Carbohydrates 2.0 Flashcards Preview

Medicine Term One > Carbohydrates 2.0 > Flashcards

Flashcards in Carbohydrates 2.0 Deck (93)
Loading flashcards...
1
Q

Define glycolysis

A

Cellular reaction splitting glucose to produce ATP without requiring oxygen

2
Q

Products of glycolysis

A

Pyruvate
or
Lactic acid
ATP

3
Q

Whats doe glycolysis do

A

substrate level phosphorylation

4
Q

Gylcolysis is essential for what

A

Red blood cells

and vigorously exercising muscle

5
Q

Whats is the two phases to glycolysis

A

preparation phase

pay of phase

6
Q

For 1 Glc passing through the preparatory phase what is formed

A

2 molecules of G-3-P

7
Q

Whats is needed at preparatory phase of glycolysis

A

2 ATP

8
Q

How much ATP is gained at payoff phase of glycolysis

A

4ATP

9
Q

What is the NET gain of glycolysis

A

2 ATP

10
Q

What causes phosphorylation of glucose

A

hexokinase

11
Q

phosphohexose isomerase catalyses what

A

G6P - fructose 6 phosphate

12
Q

When is glycolysis fixed

A

when fructose 1 6 biphosphate is produced as only needed for glycolysis

13
Q

what causes cleavage in glycolysis

A

highly symmetrical arranged energised molecule that makes it easy to split and from isomers

14
Q

After cleavage what is doubled and can only participate in glycolysis

A

glyceraldehyde 3 phosphate

15
Q

preparation phase ends when

A

after cleavage

16
Q

After cleavage end products are all

A

Doubled

17
Q

oxidation of glyceraldehyde 3 phosphate produces what

A

2 NADH

18
Q

phosphoglycerate kinase and pyruvate kinase catalyses what reaction in glycolysis and produces

A

substrate-level phosphorylation reaction

ATP

19
Q

why does NAD+ need to be regenerated

A

limited supply in cell

20
Q

the pyruvate to lactate reaction allows

A

regeneration of NAD+

21
Q

what is the redox balance

A

NAD+ produced at end of glycolysis transported back to the top, always replenished

22
Q

NO NAD

A

NO GLYCOLYSIS

23
Q

where does limited NAD+ in the cell come from

A

niacin

24
Q

what is the role of NAD+

A

reduction of intermediate metabolites

25
Q

NADH—-> NAD+ is

A

dehydrogenase

26
Q

Pyruvate can be dehydrogenased to

A

ethanol

lactate

27
Q

When is pyruvate converted to lactate

A

cells lacking O2
Vigorously exercising muscle
RBC’s – lack mitochondria

28
Q

Two enzymes catalysing pyruvate to ethanol

A

Pyruvate decarboxylase

Alcohol dehydrogenase

29
Q

when pyruvate is converted to lactate what is oxidised

A

NADH

30
Q

when muscles don’t receive O2 fast enough how is ATP produced

A

substrate-level phosphorylation

31
Q

what are the product of substrate-level phosphorylation,

A

lactate

32
Q

Lactate in converted to glucose by what process

A

gluconeogensis

33
Q

The interaction between the liver and the muscle to produce ATP and lactate is called the

A

Cori cycle

34
Q

Whats repays the oxygen debt to the muscles

A

the liver

35
Q

In the presence of oxygen what is pyruvate oxidised to

A

acetyl coA

36
Q

Where is pyruvate oxidised

A

mitochondria

37
Q

Whats happens to the NADH when pyruvate is oxidised

A

later gives up Hion to respiratory chain

38
Q

how many glycolysis reactions are reversible

A

7

39
Q

Whats do irreversibel reactions have

A

large –ve ΔG

40
Q

What is Gluconeogenesis

A

glucose can be generated from other non-carbohydrate molecules

41
Q

what does Gluconeogenesis respond to

A

Hormone controls

42
Q

Gluconeogenesis is not reverse glycolysis because

A

irreversible reactions in glycolysis is bypassed

43
Q

Irreversible reaction in glycolysis are

A

DePhosphorylation and Phosphorylation reactions
G + ATP —> G6P
F6P + ATP —->
phosphoenoylpyruvate +ADP —> pyruvate and ATP

44
Q

Glucogenesis occurs when

A

ATP conc is high and acetyl coA is low

45
Q

In glucognesis pyruvate carboxylase synthesises what

A

pyruvate acid to oxaloacetate

46
Q

how is oxaloacetate settled out of mitochondria

A

by malate

47
Q

Muscle tissues difference in Gluconeogenesis is

A

lactate dehyrogenased to pyruvate first

48
Q

what happens to G-6-P and F-1,6-bisP in Glucoeogenesis can’t be phosphorylated as is energetically unfavourable

A

hydrolysed

49
Q

Catalyst of bypass reactions in Glucoeogenesis

A

Glucose 6-phosphatase
Fructose 1,6-bisphosphatase
pyruvate carboxylase

50
Q

What is the end product of Glucoeogenesis and why

A

Glucose 6-phosphatase as traps glucose in cells

51
Q

Where does the final step to make free glucose occur

A

the lumen

52
Q

Whats happens after G-6-P is shuttled into the lumen

A

glucose is shuttled back into cytoplasm

53
Q

where is most fructose metabolised

A

liver

54
Q

fructose catabolised by

A

adipose tissue

55
Q

what does the pentose phosphate pathway produce for all organisms

A

NADPH

56
Q

pentose phosphate pathway

A

Converts G-6-P to a pentose phosphate (5C)

57
Q

pentose phosphate is a precursor to

A

ATP, RNA and DNA

58
Q

Whats the two parts to pentose phosphate pathway

A

oxidative irreversible

non-oxidative reversible

59
Q

When is non oxidative phase of pentose phosphate pathway required

A

when lots of NADPH is needed

adipocytes generate alot of FA

60
Q

Non oxidative phase is circular as

A

G-6-P can convert pentose phosphate then back to G6P

61
Q

non reversibel oxidative phase of pentose phosphate pathway required when

A

Molecules need to be broken down

lots of nucleotides are required e.g. rapid cell division

62
Q

When is NADP+ used for

A
anabolism from simple precursors 
inhibits oxygen (antioxidant)
63
Q

When is NAD+ used

A

glycolysis and the citric acid cycle

64
Q

is NADP+ used for metabolism?

A

No

65
Q

Etahnol reduces glycogenesis because

A

uses livers supply of NAD+

66
Q

what is Ethanol broken down to

A

acetly coA

67
Q

inhibits gluconeogenesis leads to

A

lacticacidaemia (increased [blood lactate])

hypoglycaemia (decreased [blood Glc])

68
Q

Black water fever is due to G-6-P dehydrogenase deficiency what does this cause

A

low RBC NADPH levels

damaging free radicals and H2O2 to build up so damages the RBC membranes

69
Q

Overproduction of PEP is called

A

PEPCK

70
Q

what does PEPCK cause

A

produces an overload of energy

71
Q

what is the common metabolic pathway for all “fuel” molecules

A

Citric acid cycle

72
Q

where does citric acid cycle occur

A

mitochondria

73
Q

Does citric acid cycle produce ATP directly

A

No

74
Q

What is the point of citric acid cycle

A

It removes e-’s and passes them on to form NADH and FADH2

75
Q

What is acetyl coA oxidised from

A

pyruvate from glycolysis or fatty acids

76
Q

Series of reactions of 3 subunit pyruvate dehydrogenase enzyme to form acetyl coA

A

decarboxylation of the pyruvate molecule,
oxidation,
transfer of the CoA

77
Q

Pyruvate to acetly coA also produces

A

2 electrons through NADH intermediates

78
Q

How many subunits does pyruvate dehydrogenase

A

three

79
Q

what do the intermediate molecules that make up the citric cycle

A

constant

80
Q

How many turn of the citric cycle per molecule

A

two

81
Q

what is pyruvate dehydrogenase regulated by

A

ATP

82
Q

To much ATP inhibits what

A

pyruvate dehydrogenase

83
Q

what enzymes control the re-direction of cellular resources

A

α-ketoglutarate

isocitrate dehydrogenase

84
Q

what happens when isocitrate dehydrogenase is inhibited as a control point in the citric cycle

A

there is build up citrate that is shuttled back into cytoplasm activating phosphofructokinase to stop glycolysis

85
Q

what is the result of deactivating α-ketoglutarate in citric cycle

A

build up ketoglutarate which is then used for the production of amino acids

86
Q

what pathway is citric acid

A

amphibolic pathway

87
Q

what is amphibolic

A

serves both catabolic and anabolic processes

88
Q

what happens when energy needs are met through citric acid cycle

A

intermediates produce the building blocks of nucleotide bases, heme groups and proteins

89
Q

Build up of acetly CoA triggers what reaction

A

Pyruvate carboxylase converting pyruvate to oxalocaetate

90
Q

What is there an increased concentration of when energy demands are met

A

Acetly coA

91
Q

Over production of ATP cause what pathway

A

pyruvate to oxalocaetate to produce glucose

92
Q

what is anaplerotic reactions

A

form the intermediates of a metabolic pathway

93
Q

pyruvate to oxalocaetate to produce glucose is an example of what reaction

A

anaplerotic reaction

Decks in Medicine Term One Class (59):