Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Medicinal Chemistry > Carbohydrates > Flashcards

Carbohydrates Flashcards

1
Q

the general formula of carbohydrates

A

Cn(H2O)n

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

monosaccharides

A

single monomer

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

disaccharides

A

2 covalently linked monosaccharides

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

polysaccharides

A

many-covalently linked monosaccharides by O- glycosidic bonds

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

what do monosaccharides contain

A

a carbon chain, an aldehyde/keton, and hydroxyls on each carbon atom except the carbonyl.

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

aldopentose

A

5 carbon saccharide with an aldehyde group

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

keto hexane

A

a 6-carbon saccharide with a ketone group

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

how do we establish a chiral center?

A

we resort to Fischer projections to establish the configuration of the chiral center by comparison with D- or L- glyceraldehyde

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

how do we determine if a carbohydrate is D or L?

A

based on the configuration of the chiral C furthest away from the aldehyde/ketone

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

d-glucose

A
  • known as dextrose
  • building block of the disaccharides sucrose and lactose and of polysaccharides such as cellulose and glycogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

d-galactose

A
  • aldohexose with the formula C6H12O6
  • obtained from lactose found in milk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

galactosemia

A

a condition where the enzyme needed to convert D-galactose to D-glucose is missing. galactose accumulates in the blood and tissue which can lead to cataracts, mental retardation, and liver disease

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

d-fructose

A

ketohexose with the formula C6H12O6
obtained as one of the hydrolysis products of sucrose

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

d-ribose

A
  • an aldopentose with the formula C5H10O5
  • component of RNA
  • has 3 chiral centres
  • reduced form is 2 deoxy-D-ribose which is part of DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

mutarotation

A

takes place in the formation of cyclic forms of monosaccharides. nucleophilic attack from the -OH causes the carbon atom to undergo a change in hybridization from sp2 to sp3.

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

anomers

A

isomers with different chirality at the carbon atom that in the open-chain form is a carbonyl

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

alpha anomer

A

the OH group is pointing down

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

beta anomer

A

the OH group is pointing up

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

mutarotation in fructose

A

makes the glycosylation in glucose and galactose possible

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

what structure do saturated 6-membered rings assume?

A

a half-chair conformation due to sp3 hybridisation

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

which form of monosaccharides can undergo oxidation?

A

open-chain

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

oxidation of monosaccharides with aldehydes

A

if there is an aldehyde group with an adjacent hydroxyl group it can be oxidised to a carboxylic acid by an oxidizing agent such as Benedicts solution

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

oxidation of monosaccharides with ketones

A

ketoses should not undergo oxidation but intermolecular arrangements make monosaccharides oxidizable.

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

reduction of monosaccharides

A

the carbonyl group can be reduced to the corresponding agents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
reducing agents used for the reduction of monosaccharides
Pd + H2 or NaBH4 or enzymatically with the NADH cofactor as a hydride donor
26
describe the condensation of 2 monosaccharides to form a disaccharide
1. one monosaccharide provides the hemiacetal in the form of anomeric carbon 2. one provides a hydroxyl 3. reaction leads to a stable acetal releasing a water molecule
27
the bond between 2 monosaccharides
glycosidic bond which can have a configuration of alpha or beta
28
maltose
has an alpha (1,4) glycosidic bond
29
lactose
glucose + galactose found in breastmilk hydrolyzed by the enzyme lactase
30
sucrose
-consists of a-D-glucose and b-D-glucose - has an alpha-beta (1->2) glycosidic bond between C1 of glucose and C2 of fructose cannot undergo mutarotation and cannot be oxidised
31
taste receptors
proteins that bind to substances that depolarise the cells and transmit a taste signal through facial and cranial nerves.
32
sweet receptors
TAS1R2 and TAS1R3 are found in the palate and the back of the tongue and any molecule that can bind to TAS1 will deliver a sensation of sweetness
33
what cannot the monosaccharide providing the anomeric carbon in the condensation reaction undergo
mutarotation
34
what is the glycosidic bond?
is an acetal
35
hemiacetal + alcohol
nucleophilic substitution. the cyclic hemiacetal can react with other nucleophiles such as NH3 to yield other products
36
N-glycosidic
bond between the nitrogenous base and the ribose
37
homopolysaccharides
single repeating unit
38
how does heterogeneity arise in homopolysaccharides?
from differences in monosaccharides linked together and in the pattern of glycosidic bonds: branching
39
amylose
poly alpha 1,4 glucose linear chains found in plants broken down by enzymes called alpha-amylases
40
amylopectin
poly alpha 1,4 glucose and alpha 1,6 branches branching occurs every 30 glucose units amylopectin associated with amylose via non-covalent hydrogen bonding interactions to form starch
41
cellulose
-poly beta 1,4 glucose - strands of cellulose can establish interchain hydrogen bonds that reduce the solubility and promote the formation of a fibrillar structure - nondigestible: animals lack the enzyme required for the hydrolysis of the beta 1,4 glycosidic bond
42
glycogen
poly alpha 1,4 glucose with a 1,6 branching more branching than amylopectin branching every 8-12 residues
43
why is branching important in glycogen?
1. when glucose is needed, monosaccharides are detached at the non-reducing end of the chain 2. branching offers many ends to the enzymes that catalyze the removal 3. in a time unit, much glucose is released, and glucose increases quickly
44
hemiacetal+ alcohol
acetal + water
45
heteropolysaccharides
when more than one type of monosaccharide is used
46
what can heteropolysaccharides function as
1. structural 2. increasing solubility of proteins 3. shielding proteins from the immune system 4. stabilising extracellular proteins 5. anticoagulants 6. blood groups
47
glycans
polysaccharides associated with other molecules
48
glycosylated proteins
glycans associated with proteins to yield glycosylated proteins
49
n-glycosylation
glycans are attached to Asn residues that are found in consensus sequences -Asn-non Pro- Ser/Thr
50
o-glycosylation
glycans are attached to Ser or Thr residues
51
N-acetyl glucosamine
modified sugar
52
which proteins undergo glycosylation?
extracellular proteins produced in the cell and then secreted or translocated to the cell membrane
53
glycosylation
when a carbohydrate is covalently attached to a macromolecule such as a protein or a lipid
54
Glycosaminoglycans (GAGs)
linear polymers of repeating disaccharides
55
what is the composition and mass of GAGs determined by?
by the relative activities of processing enzymes
56
when do mucopolysaccharides arise
when the activity of breakdown enyzmes is reduced
57
what does a disaccharide of glycosaminoglycan consist of?
uronic acid (sugar with a COOH function) and an amino sugar (sugar with an amino group replacing the OH)
58
how can sugars be modified?
by formation of sulfate esters
59
where are GAGs synthesised?
in the golgi apparatus
60
3 classes of GAGs
heparin/ heparan sulfate chondroitin sulfate/dermatan sulfate keratan sulfate
61
how are GAGs linked to proteins
via O-glycosidic bond or N-glycosidic bond
62
proteoglycans
heavily-glycosylated proteins with one or more GAGs attached to the core polypeptide
63
cartilage composition
composed of collagen, GAGs and proteoglycans
64
heparin GAG
GlcUA/ IdoUA
65
keratan sulfate GAG
Gal neutral or sulfate
66
Chondroitin sulfate GAG
GlcUA
67
Heparan sulfate GAG
GlcUA or IdoUA
68
Dermatan sulfate GAG
GlcUA or IdoUA
69
Hyaluronic acid GAG
GlcUA

Medicinal Chemistry (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions