Brainscape's Knowledge GenomeTM

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


See full index

Bioc 2580 > Oxidation of Glucose > Flashcards

Oxidation of Glucose Flashcards

1
Q

What are the 3 stages of glucose oxidation

A
  1. glycolysis + pyruvate dehydrogenase
  2. TCA cycle
  3. ETC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Can glucose enter cells via passive diffusion

A

no

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

What transporters are required to move glucose across the membrane

A

GLUTs (glucose transporters)
- reside in the cell membrane

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

What in the body stimulates GLUT mediated glucose uptake in skeletal muscle and adipose tissue

A

insulin

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

In diabetes, why does the body “starve in the midst of plenty”

A

because there is glucose to be taken up, but insulin cannot perform that action properly

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

What cell types are entirely dependant on glycolysis for energy provision

A

red blood cells, renal medulla, brain, and sperm

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

Glycolysis is the only pathway that can provide energy under ______________ conditions

A

anaerobic

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

Where does glycolysis occur

A

in the cytosol

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

How many steps are in glycolysis

A

10

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

What are the first 5 steps of glycolysis called

A

the preparatory phase

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

What are the last 5 steps of glycolysis called

A

the pay off phase

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

What is step 1 of glycolysis

A

phosphorylation of glucose
- ATP is used to phosphorylate glucose (adds a phosphate)

results in glucose-6-phosphate

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

What enzyme is used in step 1 of glycolysis

A

hexokinase

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

How many isozymes of hexokinase are there

A

4 (4 different enzymes that can equally effectively catalyze the same reaction)

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

What is step 2 of glycolysis

A

phosphohexose isomerization
- glucose is changed from a hexose to a pentose ring

results in fructose-6-phosphate

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

What enzyme and cofactor is used in the second step of glycolysis

A

phosphohexose isomerase
- cofactor is Mg2+

17
Q

What is step 3 of glycolysis

A

the second phosphorylation
- a phosphate is added to carbon 1 of fructose-6-phosphate

results in fructose 1,6-bisphosphate
(a bisphosphate has 2 phosphates in different locations, whereas a diphosphate has 2 phosphates connected to one another)

18
Q

What enzyme is used in the third step of glycolysis

A

phosphofructokinase-1 (PFK-1)

19
Q

What is step 4 of glycolysis

A

the six carbon fructose is split into two 3 carbon units
- fructose 1,6-bisphosphate is split into two separate 3 carbon molecules

results in dihydroxyacetone phosphate and glyceraldehyde 3-phosphate

20
Q

What enzyme is used in step 4 of glycolysis

A

aldolase

21
Q

What is step 5 of glycolysis

A

interconversion of the triose phosphates
- dehydroxyacetone phosphate is isomerized into glyceraldehyde 3-phosphate

results in now two glyceraldehyde 3-phosphate molecules

22
Q

What enzyme is required in step 5 of glycolysis

A

triose phosphate isomerase

23
Q

The mechanism of triose phosphate isomerase is essentially the same as ________________ _____________

A

phosphohexose isomerase

24
Q

What is step 6 of glycolysis

A

glyceraldehyde 3-phosphate dehydrogenase
the energy key to glycolysis
- glyceraldehyde 3-phosphate is phosphorylated at carbons 1 and 3

*results in 1,3 bisphosphoglycerate

25
Q

What enzyme is used in step 6 of glycolysis and what cofactor is needed

A

glyceraldehyde 3-phosphate dehydrogenase
- NAD+ is the cofactor

26
Q

What bond is created in step 6 of glycolysis between carbon 1 and the phosphate

A

a mixed anhydride bond - very high energy
why this step is called the energy key to glycolysis

27
Q

What is step 7 of glycolysis

A

phosphoryl transfer from 1,3-BPG to ADP
the first substrate level phosphorylation
- 1,3-bisphosphoglycerate is phosphorylated by ADP

*results in 3-phosphoglycerate and ATP formed

28
Q

What enzyme is used in step 7 of glycolysis and what cofactor

A

phosphoglycerate kinase
ADP is the cofactor

29
Q

How many ATP generated per GLUCOSE based on step 7 of glycolysis

A

1 glucose = 2 moles of 1,3-BPG (remember the double formation of G3P earlier) so that means 2 ATP per 1 glucose

30
Q

What is step 8 of glycolysis

A

conversion of 3-phosphoglycerate to 2-phosphoglycerate
- transfer of phosphate from carbon 3 to carbon 2 via a mutase enzyme (sub-class of isomerase)

*results in 2-phosphoglycerate

31
Q

What enzyme is used in step 8 of glycolysis

A

phosphoglycerate mutase

32
Q

What is step 9 of glycolysis

A

dehydration of 2-phospoglycerate
- water is removed (removal of a hydroxyl)

results in phosphoenolpyruvate

33
Q

What enzyme is required in step 9 of glycolysis

A

enolase

34
Q

What is step 10 of glycolysis

A

transfer of the phosphoryl group from phosphoenolpyruvate to ADP
the second substrate level phosphorylation
- the phosphate on carbon 2 is removed by ADP

results in enolpyruvate which is quickly tautomerized to ketopyruvate

35
Q

What enzyme is required in step 10 of glycolysis and what cofactor

A

pyruvate kinase
cofactor is ADP

36
Q

How many substrate level phosphorylations are seen in glycolysis

A

2

37
Q

What is the predominant form of pyruvate

A

keto form

38
Q

Why is pyruvate found in keto form

A

lowers the concentration of reaction product and pulls the reaction toward completion, resulting in a large negative delta G

Bioc 2580 (16 decks)

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