280-289 Flashcards

1
Q

https://drive.google.com/open?id=0B8uJUY-tie8GMFhnRnNGMDZ0Ym8

A

https://drive.google.com/open?id=0B8uJUY-tie8GZFpmSVNZV0hRSzA

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2
Q

Glucose metab.

Determines the fate of glucose.

■ —- production per molecule of glucose. The table below assumes that

the — produced in glycolysis is carried into mitochondria via the

—–shuttle. If the glycerol-3-phosphate (G3P) shuttle is used,

the net ATP production would be 36.

A

Determines the fate of glucose.

■ ATP production per molecule of glucose. The table below assumes that

the NADH produced in glycolysis is carried into mitochondria via the

malate–aspartate shuttle. If the glycerol-3-phosphate (G3P) shuttle is used,

the net ATP production would be 36.

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3
Q

https://drive.google.com/open?id=0B8uJUY-tie8GMmNfTVJqZlZBVWM

A

https://drive.google.com/open?id=0B8uJUY-tie8GbUNUWGh4bnJMY2s

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4
Q

glycolysis

A

Also called the Embden–Meyerhof Pathway. (See Figures 7–3.)

■ Occurs in the cytosol, in the absence of O2.

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5
Q

glycolysis

A

Converts glucose (as glucose-6-phosphate) → two molecules of pyruvate.

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6
Q

RLS of glycolysis

A

Conversion of fructose-6-phosphate → fructose-1, 6-biphosphate via phosphofructokinase

(PFK) is the rate-limiting step.

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7
Q

https://drive.google.com/open?id=0B8uJUY-tie8GRnBNRG5VN3d3ZjQ

A

https://drive.google.com/open?id=0B8uJUY-tie8GOWNtOUdrMS1CR28

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8
Q

Glucose +x Pi + y ADP + z NAD+ → 2 Pyruvate +x ATP + y NADH + z H+ + 2 H2O

A

Glucose + 2 Pi + 2 ADP + 2 NAD+ → 2 Pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O

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9
Q

https://drive.google.com/open?id=0B8uJUY-tie8GbC1Fdy1sNVo3MG8

A

https://drive.google.com/open?id=0B8uJUY-tie8GV2d5SVE0a3dLcHM

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10
Q

■ ATP-requiring reactions:■

A

Hexokinase/Glucokinase: glucose → glucose-6-phosphate

■ PFK: fructose-6-phosphate → fructose-1,6-bisphosphate

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11
Q

ATP-producing reactions:■

A

Phosphoglycerate kinase: 1,3-bisphosphoglycerate → 3-phosphoglycerate

Pyruvate kinase: phosphoenolpyruvate → pyruvate

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12
Q

PYRUVATE DEHYDROGENASE

■ Pyruvate + NAD+ →

A

Acetyl-CoA + CO2 + NADH

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13
Q

5 cofactors

A

Pyrophosphate (B1, thiamine)

■ FAD (B2, riboflavin)

■ NAD (B3, niacin)

■ CoA (B5, pantothenate)

■ Lipoic acid

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14
Q

Also called the Cori cycle (See Figure 7–4.)

■ Occurs in the liver

A

lactic acid cycle

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15
Q

LA cycle

A

Prevents lactic acidosis

■ Converts lactate → glucose, which is then reoxidized via glycolysis

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16
Q

LA cycle

A

Provides quick ATP production during anaerobic glycolysis in muscle and

erythrocytes

■ Results in net loss of 4 ATP per cycle

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17
Q

Citric Acid cycle

A
  • Krebs cycle and the tricarboxylic acid cycle.
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18
Q

Citric acid cycle

A

Occurs in the mitochondrial matrix.

■ Completes the metabolism of glucose.

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19
Q

Citric acid cycle

A

Oxidizes acetyl-CoA.

Reduces NAD+ and FAD → NADH and FADH2, which are reoxidized in

the ETC to produce ATP.

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20
Q

citric acid cycle

A

Tightly regulated by both ATP and NAD+.

■ Stoichiometry of TCA cycle:

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21
Q

Acetyl-CoA + 3 NAD+ + FAD + Pi + GDP + 2 H2O →

A

2 CO2 + 3 NADH + FADH2 + GTP + 2 H+ + CoA

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22
Q

https://drive.google.com/open?id=0B8uJUY-tie8GU1BjREx1R0tDc1k

A

https://drive.google.com/open?id=0B8uJUY-tie8GUHVxSVNzczBVU0E

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23
Q

ETC

A

Also called the respiratory chain (See Figure 7–5.)

■ Occurs in the inner mitochondrial membrane.

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24
Q

ETC

A

Produces ATP via oxidative phosphorylation of ADP.

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25
Q

ETC

A

Reoxidizes NADH and FADH2 back → NAD+ and FAD as electrons flow

through a series of —– cytochrome complexes of increasing —- potential

(along a —– gradient).

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26
Q

Cytochromes contain a

A

Cytochromes contain a central iron atom (similar to hemoglobin), which

can exist in an oxidized ferric (Fe3+) state or a reduced ferrous (Fe2+) state.

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27
Q

Cytochromes receive electrons from

A

the reduced form of coenzyme Q

(ubiquinone).■

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28
Q

Cytochromes carry electrons as?

A

Cytochromes carry electrons as flavins, iron-sulfur groups, hemes, and

copper ions

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29
Q

https://drive.google.com/open?id=0B8uJUY-tie8GMVVfa19xeUgzM3M

A

https://drive.google.com/open?id=0B8uJUY-tie8GWXlLVnpOOHBPcU0

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30
Q

https://drive.google.com/open?id=0B8uJUY-tie8GQTR0VEowWmNLMTg

A

https://drive.google.com/open?id=0B8uJUY-tie8GNWdVZjBKTlRGNTQ

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31
Q

THE PENTOSE PHOSPHATE PATHWAY

A

Also called the hexose monophosphate shunt.

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32
Q

Glucose-6-phosphate + 2 NADP+ + H2O →

A

Glucose-6-phosphate + 2 NADP+ + H2O → Ribose-5-phosphate + 2 NADPH + 2 H+ + CO2

THE PENTOSE PHOSPHATE PATHWAY

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33
Q

THE PENTOSE PHOSPHATE PATHWAY

A

Occurs in the cytosol.

■ An alternative to glycolysis in the metabolism of glucose.

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34
Q

THE PENTOSE PHOSPHATE PATHWAY

A

Coverts glucose-6-phosphate → ribose-5-phosphate

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35
Q

RLS of Pentose phos pathway

A

Conversion of glucose-6-phosphate → 6-phosphogluconolactone via

glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting step.

36
Q

THE PENTOSE PHOSPHATE PATHWAY

A

Produces ribose (for nucleotide synthesis) and NADPH (for fatty acid and

steroid synthesis).

37
Q

pentose phos pathway

A

Not all cells use the PPP (most active in liver, adipose tissue, adrenal cortex,

thyroid, mammary gland, testis, and erythrocytes).

38
Q

Pyruvate + 2 ATP + GTP + NADH + 2 H2O→

GLUCONEOGENESIS

A

Pyruvate + 2 ATP + GTP + NADH + 2 H2O→ Glucose-6-phosphate + 2 ADP + GDP + 3 Pi + NAD+ + H+

GLUCONEOGENESIS

39
Q

gluceoneogenesis

A

Occurs mostly in the liver and kidneys

■ Not a direct reversal of the glycolysis

40
Q

gluconeogenesis

A

Converts amino acids → glucose or glycogen in states of carbohydrate need

41
Q

gluconeugenesis

A

Clears lactic acid (from anaerobic glycolysis) and glycerol (from fatty acid

metabolism)

■ Under strict hormonal regulation

42
Q

https://drive.google.com/open?id=0B8uJUY-tie8GdTVHTVZ1TENjMFE

A

https://drive.google.com/open?id=0B8uJUY-tie8GdklTME1aV0EyaXc

43
Q

Glycogen synthase:

A

Glycogen synthase: Key regulatory enzyme in its synthesis. Uses UDPglucose

and the nonreducing end of glycogen as its substrate.

