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Flashcards in Carbohydrates 2.0 Deck (93):
1

Define glycolysis

Cellular reaction splitting glucose to produce ATP without requiring oxygen

2

Products of glycolysis

Pyruvate
or
Lactic acid
ATP

3

Whats doe glycolysis do

substrate level phosphorylation

4

Gylcolysis is essential for what

Red blood cells
and vigorously exercising muscle

5

Whats is the two phases to glycolysis

preparation phase
pay of phase

6

For 1 Glc passing through the preparatory phase what is formed

2 molecules of G-3-P

7

Whats is needed at preparatory phase of glycolysis

2 ATP

8

How much ATP is gained at payoff phase of glycolysis

4ATP

9

What is the NET gain of glycolysis

2 ATP

10

What causes phosphorylation of glucose

hexokinase

11

phosphohexose isomerase catalyses what

G6P - fructose 6 phosphate

12

When is glycolysis fixed

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

13

what causes cleavage in glycolysis

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

14

After cleavage what is doubled and can only participate in glycolysis

glyceraldehyde 3 phosphate

15

preparation phase ends when

after cleavage

16

After cleavage end products are all

Doubled

17

oxidation of glyceraldehyde 3 phosphate produces what

2 NADH

18

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

substrate-level phosphorylation reaction
ATP

19

why does NAD+ need to be regenerated

limited supply in cell

20

the pyruvate to lactate reaction allows

regeneration of NAD+

21

what is the redox balance

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

22

NO NAD

NO GLYCOLYSIS

23

where does limited NAD+ in the cell come from

niacin

24

what is the role of NAD+

reduction of intermediate metabolites

25

NADH----> NAD+ is

dehydrogenase

26

Pyruvate can be dehydrogenased to

ethanol
lactate

27

When is pyruvate converted to lactate

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

28

Two enzymes catalysing pyruvate to ethanol

Pyruvate decarboxylase
Alcohol dehydrogenase

29

when pyruvate is converted to lactate what is oxidised

NADH

30

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

substrate-level phosphorylation

31

what are the product of substrate-level phosphorylation,

lactate

32

Lactate in converted to glucose by what process

gluconeogensis

33

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

Cori cycle

34

Whats repays the oxygen debt to the muscles

the liver

35

In the presence of oxygen what is pyruvate oxidised to

acetyl coA

36

Where is pyruvate oxidised

mitochondria

37

Whats happens to the NADH when pyruvate is oxidised

later gives up Hion to respiratory chain

38

how many glycolysis reactions are reversible

7

39

Whats do irreversibel reactions have

large –ve ΔG

40

What is Gluconeogenesis

glucose can be generated from other non-carbohydrate molecules

41

what does Gluconeogenesis respond to

Hormone controls

42

Gluconeogenesis is not reverse glycolysis because

irreversible reactions in glycolysis is bypassed

43

Irreversible reaction in glycolysis are

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

44

Glucogenesis occurs when

ATP conc is high and acetyl coA is low

45

In glucognesis pyruvate carboxylase synthesises what

pyruvate acid to oxaloacetate

46

how is oxaloacetate settled out of mitochondria

by malate

47

Muscle tissues difference in Gluconeogenesis is

lactate dehyrogenased to pyruvate first

48

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

hydrolysed

49

Catalyst of bypass reactions in Glucoeogenesis

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

50

What is the end product of Glucoeogenesis and why

Glucose 6-phosphatase as traps glucose in cells

51

Where does the final step to make free glucose occur

the lumen

52

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

glucose is shuttled back into cytoplasm

53

where is most fructose metabolised

liver

54

fructose catabolised by

adipose tissue

55

what does the pentose phosphate pathway produce for all organisms

NADPH

56

pentose phosphate pathway

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

57

pentose phosphate is a precursor to

ATP, RNA and DNA

58

Whats the two parts to pentose phosphate pathway

oxidative irreversible
non-oxidative reversible

59

When is non oxidative phase of pentose phosphate pathway required

when lots of NADPH is needed
adipocytes generate alot of FA

60

Non oxidative phase is circular as

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

61

non reversibel oxidative phase of pentose phosphate pathway required when

Molecules need to be broken down
lots of nucleotides are required e.g. rapid cell division

62

When is NADP+ used for

anabolism from simple precursors
inhibits oxygen (antioxidant)

63

When is NAD+ used

glycolysis and the citric acid cycle

64

is NADP+ used for metabolism?

No

65

Etahnol reduces glycogenesis because

uses livers supply of NAD+

66

what is Ethanol broken down to

acetly coA

67

inhibits gluconeogenesis leads to

lacticacidaemia (increased [blood lactate])
hypoglycaemia (decreased [blood Glc])

68

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

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

69

Overproduction of PEP is called

PEPCK

70

what does PEPCK cause

produces an overload of energy

71

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

Citric acid cycle

72

where does citric acid cycle occur

mitochondria

73

Does citric acid cycle produce ATP directly

No

74

What is the point of citric acid cycle

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

75

What is acetyl coA oxidised from

pyruvate from glycolysis or fatty acids

76

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

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

77

Pyruvate to acetly coA also produces

2 electrons through NADH intermediates

78

How many subunits does pyruvate dehydrogenase

three

79

what do the intermediate molecules that make up the citric cycle

constant

80

How many turn of the citric cycle per molecule

two

81

what is pyruvate dehydrogenase regulated by

ATP

82

To much ATP inhibits what

pyruvate dehydrogenase

83

what enzymes control the re-direction of cellular resources

α-ketoglutarate
isocitrate dehydrogenase

84

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

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

85

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

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

86

what pathway is citric acid

amphibolic pathway

87

what is amphibolic

serves both catabolic and anabolic processes

88

what happens when energy needs are met through citric acid cycle

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

89

Build up of acetly CoA triggers what reaction

Pyruvate carboxylase converting pyruvate to oxalocaetate

90

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

Acetly coA

91

Over production of ATP cause what pathway

pyruvate to oxalocaetate to produce glucose

92

what is anaplerotic reactions

form the intermediates of a metabolic pathway

93

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

anaplerotic reaction

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