase in glycolysis?

Answer 9

Fructose-6-phosphate
to
Fructose-1,6-biphosphate by transferring a phosphate group from ATP

Question 10

What is the role of Aldolase in glycolysis?

Answer 10

Fructose-1,6-disphospahte
to 2 carbon molecules. One is gyceraldehyde-3-phospahte and the other 3C molecule =
Dihydroxyacetone-phosphate

Question 11

What is the role of Triose phosphate isomerase in glycolysis?

Answer 11

Converts dihydroxyacetone-phosphate into second molecule into glyceraldehyde-3-phosphate

Question 12

What is the role of Glyeraldehyde-3-phosphate dehydrogenase in glycolysis?

Answer 12

glyceraldehyde-3-phospahte
to
1,3-biphosphoglyerate

through the molecules gaining a phosphate group and being oxidised. 2 NADH and 2 H+ are formed in the process

Question 13

What is the role of phosphoglyeratekinase in glycolysis?

Answer 13

1,3-biphosphoglycerate
to
3-phosphoglycerate

the process transfers phosphates to ADP to form 2 molecules of ATP

Question 14

What is the role of phosphoglyceratemutase in glycolysis?

Answer 14

3-phosphoglycerate
to
2-phosphoglycerate

Question 15

What is the role of enolase in glycolysis?

Answer 15

2-phosphoglycerate
to
PEP (phosphoenolpyruvate)

Question 16

What is the role of Pyruvate kinase in glycolysis?

Answer 16

PEP (phosphoenolpyruvate)
to
Pyruvate

it mediate the transfer of phosphates from PEP to ADP forming 2 ATP molecules

Question 17

what are the 3 main sections of glycolysis and what is the main intermediates involved in each stage

Answer 17

1. Preparation = glucose –> fructose-1,6 bisphosphate
2. Splitting = fructose-1,6-bisphosphate –> 2 x 3 carbon compounds
3. Harvest = 3C compounds –> pyruvate

Question 18

At a slow metabolic rate NAD is not limiting. At a fast metabolic rate what happens?

Answer 18

NAD can become limiting. Here NADH is reversed back to NAD by creating lactate.

Question 19

What is the main control enzyme of glycolysis and how?

Answer 19

PFK —> phosphofructokinase

It is inhibited by lots of ATP and stimulated by ADP

Question 20

What are the steps of gluconeogenesis?

Answer 20

All the same steps of glycolysis but in reverse. stages 10, 3 and 1 are different however.

10. Pyruvate to oxaloacetate via pyruvate carboxylase. then Oxaloacetate to phosphoenolpyruvate via PEP carboxykinase
11. Fructose 1,6 bisphosphate to fructose 6 bisphosphate via fructose 1,6 bisphosphatase
12. Glucose 6 phosphate to glucose via glucose 6 phosphotase

Question 21

where does gluconeogenesis occur?

Answer 21

in the liver