44
Q

Glycogenin:

A

Primer for glycogen synthase by catalyzing the addition of

glucose to itself

45
Q

Glycogen phosphorylase:

A

Key regulatory enzyme in its catabolism.

■ Under strict hormonal regulation.

46
Q

Occurs in the cytosol of mostly hepatocytes.

A

FATTY ACID SYNTHESIS

47
Q

rls of FA synthesis

A

The irreversible conversion of acetyl-CoA → malonyl-CoA via acetyl-CoA

carboxylase is the rate-limiting step.

48
Q

FA synthesis

A

Conversion of acetyl-CoA → malonyl-CoA is the rate-limiting step.

49
Q

■ Citrate–malate shuttle transports acetyl groups from mitochondria to the

cytoso

A

FA synthesis

50
Q

https://drive.google.com/open?id=0B8uJUY-tie8GaW42ZFRtbFpyWVk

A

https://drive.google.com/open?id=0B8uJUY-tie8Gd0lpaGpHMVA3SVE

51
Q

TRIGLYCERIDE LIPOLYSIS

A

Occurs in adipocytes.

■ The glycerol is phosphorylated and ultimately oxidized in glycolysis

52
Q

TRIGLYCERIDE LIPOLYSIS

A

The free fatty acids are transported to the liver for b-oxidation.

■ Triacyglycerol lipase is under strict hormone regulation.

53
Q

https://drive.google.com/open?id=0B8uJUY-tie8GN25ETHF5S2ZGejQ

A

https://drive.google.com/open?id=0B8uJUY-tie8GUWZvMGJQUkFhOU0

54
Q

beta oxidation

A

Occurs in the mitochondrial matrix of hepatocytes.

■ Converts acyl-CoA → acetyl-CoA.

55
Q

Fatty acids are carried into the mitochondrial matrix by a x -mediated

enzyme system

A

Fatty acids are carried into the mitochondrial matrix by a carnitine-mediated

enzyme system

56
Q

https://drive.google.com/open?id=0B8uJUY-tie8GRWdYNDduREVDWGc

A

https://drive.google.com/open?id=0B8uJUY-tie8GUDZfUUZlRzgtWms

57
Q

Under certain metabolic states (starvation, diabetes mellitus), much of the

acetyl-CoA is converted to—–

A

Under certain metabolic states (starvation, diabetes mellitus), much of the

acetyl-CoA is converted to ketone bodies:

58
Q

Acetoacetate: synthesized by cleavage of

A

Acetoacetate: synthesized by cleavage of HMG-CoA

■ b-Hydroxybutyrate

■ Acetone

59
Q

Ketone bodies are a source of fuel in—– tissues such as x

and y muscle

A

Ketone bodies are a source of fuel in extrahepatic tissues such as skeletal

and cardiac muscle

60
Q

Ketosis is the accumulation of ketone bodies leading to

A

Ketosis is the accumulation of ketone bodies leading to ketoacidosis and

diabetic coma

61
Q

https://drive.google.com/open?id=0B8uJUY-tie8GRzVZX19ISjFjRzA

A

https://drive.google.com/open?id=0B8uJUY-tie8GZnBpWHN1bHFsQlE

62
Q

Both dietary and structural proteins are degraded daily to their amino acid

constituents by various x and y

A

Both dietary and structural proteins are degraded daily to their amino acid

constituents by various proteases and peptidases.

63
Q

https://drive.google.com/open?id=0B8uJUY-tie8GU1BiajhXY3F2Y3c

A

https://drive.google.com/open?id=0B8uJUY-tie8GeXQ2bVdCUEVMdnc

64
Q

Amino acids are used to synthesize other

A

Amino acids are used to synthesize other amino acids (and proteins) or

metabolic intermediates (pyruvate, acetyl-CoA, oxaloacetate, succinyl CoA,

and a-ketoacids).

65
Q

Aminotransferases (transaminases) cleave the —–

nitrogen of most

amino acids, leaving —- skeletons, which are degraded to the various

—– and —— intermediates.

A

Aminotransferases (transaminases) cleave the a-amino nitrogen of most

amino acids, leaving hydrocarbon skeletons, which are degraded to the various

glucogenic and ketogenic intermediates.

66
Q

Requires either —- phosphate or —— phosphate, forms of pyridoxine

(vitamin B6), as a coenzyme

A

Requires either pyridoxal phosphate or pyridoxamine phosphate, forms of pyridoxine

(vitamin B6), as a coenzyme

TRANSAMINATION

67
Q

The transamination of pyruvate to alanine yields either

A

a-ketoglutarate or

oxaloacetate

68
Q

https://drive.google.com/open?id=0B8uJUY-tie8GVDlyaXFWUGwzR3M

A

https://drive.google.com/open?id=0B8uJUY-tie8GS1pCWkFCY2lpUzA

69
Q

https://drive.google.com/open?id=0B8uJUY-tie8GbWVJQ0EzU1IzZk0

A

https://drive.google.com/open?id=0B8uJUY-tie8Gem16OGlzUGtMbTQ

70
Q

https://drive.google.com/open?id=0B8uJUY-tie8GUU9jOFFsYjE4aDA

A

https://drive.google.com/open?id=0B8uJUY-tie8GR3lfYjBDZ1k0c2s

71
Q

ox deam.

A

An alternative to transamination in the metabolism of amino acids.

■ Results in the formation of α-ketoacids (for energy) and ammonia (for

urea formation).

72
Q

ox. deam.

A

Oxidative deamination of glutamate

73
Q

L-Glutamate + NAD(P)+ + H2O–>

A

α-Ketoglutarate + NAD(P)H + NH4

+ + H+

74
Q

ox deam.

A

The reaction is reversible but favors the formation of glutamate.

75
Q

ox deam.

A

Occurs mostly in the liver and kidneys.

■ In humans, the vast majority of oxidative deamination derives from glutamate;

the major enzyme responsible is glutamate dehydrogenase.

76
Q

Other amino acids that can undergo oxidative deamination are

A

asparagine,

histidine, serine, and threonine (Table 7–3).

77
Q

https://drive.google.com/open?id=0B8uJUY-tie8GcUR2TlVoeWtINEE

A

https://drive.google.com/open?id=0B8uJUY-tie8GbGEwSXoweGFWX0E

78
Q

https://drive.google.com/open?id=0B8uJUY-tie8GbVpUUl8teUgzZnc

A

https://drive.google.com/open?id=0B8uJUY-tie8GNFd1TTVXWk5NZ28

79
Q

urea cycle

A

Occurs in the cytosol and mitochondrial matrix of hepatocytes.

■ Eliminates the ammonia (NH4

+) produced by oxidative deamination in

the form of urea (Figure 7–11).

80
Q

CO2 + NH4

+ + 3 ATP + Aspartate + 2 H2O →

A

Urea + 2 ADP + 2 Pi + AMP + PPi + Fumarate

81
Q

The excess nitrogen is converted to urea ■

A

and excreted by the kidneys.

UREA CYCle

82
Q

Complete block of the cycle leads to extensive xy

A

Complete block of the cycle leads to extensive ammonia accumulation

83
Q

liver cirrhosis (eg, from alcoholism) results in x carbamoyl

phosphate synthase.

A

liver cirrhosis (eg, from alcoholism) results in ↓ carbamoyl

phosphate synthase.

It is fatal since there is no alternative pathway.

84
Q

An alternative method of glycolysis to the Embden-Meyerhof or pentose

phosphate pathways.

A

ENTNER –DOUDOROFF PATHWAY

85
Q

ENTNER –DOUDOROFF PATHWAY

A

Used most commonly by aerobic bacteria.

■ Converts glucose → pyruvate + glyceraldehyde-3-phosphate

86
Q

ENTNER –DOUDOROFF PATHWAY

A

Produces 1 ATP per glucose via substrate-level phosphorylation

87
Q
A