Glycolysis

Question 1

Definition of glycolysis:

Answer 1

Breakdown of glucose into smaller molecules

Produce ATP

Question 2

Where does glycolysis take place?

Answer 2

Cytoplasm of cells

Question 3

What ring does glucose form?

Answer 3

6 member Pyranose ring

Question 4

What ring does fructose form?

Answer 4

5 members furanose ring

Question 5

Structure of amino acid:

Answer 5

Amino group and carboxyl group

Question 6

What happens when two amino acids Bon?

Answer 6

Peptide bond formed between amino group on one and carboxyl group on the other

Question 7

What is an amino acid called with a carbonyl group?

Answer 7

Keto acids

Question 8

What are keto acids common in?

Answer 8

Metabolism - important for transamination

Question 9

What essentially is converted in glycolysis?

Answer 9

Glucose converted to pyruvate

Question 10

What is glucose first converted to?

Answer 10

Glucose-6-Phosphate

Phosphorylation

Question 11

What happens in first phophorylation of glucose?

Answer 11

ATP consumed

Hexokinase traps glucose in cell because glucose-6-P is ionised

Question 12

Significance of glucose-6-P being ionised:

Answer 12

Unable to cross cell membrane

Question 13

What happens after phosphorylation go glucose into glucose-6-P?

Answer 13

Isomerisation of Glucose-6-P into fructose-6-P

Question 14

What happens in isomerisation of glucose—P into fructose-6-P?

Answer 14

Pyranose ring -> fruranose ring

Question 15

What is fructose-6-P then converted into?

Answer 15

Fructose 1,6 -biphosphate

Phosphorylation

Costumes ATP

Enzyme phosphofructokinase

Question 16

What is fructose-1,6 -biphosphate further split into?

Answer 16

2x glyceraldehyde-3-phosphate

Question 17

Process of forming 2x glyceraldehyde-3-P:

Answer 17

Cleavage and isomerization

Forms dihydroxyacetone which is then converted into 1x glyceraldehyde-3-P

Question 18

What happens to glyceraldehyde-3-P?

Answer 18

Simultaneously oxidised and phosphorylated by oxidative phosphorylation

Forms 1,3 - Biphosphoglycerate

Question 19

What happens in oxidative phosphorylation of glyceraldehyde 3-P?

Answer 19

H+ and 2e- passed to NAD+ to form NADH

Phosphate is also added to each glyceraldehyde 3-P

Question 20

What is NAD+?

Answer 20

Co-factor

Collects hydrogen and electrons

Question 21

What’s NAD+ made of?

Answer 21

Nicotinamide

Ribose

Adenosine

Question 22

What’s the reactive site of NAD+?

Answer 22

Nicorinamide = head group

Question 23

What does NAD+ stand for?

Answer 23

Nicotinamide adenine dinucleotide

Question 24

What provides nicotinamide part of NAD+?

Answer 24

Vitamin B3

Question 25

Lack of niacin:

Answer 25

Pellagra - sensitivity to sunlight

Question 26

NAD+ into NADH:

Answer 26

NAD+ + H+ + 2e- ——> NADH

Question 27

What then happens to 2x 1,3-Biphophoglycerate?

Answer 27

Phosphate transferred to ADP to produce ATP (2xATP per 1 molecule glucose) 3-phosphogylerate is produced

Question 28

What then happens to 3-Phosphoglycerate?

Answer 28

Molecular rearrangement of phosphate group - isomerisation 2-Phosphoglycerate formed

Question 29

What then happens to 2-phosphoglycerate?

Answer 29

Dehydration Water produced Forms phosphoenol pyruvate

Question 30

What then happens to 2x phosphoenol pyruvate?

Answer 30

Phosphate is transferred to ADP to produce ATP (2xATP produced per 1 molecule glucose) 2x Pyruvate formed Enzyme pyruvate kinase

Question 31

Net ATP produced in glycolysis:

Answer 31

2

Question 32

How is NAD+ regenerated under aerobic conditions?

Answer 32

NADH passes electrons and H+ (from glyceraldehyde-3-P) through electron transfer chain system Electrons and H+ combine with oxygen to produce water

Question 33

What else does electron transfer chain generate?

Answer 33

ATP

Question 34

What happens in absence of oxygen (anaerobic)?

Answer 34

NADH builds up as NAD+ can’t be regenerated Could stop glycolysis continuing

Question 35

Anaerobic conditions: what must be done to regenerate NAD+?

Answer 35

NADH re-oxidised Pyruvate is reduced lactate

Question 36

How is pyruvate reduced to lactate?

Answer 36

Pyruvate + NADH + H+ ———> Lactate + NAD+

Question 37

What enzyme converts pyruvate to lactate?

Answer 37

Lactate dehydrogenase

Question 38

How does yeast overcome problem of anaerobic conditions?

Answer 38

Converts pyruvate to ethanol

Question 39

Important enzymes in glycolysis:

Answer 39

Hexokinase Phosphofructokinase Pyruvate kinase

Question 40

What inhibits phosphofructokinase?

Answer 40

High ATP concentration Low pH High citric acid concentration

Question 41

What stimulates phosphofructokinase?

Answer 41

High fructose-6-P concentration