Brainscape's Knowledge GenomeTM

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


See full index

MEH > Glycolysis > Flashcards

Glycolysis Flashcards

1
Q

how are carbohydrates broken down

A
  1. amylase in the salvia and pancreas

2. disaccharidases break down disaccharides in the small intestine

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

what are dextrins

A

smaller subunits of carbohydrates

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

name 4 disaccahridases

A

lactase, sucrase, pancreatic amylase, isomaltase

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

what is lactose intolerance

A

when you don’t have the enzyme lactase so cant break down lactose

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

what is primary lactase deficiency

A

absence of the lactase allele. Only occurs in adults

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

why is primary lactase deficiency only seen in adults

A

as children are born with lactase to break down breast milk, but they may not carry on expressing this gene into adult life

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

what is secondary lactase deficiency

A

deficiency caused by damage to the small intestine. Occurs in both adults and children

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

true or false: secondary lactase deficiency is reversible

A

true

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

what is congenital lactase deficiency

A

an extremely rare recessive defect in the lactase gene.

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

what are the symptoms of lactose intolerance

A

bloating, flatulence, diarrhoea, vomiting, rumbling stomach

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

how are monosaccharides absorbed into the intestinal epithelia cells

A

active transport by sodium dependant glucose transporter 1 (SGLT1)

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

which transporter do monosaccharides go through to enter the blood

A

GLUT2

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

how do monosaccharides enter cells from the blood

A

facilitated diffusion using GLUT1-GLUT5 transport proteins

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

where are GLUT 2 proteins found

A

kidney, liver, pancreatic beta cells, small intestine

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

where are GLUT 4 proteins found

A

adipose tissue, striated muscle

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

which cells have an absolute requirement of glucose (4)

A
  1. RBC- no mitochondria so can only get energy from glycolysis no other sources
  2. Neutrophils- use their mitochondria to produce free radicals so cant be used in energy production
  3. Kidney Medulla - cortex require lots of oxygen so little reaches medulla
  4. lens of the eye - no capillaries so no oxidative phosphorylation so relies on glycolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does the uptake of glucose depend on

A

blood glucose concentration

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

what is stage 2 of energy release from carbohydrates

A

glycolysis

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

what occurs in phase 1 of glycolysis

A

2 ATP are used (investment)

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

why is phase 2 of glycolysis called the payback phase

A

4 ATP are produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the net production of glycolysis from 1 molecule of glucose

A

2 NADH, 4 ATP, 2 Pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

true or false: glycolysis is exergonic

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does hexokinase catalyse

A

conversion of glucose to glucose-6-Phosphate using energy from ATP. This makes the glucose negatively charged so prevents it passing out of membrane and makes the glucose more energetically favourable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does phosphofructokinase catalyse

A

conversion of Fructose-6-P to Fructose-1,6-biphosphate using energy from ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what does pyruvate kinase catalyse

A

production of Pyruvate from Phosphoenolpyruvate which produces ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

why are there so many steps and enzymes in glycolysis

A

allows parts to be reversed, allows for control, produces useful intermediates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how does glycolysis differ in the liver

A

it is driven by the supply of glucose rather than the need for energy. The liver also uses glucokinase which isn’t inhibited by its products unlike hexokinase

28
Q

true or false: glucokinase has a higher affinity for glucose than hexokinase

29
Q

why are the 2 ATP using reactions in glycolysis irreversible

A

very negative delta G values

30
Q

how is the reducing power captured in glycolysis

A

NAD+ accepts a hydrogen to become NADH

31
Q

how many reversible steps are there in glycolysis

32
Q

true or false: the rate of glycolysis is slower in cancer cells

33
Q

How is Phosphofructokinase regulated

A
  1. Allosterically inhibited by ATP and stimulated by AMP

2. Hormonally inhibited by glucagon and stimulated by insulin

34
Q

what is hexokinase inhibited by

A

its product (Glucose-6-Phosphate)

35
Q

what does high NADH or low NAD+ do to glycolysis

A

inhibits it as these are high energy signals

36
Q

what is the effect of insulin on pyruvate kinase

A

increase in insulin increases the activity of the enzyme and so increase the rate of glycolysis

37
Q

how can fats be produced from glycolysis

A

Fructose-1,6-BP splits to produce Dihydroxyacetone-P. this is then converted into glycerol phosphate in a reduction reaction using NADP. this then combines with fatty acids to produce fat

38
Q

what enzyme catalyses the conversion of dihydroxyacetone to glycerol phosphate

A

glyercol-3-phosphate dehydrogenase

39
Q

what enzyme catalyses the reaction of 1,3-bisphosglycerate into 2,3-bisphophoglycerate

A

Bisphosphoglycerate mutase

40
Q

what does 2,3-Bisphosphoglycerate do

A

lowers haemoglobin affinity for oxygen in RBC

41
Q

how many molecules of NADH are produced in glycolysis

42
Q

what does Lactate dehydrogenate catalyse

A

the conversion of pyruvate to lactate and the reverse

NADH + H+ + pyruvate NAD+ + lactate

43
Q

when are reaction catalysed by lactate dehydrogenase required

A

when you need to regenerate NAD+

low oxygen conditions

44
Q

where is lactate converted back into pyruvate

A

in the heart, kidneys and liver

45
Q

what vitamin deficiency impairs the conversion of lactate to pyruvate in the liver

46
Q

what plasma lactate concentration is classed as lactic acidosis

47
Q

what is the normal lactic plasma concentration

A

below 1 mM

48
Q

what happens in lactic acidosis

A

blood pH is lowered

49
Q

what enzyme catalyses the conversion of Galactose to Galactose-1P

A

Galactokinase

50
Q

what enzyme catalyses the conversion of Galactose-1P into Glucose-1P

A

Uridyl Transferase

51
Q

what enzyme catalyses the conversion of Galactose-1P to UDP-Galactose

A

UDP-galactose epimerase

52
Q

what does deficiencies in any of the enzymes Galactokinase, Uridyl Transferase, UDP-galactose epimerase

A

Galactosaemia

53
Q

what enzyme catalyses the conversion of fructose to Fructose-1P

A

fructokinase

54
Q

what is the result of a deficiency in fructokinase

A

essential fructosuria. This is the incomplete metabolism of fructose, leading to its excretion in the urine with no clinical symptoms

55
Q

what is missing in fructose intolerance

A

the enzyme aldolase

56
Q

what does fructose intolerance result in

A

accumulation of fructose-1-P in the liver leading to liver damage. therefore, remove fructose from the diet

57
Q

what does the enzyme aldolase catalyse

A

splitting of Fructose-1P into Glyceraldehyde and DHAP

58
Q

what does Triose Kinase catalyse

A

conversion of Glyceraldehyde into glyceraldehyde-3-P

59
Q

what does TPI catalyse

A

conversion of DHAP into glyceraldehyde-3-P

60
Q

what does the pentose phosphate pathway start with

A

glucose-6-phopshate

61
Q

what catalyses the conversion of Glucose-6P into 6-Phosphogluconolactone

A

Glucose 6-Phophate dehydrogenase

62
Q

what else is produced during the conversion of Glucose-6P into 6-Phosphogluconolactone

63
Q

what does the pentose phosphate pathway produce

A

Ribose 5-Phosphate (5 carbon sugar)

64
Q

what is Ribose 5-Phosphate required for

A

synthesis of nucleotides, DNA and RNA

65
Q

true of false: ATP is produced in the pentose phosphate pathway

A

false but CO2 is produced

MEH (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions