Brainscape's Knowledge GenomeTM

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


See full index

z S1: Bio Chem 2 > Exam 2 > Flashcards

Exam 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Biology 101 flashcards Organic Chemistry 101 flashcards
1
Q

Glycogen is the readily metabolized storage form of _______

A

glucose

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

Branched homopolymer of glucose linkages are alpha (1-) and alpha (1-) branched

A

4
6

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

Glucose can be added and removed from the ___________ ends of glycogen

A

non-reducing (free 4’-OH)

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

In the liver the synthesis and breakdown of glycogen is regulated to maintain blood ________ levels

A

glucose

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

In the muscle the synthesis and breakdown of glycogen is regulated to meet the _____ requirements

A

energy (when blood glucose levels fall, glycogen will be broken down to release glucose units)

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

What are the three enzymes in glycogenolysis

A

glycogen phosphorylase
phosphoglucomutase
glycogen debranching enzyme

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

A phosphorylase enzyme uses ___ to attack

A

Pi

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

A phosphatase enzyme uses ____ to attack

A

H2O

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

Phosphorylase yields G1P which is _______ meaning it gets trapped in the cell

A

charged

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

What vitamin cofactor does glycogen phosphorylase use

A

Pyridoxal Phosphate (PLP)
Pyridoxine (Vitamin B6)

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

The hydrophobic ring of PLP helps keep ____ out of the active site

A

water (and Pi in)

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

PLP is also the required cofactor for the enzymes in ____ _____ metabolism

A

amino acid

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

Glycogen phosphorylase cleaves off residues without having to dissociate and rebind after each reaction

A

true

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

Glycogen phosphorylase releases ____ and needs ____ to enter glycolysis

A

G1P
G6P

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

Glycogen phosphorylase will stop ___ residues away form a branch point

A

4

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

Debranching enzyme shifts ___ glycosyl units from one strand to another

A

3

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

What organ regulates blood glucose levels

A

liver

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

Glycogen is principally stored in the cytosolic granules of which two organs

A

liver
muscle

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

How is glucose activated in order to be incorporated into glycogen

A

glucose attached to a nucleotide: UDP

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

The activated intermediate _________ serves the substrate for the glycogen synthesizing enzyme

A

UDP-glucose

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

What are the 4 reasons for attaching a nucleotides

A

-attachment is favorable
-sugar nucleotide has many R groups
-a nucleotide is an excellent leaving group
-attaching glucose to UDP creates separate collections of glucose in the cell after a glucose rich meal

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

What three enzymes catalyze the steps involved in glycogen synthesis

A

UDP-glucose pyrophosphorylase
Glycogen Synthase
Glycogen Branching Enzyme

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

Glycogen synthesis can only use the _____ linkages

A

1-4

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

Glycogen synthase can only add onto existing glycogen chains of at least ___ residues long

A

4

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

Insulin stimulates gluose uptake by the _____ receptor

A

Glut4

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

Glycogen branching enzyme transfers a segment of a _____ linked sugar and transfers them on a ____ linkage

A

1-4
1-6

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

The transferred segments in glycogen branching enzyme must be how many residues long

A

11

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

The activity of glycogen synthase and glycogen phosphorylase is controlled by what

A

phosphorylation

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

Glycogen phosphorylase is ______ when phosphorylated

A

active

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

Glycogen synthase is ________ when phosphorylated

A

inactive

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

Glucose binds directly to glycogen phosphorylase and shifts its ________ equilibrium from the active R to the inactive T state

A

allosteric

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

Glucagon and Epi stimulate what and inhibit what

A

stimulate: glycogen breakdown
inhibit: glycogen synthesis

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

Insulin stimulate what and inhibit what

A

stimulate: glycogen synthesis
inhibit: glycogen breakdown

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

Pyruvate can be a source of new glucose made by liver during what

A

gluconeogensis

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

Pyruvate can either be sent out to blood when glucose levels are _____ or stored in liver as ______ for later use

A

low
glycogen

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

Pyruvate can be a source of Acetyl-CoA which can be used to make _____ via CAC and ETC or converted to ____ for energy storage

A

ATP
fat

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

The PDH reaction is a link between glycolysis and ____

A

TCA

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

Oxidative decarboxylation of pyruvate is irreversible because the release of ____ is very favorable

A

CO2

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

For pyruvate dehydrogenase complex what are the three reactions

A

E1: pyruvate dehydrogenase
E2: Dihydrolipoyl Transacetylase
E3: Dihydrolipoyl Dehydrogenase

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

What are the 5 cofactors needed for pyruvate dehydrogenase complex

A

TPP
Lipoate
FAD
NAD+
CoA

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

What is the first step of PDH

A

pyruvate dehydrogenase
require TPP cofactor
Decarboxylation of pyruvate to an aldehyde

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

What is TPP (thiamine pyrophosphate) derived from

A

thiamine
vit B1

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

What is the second step of PDH

A

Dihydrolopoyl Transacetylase
Require Lipoate Cofactor
Oxidation of aldehyde to a carboxylic acid and form acetyl-coA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Lipoate cofactor derived from

A

Lipoic Acid
covalently linked to the enzyme via an amide bond between a NH2 of a lysine residue and the COOH of lipoic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the third step of PDH

A

Dihydrolipoyl Dehydrogenase
Requires FAD and NAD+
Catalyzes reoxidation of lipoamide cofactor and form NADH and regenerate oxidized FAD cofactor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Product inhibitors always bind in the ___________ of the enzymes

A

active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the products of the PDH reaction

A

Acetyl-CoA and NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Feedback inhibitors are allosteric meaning they bind in ________ site on enzyme

A

separate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the feedback inhibitors of PDH

A

ATP and GTP (inhibit)
AMP (activate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What does phosphorylation of E1 vs dephosphorylation of E1 do to PDH

A

phosphorylation: inactivates PDH (kinase)
dephosphorylation: activates PDH (phosphatase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

High ATP -> PDH kinase phosphorylates PDH -> less active PDH -> less ________ made

A

acetyl-coA

52
Q

High AMP -> kinase is less active and PDH phosphatase removes phosphate from PDH -> more active PDH -> more _______ made

A

acetyl-coA

53
Q

PDK kinase is inhibited by what

A

pyruvate
ADP
NAD+
CoA-SH

54
Q

PDH phosphatase is activated by what

A

insulin (high blood glucose)

55
Q

Is PDH enzymes are defective or turned off what builds up

A

lactic acid (its produced from excess pyruvate)

56
Q

What is Rxn 1 of Citric Acid Cycle

A

-carbon to carbon bond formation by condensation of acetyl-CoA and oxaloacetate
-citrate synthase

57
Q

What is Rxn 2 of Citric Acid Cycle

A

-Isomerization by dehydration/rehydration
-Aconitase

58
Q

What is Rxn 3 of Citric Acid Cycle

A

-Oxidative decarboxylation
-Isocitrate dehydrogenase

59
Q

What is Rxn 4 of Citric Acid Cycle

A

-oxidative decarboxylation
-alpha-ketoglutarate dehydrogenase complex

60
Q

What is Rxn 5 of Citric Acid Cycle

A

-Substrate level phosphorylation
-succinyl-CoA synthetase

61
Q

What is Rxn 6 of Citric Acid Cycle

A

-Redox reaction to generate FADH2
-succinate dehydrogenase

62
Q

What is Rxn 7 of Citric Acid Cycle

A

-hydration across double bond
-fumarase

63
Q

What is Rxn 8 of Citric Acid Cycle

A

-oxidation of alcohol to ketone
-malate dehydrogenase

64
Q

the FAD cofactor that accepts the electrons in this reaction is _______ linked to the succinate dehydrogenase enzyme

A

covalently

65
Q

Succinate dehydrogenase is NOT located in the ____________ _______

A

mitochondria matrix (its in the inner layer)

66
Q

The TCA cycle generates how many ATP

A

1

67
Q

What are the regulation steps of the TCA

A

citrate synthase (1)
isocitrate dehydrogenase (3)
alpha-ketoglutarate dehydrogenase (4)

68
Q

What allosterically inhibits citrate synthase

A

ATP
NADH
succinyl CoA

69
Q

What allosterically inhibits isocitrate dehydrogenase, what allosterically activates it, and what product inhibitions it

A

allosterically inhibit: ATP
allosterically activate: ADP
product inhibition: NADH

70
Q

What are the allosteric regulators inhibitors, activators and product inhibitors of TCA

A

allosterically inhibitors: ATP, GTP
allosterically activators: AMP
product inhibitors: succinyl-CoA

71
Q

Citrate is used to make

A

fatty acids/sterols

72
Q

alpha-ketoglutarate is used to make

A

amino acids, purines, pyrimidines

73
Q

succinyl CoA is used to make

A

porphyrin ring of heme

74
Q

oxaloacetate is used to make

A

glucose, amino acids, purines, pyrimidines

75
Q

What are the 4 biosynthetic intermediates of TCA

A

citrate
alpha-ketoglutarate
succinyl CoA
oxaloacetate

76
Q

The act of replenishing TCA cycle intermediates that have been extracted for biosynthesis is called

A

anaplerasis

77
Q

How to make oxaloacetate without using TCA cycle

A

pyruvate

78
Q

Pyruvate carboxylase requires _____ as a cofactor

A

biotin

79
Q

Pyruvate carboxylase is a critical enzyme that is necessary for the synthesis of oxaloacetate from _______ or be used to make new ______

A

pyruvate
glucose

80
Q

How to counteract pyruvate carboxylase deficiency

A

vitamins
glucose-rich diet
not fasting or ketosis

81
Q

What are the 4 major roles of fatty acids

A

building blocks of phospholipids
fuel
hormones
anchor proteins

82
Q

Why are fatty acids such good fuels

A

they are highly regulated and are anhydrous

83
Q

Fatty acids are stored in the body as _____________ esters

A

triacylglyceride

84
Q

What are the two primary sources of TG

A

absorption from the diet not regulated
mobilization of stored fat in adipose tissue highly regulated

85
Q

Dietary TG must be broken down into free _____ ______ before being absorbed

A

fatty acids

86
Q

Most fat absorption occurs in the

A

duodenum

87
Q

TG are incorporated into the micelles with their ester bonds pointing towards _____ of the micelle

A

surface

88
Q

Pancreatic _____ cleave the ester bonds of the triacylglycerols while in the micelles

A

lipases

89
Q

Pancreatic Lipase is the enzyme inhibited by ______

A

Xenical

90
Q

Once inside the cell, the triacylglycerides are reformed and packaged into _______ which enter the lymph system

A

chylomicrons

91
Q

true or false uptake of fatty acids is not regulated

A

true (fatty acids are in the intestines which can not be regulated)

92
Q

What are the three stages of fatty acid processing

A

-triglycerols are degraded to free fatty acids and glycerol in the adipose tissue and transported to other tissues
-fatty acids are activated and transported into the mitochondria
-fatty acids are broken down into two-carbon acetyl-CoA units and fed into the TCA

93
Q

Hormones trigger ______ in adipose tissue

A

lipolysis

94
Q

When triacylglycerol lipase is phosphorylated it is _______

A

active

95
Q

Breakdown of stored fat is controlled by a _______ cascade

A

hormone

96
Q

When blood glucose levels are low or in fight or flight response ____ is broken down for energy needs

A

fat

97
Q

Hydrophobic fatty acids bind to _______ in the blood

A

albumin

98
Q

In order for free fatty acids to be oxidized for energy what needs to occur

A

the COO- group of the free fatty acid must be activated so they can be transported into the mitochondria for degradation

99
Q

Carboxylate converted to thioester = higher energy = ________ group

A

activated

100
Q

What enzyme cataylzes the conversion to make the COO- group of the free fatty acid activated

A

acyl-CoA synthetase

101
Q

The long fatty acid gets attached to a carrier molecule called what

A

carnitine

102
Q

When fatty acids is attached to carnitine the product is what

A

acyl-carnitine

103
Q

What inhibits the attachment of carnitine to a fatty acid tail

A

malonyl-CoA

104
Q

True or False: Fatty acid degradation will occur when fatty acid synthesis is occurring

A

false (the fatty acid will not get transported to the mitochondria where degradation takes place)

105
Q

Defects in carnitine shuttle transport system result in what two things

A

hypoketosis
hypoglycemia

106
Q

The process of FA degradation is called

A

beta oxidation

107
Q

How many carbons are removed at a time in beta oxidation

A

2 carbons

108
Q

What are the 4 processes of beta oxidation

A

oxidation
hydration
oxidation
thiolysis

109
Q

Rxn 1 in beta oxidaiton

A

enzyme: acyl CoA dehydrogenase
electrons passed from FAD to hydride ion then to ETC

110
Q

What are the differences between the 3 forms of acyl-coA dehydrogenases

A

differ in preference in long, medium, or short chain acyl-coA

111
Q

Rxn 2 in beta oxidation

A

enzyme: enoyl CoA hydratase
h2o added across trans C=C

112
Q

Rxn 3 in beta oxidation

A

enzyme: L-hydroxyacyl CoA dehydrogenase
oxidize L-isomer
needs NAD+ which accepts hydride to form NADH
oxidized to form 3-ketoacyl CoA

113
Q

Rxn 4 in beta oxidation

A

enzyme: Beta ketothiolase
cleave thiol group of a new CoA to form acetyl-coA and acyl-coA

114
Q

What is the end result of one beta oxidation rotation

A

1 FADH2
1 NADH
1 Acetyl-CoA

115
Q

The oxidation of fatty acids can be a significant source of what

A

dietary water

116
Q

In odd fatty acids chains what is produced

A

propionyl coA and acetyl coA

117
Q

Propionyl CoA must be converted to TCA intermediate ______________

A

succinyl coA

118
Q

If acetyl-coA can not be released during FA breakdown and enter the TCA cycle what happens

A

-there is not enough oxaloacetate around to turn the cycle
-acetyl coA will be converted to ketone bodies in the liver

119
Q

________ is also a precursor for synthesis of other biomolecules including cholesterol

A

HMG-CoA

120
Q

What are the 3 ketone bodies

A

acetoacetate (used for fuel)
beta-hydroxybutyrate (used for fuel)
acetone (exhaled)

121
Q

Ketone bodies that are made as fuel are made in the liver then ________ in the blood to other tissues for use

A

transported

122
Q

Ketone bodies are a _______ soluble equivalent of acetyl-coA units

A

water

123
Q

How can ketone bodies be used by other tissues

A

acetoacetate is cleaved to produce 2 acetyl-coA units that can be fed into TCA for energy

124
Q

High levels of acetoacetate ____________ fat breakdown

A

decreases

125
Q

When liver beta-hydroxybutyrate is transported to muscle, brain, or other tissues it can be converted to what and can enter what cycle

A

Converted to acetyl-coA
enter TCA cycle

126
Q

During starvation or diabetes, oxaloacetate is used to make glucose which can not be used in the TCA cycle what is the result of this occurrence

A

ketone body production

127
Q

High concentrations of ketone bodies can be harmful and lead to what

A

ketoacidosis (acids decrease blood pH)

z S1: Bio Chem 2 (3 decks)

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