Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOC192 2024 > Lecture 24 > Flashcards

Lecture 24 Flashcards

1
Q

What is glyolysis?

A

The splitting of glucose molecules to form pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does glycolysis provide?

A

The net gain of 2ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two stages of glycolysis?

A

Energy investment and energy payoff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is energy investment?

A

Spending 2ATP to add 2 phosphates onto glucose in two stages - activation of glucose (x2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is activation of glucose?

A

Getting the molecule into a form so energy can be captured, adding phosphates (x2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Is the activation of glucose energetically favourable or unfavourable?

A

Energetically unfavourable, +ve gibbs energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can an energetically unfavourable reaction made favourable?

A

By reaction coupling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the activation of glucose coupled with?

A

ATP hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What enzyme couples the activation of glucose and ATP hydrolysis reactions

A

Hexokinase first and phosphofructokinase second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the glucose first converted into - first activation of glucose?

A

Glucose-6-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What enzyme catalyses the rearrangement of glucose-6-phosphate?

A

Glucosephosphate isomerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is glucose-6-phosphate rearranged into?

A

Fructose-6-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Is the conversion of G-6-P to F-6-P energetically favourable or unfavourable?

A

Energetically unfavourable, however, because it is in the middle of the pathway, it is driven forward to completion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What enzyme catalyses the seconds activation of glucose?

A

Phosphofructokinase, coupling with ATP hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the seconds activation of glucose form?

A

Fructose-1,6-bisphosphate (FBP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens at the end of the energy investment phase?

A

The aldolase reaction: FBP is split into dihydroxyacetone phosphate and glyceraldehyde-3-phosphate (G-3-P) (2x 3C molecules w/ 1P each)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What enzyme catalyses the aldolase reaction?

A

Aldolase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to dihydroxyacetone phosphate?

A

It is rearranged to glyceraldehyde-3-phosphate by triose phosphate isomerase enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two key reactions for ATP synthesis?

A

ATP synthesis and redox reactions using coenzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the reaction of ATP synthesis?

A

ADP + Pi -> ATP

21
Q

What type of phosphorylation is ATP synthesis?

A

Substrate-level phosphorylation, direct. Energy comes straight from substrate

22
Q

What type of phosphorylation is a redox reaction?

A

Oxidative phosphorylation, indirect through reduced co-enzymes

23
Q

What is substrate-level phosphorylation

A

The direct use of energy from a substrate molecule to drive the synthesis of ATP

24
Q

How is energy released through substrate-level phosphorylation?

A

Through cleaving a high energy phosphate bond

25
Q

What is the problem with SLP and net energy gain?

A

1 ATP must be spent to create the phosphate bond and 1ATP is made when the bond is cleaved, no net energy gain

26
Q

How is the problem of net energy gain fixed?

A

Through redox reactions using coenzymes

27
Q

What is a redox reaction?

A

Fuel molecules get oxidised a co enzyme gets reduced

28
Q

What are the key coenzymes?

A

NAD and FAD

29
Q

What is NAD?

A

Nicotinamide adenine dinucleotide, derived from niacin (V-B3)

30
Q

What does NAD undergo?

A

A two-electron reduction

31
Q

What is a reducing equivalent?

A

H atom with 2H+ and 2e-

32
Q

What is the first key reaction for making ATP profit?

A

G-3-P is oxidised by the oxidising power of NAD+ which is reduced to NADH. This forms 1,3-Bisphosoglycerate (1,3-BPG). A phosphate has been added without ATP.

33
Q

What enzyme catalyses the reaction from G-3-P to 1,3,-BPG?

A

Glyceraldehyde-3-phosphate dehydrogenase

34
Q

What is the second key reaction for making ATP profit?

A

1,3-BPG undergoes the first substrate-level phosphorylation generating an ATP. This forms 3-phosphoglycerate (3PG)

35
Q

What enzyme catalyses 1,3-BPG to 3PG?

A

Phosphoglycerate kinase

36
Q

Why is 3PG rearranged?

A

To get the molecule into a form that enables the following reactions to occur

37
Q

What is 3PG rearranged to?

A

2PG by Posphoglyceromutase
Phosphoenolpyruvate (PEP) by enolase

38
Q

What does the second substrate level phosphorylation provide?

A

Pyruvate from PEP using pyruvate kinase and an ATP molecule

39
Q

What is the overall reaction for glycolysis?

A

Glucose + 2NAD+ + 2ADP + 2Pi -> 2 pyruvate + 2NADH + 2ATP + 2H+

40
Q

What is arsenic poisioning of glycolysis?

A

Arsenate (AsO4³⁻) replaces phosphate (PO4³⁻) in the reaction from G-3-P, forming 1-arseno-3-phosphoglycerate instead of 1,3-BPG. This releases energy as heat instead of producing ATP (no net loss or gain)

41
Q

What are the fates of pyruvate?

A

Aerobic oxidation and anaerobic glycolysis

42
Q

What is an aerobic reaction?

A

One with plentyful oxygen

43
Q

What is an anaerobic reaction?

A

One with limited/low oxygen

44
Q

What occurs during aerobic oxidation of pyruvate?

A

Pyruvate undergoes pyruvate dehydrogenation into acetyl in the mitochondrial matrix which is then bound to CoA to further be metabolized in the CAC.

45
Q

What is the net reaction of aerobic oxidation of pyruvate?

A

Oxidative decarboxylation where CO2 is released (3C -> 2C) and pyruvate is oxidised and energy is captured in the form of NADH which is then used to bind acetyl to coenzyme A

46
Q

What is CoA?

A

Coenzyme A (CoA) is derived from pantothenic acid (vitamin B5) and is not a carrier of electrons, therefore cannot preform a redox reaction.

47
Q

What are the two forms of CoA?

A

Free coenzyme A: CoASH and Acyl group attached: Acyl-CoA

48
Q

What happens in anareobic glycolysis of pyruvate?

A

Pyruvate is converted to lactate and energy captured in NADH is lost to lactate which regenerates NAD+. Lactate causes muscle fatigue. After this, glycolysis can continue to generate ATP

49
Q

Where does anaerobic glycolysis of pyruvate occur?

A

In the red blood cells and muscle

BIOC192 2024 (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions