Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry (material for exam II) > glycolysis and Gluconeogenesis > Flashcards

glycolysis and Gluconeogenesis Flashcards

1
Q

The equation for glycolysis

A

glucose—-> two molecules of pyruvate + 2ATP

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

is glycolysis anaerobic or aerobic

A

anaerobic

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

Where does glycolysis occur

A

The cytoplasm

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

In mammals what is the only fuel that the brain uses under nonstarvation conditions

A

glucose

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

In mammals what is the ONLY fuel that red blood cells can use

A

Glucose

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

Pyruvate and lactate can be salvaged by being resynthesizes to glucose in the metabolic process of

A

gluconeogenesis

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

Sources of glucose in the diet

A

Starch, Glycogen, Disaccharides (especially sucrose and lactose)

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

GLUT 1 has a _____ affinity for glucose and is mostly found where

A

high, RBCs

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

GLUT2 is the main transporter of glucose in the

A

Liver

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

GLUT2 has a _____ affinity with ____ regulation

A

low affinity, No regulation

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

GLUT3 is the main glucose transporter in

A

Neurons

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

GLUT4 is mostly found in

A

skeletal muscle, heart, adipose

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

GLUT4 are dependent on

A

Insulin

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

Glycolysis occurs in the

A

Cytosol

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

What is the purpose of Stage 1 of glycolysis

A

Trapping and preparation phase

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

How many ATP are produced in stage 1 of glycolysis

A

none. 2 ATP are actually consumed

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

What is the final product of stage 1 of glycolysis

A

Fructose 1,6 Biphosphate

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

Stage 1 of glycolysis consists of how many steps

A

3: A phosphorylation, an isomerization, and a second phosphorylation reaction

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

What is the principle strategy of stage 1 of glycolysis

A

to trap the glucose in the cell and form a compound that can be readily cleaved into 2 phosphorylated 3 carbon units

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

What are the two irreversible enzymes used in stage 1 of glycolysis

A

step one- Hexokinase/Glucokinase (in the liver)

step 3: Phosphofructose kinase (PFK) (committed step)

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

what are some differences between hexokinase and glucokinase

A

Glucokinase is in the liver and pancreas B cells while hexokinase is in all other tissues
Hexokinase is readily inhibited by Glucose 6-Phosphate; Glucokinase is not
Glucokinase is has positive feeback from glucose, fructose 1-phosphate, and insulin)
Glucokinase has negative feeback from Glucagon and fructose 6-phosphate

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

What is PFK inhibited by

A

ATP and Citrate

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

What is AMP induced by

A

AMP, Fructose 2,6 Biphosphate

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

Hexokinase like all other kinases requires what for activity

A

Magnesium or another divalent metal ion

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

The isomerization of glucose 6-phosphate to fructose 6-phosphate is a conversion of an ____ into a _____

A

aldose into a ketose

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

What is the allosteric enzyme that sets the pace of glycolysis

A

PFK

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

aldolase converts F-1,6 BP into

A

DHAP and GAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the only glycolytic enzymopathy that is lethal

A

Triose phosphate isomerase deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

When there is high ATP, high NAD+, and low NADH

DHAP is favored over GAP and converted to

A

Glycerol 3-phosphate—–> triacylglycerols—> fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Stage 3 of glycolysis is started by oxidative phosphorylation fo GAP to form _____ (and the reduction of ___ to ____)

A

1,3 BPG ( and the reduction fo NAD+ to NADH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

In stage 3 of glycolysis ADP is phosphorylated to ATP by enzyme ______ and 3-PG is formed via _____

A

Phosphoglycerate kinase, via substrate transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does phosphoglycerate mutase do in glycolysis

A

it moves the phosphate on 3-phosphoglycerate to the 2 carbon thus forming (2-phosphoglycerate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does Enolase do in glycolysis

A

Dehydration of 2-PG forms PEP (phosphoenolpyruvate), an enol with high phosphoryl-transfer potential (unstable)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does pyruvate kinase do in glycolysis

A

transfers phosphoryl group form PEP to ADP to form ATP

PEP is converted from unstable enol to pyruvate, a stable ketone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the three enzymes in glycolysis that are irreversible

