Glycolysis and Gluconeogenesis

Question 1

Location of glycolysis

Answer 1

Cytoplasm

Question 2

Where fermentation can happen

Answer 2

Outside of cell as well as inside

Question 3

Alpha-amylases

Answer 3

Enzymes that break down starch and glycogen at alpha-1,4 bonds to make di- and trisaccharides maltose and maltotriose

Question 4

Only non-starvation fuel used by brain and only fuel used by red cells at all

Answer 4

Glucose

Question 5

10 steps of glycolysis

Answer 5

Glucose -> glucose 6-phosphate -> fructose 6-phosphate -> fructose 1,6-bisphosphate -> glyceraldehyde 3-phosphate -> 1,3-bisphosphoglycerate -> 3-phosphoglycerate -> 2-phosphoglycerate -> phosphoenolpyruvate -> pyruvate

Question 6

Purpose of turning glucose into glucose 6-phosphate

Answer 6

Trap glucose in cell and destabilize it

Question 7

Hexokinase

Answer 7

Enzyme that adds phosphate to glucose in 1st step in glycolysis
Is regulated

Question 8

Phosphofructokinase

Answer 8

Enzyme that adds phosphate to fructose 6-phosphate in step 3 of glycolysis
Most regulated enzyme in glycolysis: committed step (glucose 6-phosphate can be stored and used by the body, whereas fructose 1,6-bisphosphate cannot)

Question 9

Bisphosphate vs. diphosphate

Answer 9

Bis: 2 separate monophosphoryl groups
Di: 2 monophosphoryl groups linked together

Question 10

Reason why isomerization of glucose to fructose occurs

Answer 10

Isomerization of glucose to fructose enables equal split of molecule into two 3-carbon compounds -> less enzymes needed

Question 11

Products of cleavage of fructose 1,6-bisphosphate

Answer 11

1 molecule of fructose 1,6-bisphosphate yields 2 molecules of glyceraldehyde 3-phosphate

Question 12

Mutase

Answer 12

Enzyme that swaps parts out by holding one of the parts

Ex- 3-phosphoglycerate to 2-phosphoglycerate: phosphate on 3-phosphoglycerate is removed and a new one is put on

Question 13

Net reaction of glycolysis

Answer 13

Glucose + 2 Pi (phosphates) + 2 ADP + 2 NAD+ -> 2 pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O

Question 14

Purpose of fermentation

Answer 14

Regeneration of electron carriers (NAD+) used up in glycolysis

Question 15

3 irreversible steps of glycolysis/ 3 steps bypassed in gluconeogenesis

Answer 15

1. Hexokinase turning glucose into glucose 6-phosphate
2. Phosphofructokinase turning fructose 6-phosphate into fructose 1,6-bisphosphate
3. Pyruvate kinase turning phosphoenolpyruvate into pyruvate

Question 16

The one molecule created in gluconeogenesis that isn’t found in glycolysis

Answer 16

Oxaloacetate

Question 17

Extra step added in gluconeogenesis

Answer 17

Pyruvate -> oxaloacetate -> phosphoenolpyruvate

ATP and GTP added to make phosphoenolpyruvate are all that is needed energywise to get back to glucose

Question 18

Net reaction of gluconeogenesis

Answer 18

2 pyruvate + 4 ATP + 2 GTP + 2 NADH + 6 H2O -> glucose + 4 ADP + 2 GDP + 6 Pi (phosphates) + 2 NAD+ + 2 H+