Brainscape's Knowledge GenomeTM

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


See full index

BIOCH 320 > carbohydrates 3 - heteropolysaccharides > Flashcards

carbohydrates 3 - heteropolysaccharides Flashcards

1
Q

what is a heteropolysaccharide

A

a mixture of monosaccharide units

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

what are 3 examples of structural opolysaccharides

A

peptidoglycans
agarose
glycosaminoglycans

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

what are peptidoglycans (basic)

A

bacterial cell walls

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

what are glycosaminoglycans (basic)

A

extracellular matrix in animals

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

what 2 types of things compose petidoglycans (general)

A

mixture of polysaccharides and peptide-like structures

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

what 2 things compose petidoglycans (specific)

A

alternating NAH (GlcNAc, N-acetylglucosamine) and NAM (Mur2Ac) N-acetlmuramic acid

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

what joins NAG and NAM

A

beta 1–>4 glycosidic bonds

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

is peptidoglycan linear or not

A

linear

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

is peptidoglycan crosslinked and where and how(by what)

A

yes, adjacent chains are crosslinked by peptide-based structures

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

whats in the peptide crosslinks of peptidoglycan

A

L and D amino acids

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

where are the peptide cross links joined in peptidoglycan

A

via the Lys side chain to adjacent pentaglycine groups

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

is the structure of the peptide-like cross-linking the same in Gram + and -

A

no

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

what does lysozyme do

A

breaks bonds between adjacent monosaccharide units

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

what enzyme breaks bonds between adjacent monosaccharide units in peptidoglycan

A

lysozyme

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

what does penicillin do

A

inhibits formation of peptide cross-links

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

what kind of bonds join the NAG NAM carbohydrate to the tetra peptide in peptidoglycan

A

amide bond

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

how does the 5 glycine connect to do tetra peptide in peptidoglycan

A

amide bond from side chain of lysine to the pentaglycine

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

what is the role of glycosaminoglycans in the extracellular matrix

A

porous network that supports cells

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

what does glycosaminoglycan associate with

A

fibrous proteins like collagen

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

are glycosaminoglycans part of a conjugated protein structure

A

yes they can be

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

what are unbranched heteropolysaccharides

A

repeating disaccharides in linear chains

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

what composes unbranched heteropolysaccharides (what specifically)

A

mixture of uronic acid derivatives and glucosamine/galatosamine derivatives

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

what happens to lots of glycosaminoglycans (structurally)

A

become sulfated or carboxylated derivatives

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

what charge do glycosaminoglycans have and why

A

more negative because the sulfate and carboxylated derivatives are negative

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

how does the structure adapt due to the negatively charged molecules present in glycosaminoglycans and how

A

it adopts a linear extended structure to reduce charge repulsion

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

what kind of interactions are glycosaminoglycans involved in

A

intermolecular

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

what is so special about heparin

A

it is very negatively charged

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

what kind of groups cause negative charges on glycosaminoglycans

A

sulfate or carboxylate

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

what class of molecule is hyaluronic acid / hyaluronate

A

glycosaminoglycans

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

what class of molecule is chondroitin sulfate

A

glycosaminoglycans

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

what class of molecule is heparin

A

glycosaminoglycans

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

how does heparin prevent blood clotting

A

binding to a protein via electrostatic interactions

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

what is the shape of heparin and why

A

very extended to minimize electrostatic interactions (high charge density)

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

what makes heparin so negative

A

sulfate group, carboxyl group

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

why does heparin adopt a highly extended structure

A

to minimize charge repulsion between negatively charged groups

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

what kinds of things can be used to create informational structures (cell recognition, cell surface binding, receptor interactions)

A

polysaccharides and oligosaccharides as glycoconjugates

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

what are the roles of glycoconjugates

A

can be used to create informational structures (cell recognition, cell surface binding, receptor interactions)

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

what is an example of a peptide structure glycoconjugate

A

peptidoglycan

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

what is peptidoglycan (what kind of glycoconjugate)

A

peptide structure glycoconjugate

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

what are 2 examples of a protein glycoconjugates

A

Proteoglycans and glycoproteins

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

what is an example of a lipid glycoconjugate

A

glycolipid

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

whats a glycolipid

A

lipid glycoconjugate

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

whats a Proteoglycans

A

protein glycoconjugates

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

whats a glycoproteins

A

protein glycoconjugates

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

whats the general difference with proteoglycans and glycoproteins (like classification)

A

all proteoglycans are glycoproteins but not all glycoproteins are proteoglycans

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

what are in for proteoglycans (what are the components in it)

A

glycosaminoglycan/ protein glycoconjugate

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

what is another name for glycosaminoglycan/ protein glycoconjugate

A

proteoglycan

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

what is the major component of glycosaminoglycan

A

the heteropolysaccharide (glycosaminoglycan + uronic acid derivatives)

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

how are the “core proteins” from the proteoglycan linked to the glycosaminoglycan

A

covalently via glycosidic bonds to Ser side chains

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

what are 2 common locations of proteoglycans

A

extracellular matric or integral membrane structures

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

where are the carbs usually located in the cell with proteoglycans

A

extracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what is syndecan (1 word, its class)

A

proteoglycan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what is the role of syndecan

A

cell binding, receptor and cytoskeletal interactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

how is the core protein of syndecan anchored in the cell membrane

A

via a single alpha helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

what is attached to syndecan and where

A

multiple glycosaminoglycans attached on the extracellular (N terminal) side

56
Q

which is the N terminal side of the syndecan core protein

A

on the extracellular site

57
Q

which glycosaminoglycans are attached to syndecan

A

chondroitin sulfate and heparin sulfate

58
Q

how is chondroitin sulfate and heparin sulfate connected to syndecan

A

via glycosidic linkages to serine side chains

59
Q

is the reducing or non reducing end of the sugar attached to syndecan and why

A

reducing end (need anomeric carbon to attach to serine)

60
Q

where is the site of intermolecular/binding interactions in syndecan

A

the glycosaminoglycans

61
Q

what is the overall structure of syndecans and why

A

they are extended owing to negative charges

62
Q

what is the general structure of the condroitin sulfate that links to the serine (and how does it link)

A

the glycosaminoglycan core (repearing uronic acid structure) then a trisaccharide linker ending in Xyl binds to the serine

63
Q

which monosaccharide links to serine in the proteoglycan structure

A

Xylose

64
Q

which amino acid does xylose link to in the proteoglycan structure

A

serine

65
Q

which monosaccharide often joins glycosamined glycans

A

xyl

66
Q

which part of xylose is attached to serine of the core protein

A

the anomeric carbon

67
Q

what is the concensus sequence of the attachment site

A

serine glycine X glycine

x=anything

68
Q

is sulfanation of heparin constant

A

no it has variable degrees

69
Q

what are the NA domains of heparan sulfate

A

the portions that remain as unmodified disaccharide repeats

70
Q

what are the portions that remain as unmodified disaccharide repeats

A

NA domain

71
Q

what are the NS domains of heparan sulfate

A

the portions that become heavily derivatized, particularly sulfated

72
Q

what are the portions that become heavily derivatized, particularly sulfated

A

NS domains

73
Q

when do the heparan sulfate domains become modified and how

A

enzymes modify them after synthesis

74
Q

what happens to the charge ones the domains of heparan become derivatized

A

they become more negative

75
Q

what structure changes when they change the carbohydrate (2 things, kinda weird)

A

allostery, 3ary structure changes

76
Q

what is the role of NS domains (what do they do)

A

bind to different proteins and affect their activity

77
Q

what mediates NS domain binding

A

electrostatic/ polar interactions

78
Q

what are 3 different ways that NS domain interactions occur

A
  • allostery/enhanced binding effects on proteins
  • acting as co-receptors for extracellular ligands
  • cell surface localization
79
Q

do you expect + or - groups to interact with NS domains

A

+ve

80
Q

what does HS binding do when there are more than 1 protein bound

A

it increases the interactions between the proteins

81
Q

what can increased NS sites do to concentration of ligands near the membrane and why

A

it can increase it because there are more receptor ligand interactions with the NS sites

82
Q

what can happen to concentration of ligands near the membrane when sulfanation is removed and why

A

less NS sites so less ligand interactions so lower concentration

83
Q

how do proteoglycans affect ligand-receptor interactions

A

they enhance

84
Q

what is something that HS-ligand-receptor complexes can be associated with

HS=heparin sulfate

A

endocytosis of receptor complexes

85
Q

what happens when the HS containing structures are shedded (endocytosis of receptor complexes)

HS=heparin sulfate

A

bound ligands and HS will be dissociated from cell surface

so the HS-ligand-receptor complex will undergo endocytosis and the other HS chain and ligand portions will shed off the membrane

86
Q

what happens when lipoprotein lipase binds to heparan-sulfate proteoglycans

A

increase its concentration/localization near the membrane when the proteoglycan is membrane-bound

87
Q

what does binding of lipoprotein lipase to heparan-sulfate proteoglycans do to reaction rate and why

A

increases rate of reaction with increase Vmax (increased concentration of enzyme near membrane)

88
Q

what are 2 ways that membrane bound proteoglycans can be anchored

A

by transmembrane protein domains or by lipid domains

89
Q

what are glypicans

A

phospholipid anchords to membrane

90
Q

how can you cleave proteoglycans from membrane

A

phospholipase

91
Q

how can you cleave glypicans from membrane

A

protease

92
Q

what are glycoproteins

A

protein/carbohydrate conjugats

93
Q

are all proteoglycans glycoproteins

A

yes

94
Q

are all glycoproteins proteoglycans

A

no

95
Q

what portion of the glycoprotein differs from proteoglycans

A

carbohydrate portion

96
Q

how does the carbohydrate portion of glycoprotein differs from proteoglycans

A

smaller (oligosaccharides)
more branched
greater variety of saccharides

97
Q

are there more disaccharide repeats in glycoproteins or proteoglycans

A

more in proteogylcans

98
Q

is glycoproteins or proteoglycans more extended and linear

A

proteogylcans

99
Q

is glycoproteins or proteoglycans more complex

A

glycoproteins

100
Q

is glycoproteins or proteoglycans more branching

A

glycoproteins

101
Q

is glycoproteins or proteoglycans more variablity

A

glycoproteins

102
Q

how does the carb attach to the protein in glycoproteins and how (What kind of attachment)

A

covalently attached via serine threonine or asparagine

103
Q

what are O-linked glycoproteins

A

ones where the carb is attached via a serine or threonine

104
Q

what are N-linked glycoproteins

A

ones where the carb is attached via a asparagine

105
Q

what kind of linkages are in O-linked oligosaccharides

A

glycosidic

106
Q

what kind of linkages are in N-linked oligosaccharides

A

N-glycosyl

107
Q

what are the glycosidic bonds like in O-linked glycoproteins

A

oligosaccharide linked to the oxygen of a ser or thr

108
Q

what are the N-glycosyl bonds like in N-linked glycoproteins

A

oligosaccharide linked to the nitrogen of an asn

109
Q

what are the N-glycosyl bonds like in N-linked glycoproteins

A

oligosaccharide linked to the nitrogen of an asn

110
Q

can you have more than one of the O or N linkages in a single protein

A

yes (oligosaccharides may constitute up to 70% of the mass)

111
Q

are N or O linkages more common and straightforwards

A

N

112
Q

is there more mannose in mature or unmatured oligosaccharides

A

in non-mature ones

113
Q

what does glycosylation of proteins lead to (general)

A

a change in the chemical nature of proteins

114
Q

what are 4 changes in chemical nature of proteins that happens when they become glycosylated

A

polarity
solubility
folding (tertiary structure)
interactions with other proteins

115
Q

what are 3 interactions with other proteins that may change when proteins become glycosylated

A
  • recognition (sorting, signalling)
  • protection from proteolysis
  • antigenicity (antibody binding)
116
Q

which structure does adding oligosaccharides do

A

changes tertiary

117
Q

when does N-linked glycolsylation occur

A

during protein synthesis in rough ER

118
Q

which side of the ER does carbohydrate attachment occur

A

on the lumen side

119
Q

where is initial glycosylation processed durther

A

ER and golgi

120
Q

where does the glycosylated product sent to determine final location and glycosylation structure

A

golgi

121
Q

what are 3 reasons that oligosaccharides are a rich source of structural variation

A
  • multiple monosaccharides as derivatives
  • branched structures
  • glycosidic configuration variations
122
Q

what kind of interactions can oligosaccharides in glycoproteins and glycolipids be used for

A

recognition structure for intermolecular interactions

123
Q

what are 4 intermolecular interactions that oligosaccharides in glycoproteins and glycolipids be used for

A
  • protein targeting/sorting
  • cell-cell interactions
  • signalling
  • tissue development
124
Q

order the hexa-polymers in order of least to most…

  • hexapeptide
  • oligosaccharide
  • hexanucleotide
A

hexanucleotide (4^6)
hexapeptide(20^6)
oligosaccharide(billions)

125
Q

what are lectins

A

proteins that bind to carbohydrates (oligosaccharides) with high specificity

126
Q

which organisms contain lectins

A

all of them

127
Q

what are 4 roles of lectins

A
  • cell-cell recognition
  • signalling
  • adhesion
  • intracellular targeting of newly synthesized proteins
128
Q

what kind of interactions do lectins do

A

protein ligand interactions

129
Q

where do oligosaccharides (or parts of them) interact with lectins

A

with binding sites

130
Q

what kind of binding process occurs with lectins

A

equilibrium binding process (Kd values become relevent)

131
Q

what are cell surface oligosaccharides expressed as

A

glycolipids and glycoproteins

132
Q

how do infectious agents use lectins

A

to interact specifically with surface oligosaccharides (glycolipids and glycoproteins)

133
Q

what is the specificity of oligosaccharide expression

A

tissue and cell type specific

134
Q

what do selectins do

A

mediate normal cell-cell interactions

135
Q

which lectin mediates normal cell-cell interactions

A

selectins

136
Q

what mediates intracellular traffic and sorting

A

lectin/oligosaccharide interactions

137
Q

what binds to Galectin-2

A

lactose (Gal(beta1–>4)Glc)

BIOCH 320 (16 decks)

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