A

Hexokinase/glucokinase
PFK (phosphofructokinase)
pyruvate kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

In aerobic environment pyruvate goes to the

A

TCA cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

In an anaerobic environment pyruvate is converted to ____ by _____ and ____

A

lactate, lactate dehyrogenase and NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Pyruvate kinase is induced by

A

insulin

fructose 1,6 BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Pyruvate kinase is inhibited by

A

Alanine
ATP
Glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Pyruvate can be converted into what three things

A

Ethanol, lactate, and Acetyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Alcoholic fermentation and lactate production have no net oxidation-reduction why

A

The NADH formed in the oxidation of glyceraldehyde 3-phosphate is consumed in the reduction of pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Fructose from the liver can enter the glycolysis pathway as

A

DHAP and GAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Fructose can enter as _____ from most most tissue other than the liver

A

Fructose-6P (F-6P)

44
Q

Galactose enters the glycolysis pathway as

A

Glucose-6P (G-6P)

45
Q

In the liver F-2,6-BP has what regulatory effect

A

Activates PFK

46
Q

What effect does citrate have on PFK

A

it inhibits it in the liver

47
Q

Pyruvate kinase is regulated by

A

allosteric effectors and covalent modification

48
Q

High levels of glucagon and low levels of insulin leads to what

A

increase in cAMP pathway and thus increase in protein kinase A this leads to an increase in Fructose 6-Phosphate. Also leads to an inhibition of pyruvate kinase. This means an increase in gluconeogenisis and an inhibition of glycolysis

49
Q

The brain depends on what as its primary fuel source

A

glucose

50
Q

what is RBCs only fuel source

A

Glucose

51
Q

The daily glucose requirement of the brain is about

A

120g

52
Q

What is the whole bodies daily glucose need

A

160g

53
Q

How much glucose is present in body fluids

A

about 20grams

54
Q

how much glucose is readily available from glycogen

A

190grams

55
Q

How long are direct glucose reserves sufficient to meet glucose needs

A

for about a day

56
Q

Neurotransmitters in the brain (Glutamate, Glutamine, GABA) are formed form intermediates of

A

The TCA cycle in the brain (more specifically alpha-ketoglutarate)

57
Q

What are the major precursors of gluconeogenesis

A

Lactate, amino acids, and glycerol (but not fatty acids)

58
Q

What is the purpose of gluconeogenesis

A

converts pyruvate into glucose

59
Q

What are the four enzymes that are present in the gluconeogensis pathway but not in glycolysis

A

pyruvate carboxylase—- converts pyruvate (with ATP, and HCO3) to oxaloacetate ( ADP and Phosphate released)

phosphoenolpyruvate carboxykinase- converted with GTP converts oxaloacetate to phosphoenolpyruvate (GDP and CO2 released)

Fructose 1,6-bisphosphatase- converts fructose 1,6 diphosphate with H2O (Phosphate released)

Glucose 6-phosphatase- with H2O converts glucose 6-phosphate to glucose (phosphate released)

60
Q

what is the mitochondrial enzyme in gluconeogensis

A

Pyruvate carboxylase

61
Q

What happens to oxaloacetate before further gluconeogensis

A

it is transported to the cytoplasm via the malate shuttle

62
Q

Where is glucose 6-phosphatase located

A

in the lumen of the ER

63
Q

Glycolysis _____ ATP, Gluconeogenesis _____ ATP

A

generates, consumes

64
Q

F-2,6 BP and AMP activates

A

glycolysis, more specifically PFK and the converion of fructose 6-phosphate to fructose 1,6 diphosphate

65
Q

fructose 2,6-BP and AMP inhibit

A

Gluconeogenesis, more specifically inhibit fructose 1,6 biphosphatase and the conversion of Fructose 1,6-BP to fructose 6-phosphate

66
Q

ATP inhibits

A

PFK and Pyruvate kinase

67
Q

Alanine inhibits

A

Pyruvate kinase

68
Q

Fructose 1,6 BP activates

A

glycolysis and more specifically pyruvate kinase

69
Q

AMP regulatory effects

A

inhibits gluconeogensis and more specifically fructose 1,6 bisphosphatase

70
Q

What regulatory effect does H+ have

A

inhibits PFK and thus inhibits glycolysis

71
Q

What regulatory effect does ADP have

A

inhibits phosphoenol pyruvate carboxykinase and thus gluconeogensis

72
Q

What regulatory effect does alanine have

A

inhibits pyruvate kinase and thus glycolysis

73
Q

what regulatory effect does acetyl CoA have

A

activates pyruvate carboxylase thus activates gluconeogenesis

74
Q

what is the regulatory effect of ADP

A

inhibits pyruvate carboxylase thus inhibits gluconeogensis

75
Q

tissue location of gluconeogenesis

A

liver (mostly), kidneys, small intestines

76
Q

Favoring conditions for gluconeogensis

A

when blood (glucose) levels are low and glycogen stores are depleted

77
Q

Favoring conditions for glycolysis

A

Favored when blood (insulin) is high

78
Q

Tissue location for glycolysis

A

RBCs, exercising tissues, brain, etc.

79
Q

Subcellular location of glycolysis

A

in the cytosol

80
Q

Subcellualr location of gluconeogensis

A

cytosol and mitochondria

81
Q

Postive regulators of glycolysis

A

Glucose, insulin, AMP, Fructose 2,6-BP, fructose 1,6-BP

82
Q

Postive regulators of gluconeogenesis

A

glucagon, citrate, cortisol, thyroxine, acetyl CoA

83
Q

negative regulators of glycolysis

A

Glucagon, ATP, Citrate, Glucose-6 phosphate, fructose 6-phosphate, alanine

84
Q

negative regulators of gluconeogenesis

A

ADP, AMP, Fructose 2,6-BP

85
Q

energy use and yield of glycolysis

A

uses: 2 ATP
Yield: 4 ATP
Net yield: 2 ATP/glucose oxidized (also produces 2 NADH)

86
Q

energy use and yield of gluconeogensis

A

Uses: 4 ATP, 2 GTP
Yield: 0
Net use: 6 ATP equivalents/ glucose synthesized

87
Q

Sucrose is a disaccharide of

A

glucose and fructose

88
Q

Lactose is a disaccharide of

A

glucose and galactose

89
Q

Fructose and galactose are converted into glycolytic

A

intermediates

90
Q

Fructose is quickly turned to fat in times of

A

high energy

91
Q

Fructose from the liver enters the glycolytic pathway where

A

DHAP/GAP

92
Q

Fructose form adipose tissue enters the glycolytic pathway where

A

Fructose -6P

93
Q

Galactose enters the glycolytic pathway where

A

Glucose-6P

94
Q

Glycogen enters the glycolytic pathway where

A

Glucose-6P

95
Q

In the liver what is the main activator (s) for glucokinase

A

Glucose, Fructose 1-P, insulin

96
Q

In the liver what is the main inhibitor (s) for glucokinase

A

glucagon, fructose 6-P

97
Q

In the liver what is the main inhibitor of PFK

A

Citrate

98
Q

What is the main activator for PFK in the liver

A

Fructose 2,6-BP

99
Q

In the liver pyruvate kinase is largely regulated by

A

allosteric effectors and covalent modification

Meaning ATP and alanine inhibit and Fructose 1,6-BP induce

100
Q

Pyruvate can be oxidized aerobically via the citric acid cycle after first undergoing

A

an oxidative decarboxylation to form acetyl CoA

101
Q

Glucose 6-phosphatase is only found in

A

liver, kidneys, pancreatic Beta cells

102
Q

Cortisol increases the activity of what two enzymes

A

Fructose 1,6 bisphosphatase, glucose 6-Phosphatase thus leading to increase in gluconeogenesis

103
Q

Pyruvate carboxylase is a _____ enzyme

A

mitochondrial

104
Q

What is the purpose of the conversion of pyruvate to oxaloacetate

A

so it can be transported from the mitochondria to the cytoplasm via the malate shuttle

105
Q

Where is glucose 6-phospatase located

A

in the lumen of the ER of liver, kidneys, and pancreatic Beta Cells

Biochemistry (material for exam II) (10 decks)

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