Carbohydrates and Monosaccharides Flashcards
1
Q
The most abundant class of bioorganic molecules on earth
A
Carbohydrates
2
Q
produced by the photosynthetic activity of the green plants
A
Carbohydrates
3
Q
Co2 + H2O + Solar energy Chlorophyll Plant enzymes >
A
Carbohydrates + O2
4
Q
also referred to as saccharides because of the sweet taste of
many carbohydrates
A
Carbohydrates
5
Q
A
6
Q
(Latin, saccharum, meaning
A
sugar
7
Q
(Latin, saccharum, meaning sugar)
A
Carbohydrates
8
Q
storehouse of chemical energy
A
Carbohydrates
9
Q
3 examples of storehouse of chemical energy
A
glucose, starch, glycogen
10
Q
– a gram of digested carbohydrate gives about how many kcal of energy?
A
4 kcal
11
Q
complex carbohydrates are best for
A
diet
12
Q
supportive structural components in plants and some animals
A
Carbohydrates
13
Q
2 examples of supportive structural components in plants and some
animals
A
(cellulose, chitin)
14
Q
form part of the structural framework of DNA &
RNA
A
Carbohydrates
15
Q
carbohydrate “markers” on cell surfaces play key roles in
A
cell-cell recognition
16
Q
2 compounds that
produce such substances upon hydrolysis.
A
polyhydroxy aldehydes or polyhydroxy ketones
17
Q
simple sugars
A
Monosaccharides
18
Q
contain a single polyhydroxy aldehyde or polyhydroxy ketone unit
A
Monosaccharides
19
Q
cannot be degraded into simpler products by hydrolysis reactions
A
Monosaccharides
20
Q
pure monosaccharides are water- soluble, white, crystalline solids
A
Monosaccharides
21
Q
contains 2 monosaccharide units covalently bonded to each other
A
Disaccharides
22
Q
- crystalline and water soluble substances
- upon hydrolysis they produce monosaccharides
A
Disaccharides
23
Q
A
24
Q
contains 2-10 monosaccharide units - covalently bonded
A
Oligosaccharide
25
disaccharides are its most common type
Oligosaccharide
26
trisaccharides
(raffinose)
27
tetrasaccharides
(stachyose)
28
are less common in nature
oligosaccharides
29
usually found associated with proteins and lipids in
complex molecules that serve structural and regulatory
functions
Oligosaccharide
30
consist of tens of thousands of
monosaccharide units covalently
bonded
Polysaccharides
31
2 kinds of Polysaccharides
homopolysacchrides
heteropolysaccharides
32
polymers of a single
monosaccharide
homopolysacchrides
33
3 examples of homopolysacchrides
(glycogen, cellulose, starch)
34
contain more than one kind of
monosaccharide
heteropolysaccharides
35
3 examples of heteropolysaccharides
(hyaluronic acid, heparin, chondroitin sulfate)
36
a homopolysaccharides used for measuring glomerular filtration rate
insulin
37
consists of N-acetyglucosamine + glucoronic acid not covalently attached to protein
hyaluronic acid
38
acts as lubricant and shock absorber present in synovial fluid, vitreous humor, umbilicla cord, loose connective tissue
hyaluronic acid
39
composed of N-acetylglucosamine + glucoronic acid which is present in cartilage, tendons, and ligaments
chondroitin sulfate
40
a heteropolysaccharide used as plasma volume expander
Dextran
41
composed of N-acetylgalatosamine + L-iduronic acid present in skin, blood vessel, and heart valves
dermatan sulfate
42
composed of glucosamine + glucuronic acid or iduronic acid present in liver, lung, spleen, and anticoagulant
heparin
43
composed of N-acetylglucosamine + galactose present in cartilage, cornea, only glycosaminoglycan not having uronic acid
keratan sulfate
44
general formula of Monosaccharides
CnH2nOn
45
grouped together according to the number of carbons they contain
Monosaccharides
46
C3H6O3
Triose
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C4H8O4
Tetrose
48
C5H10O5
Pentose
49
C6H12O6
Hexose
50
C7H14O7
Heptose
51
C8H16O8
Octose
52
3 Classifications of Monosaccharides
Trioses
Pentoses
Hexoses
53
the parent member of the family of monosaccharides
Trioses
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from them emanates the other members of the monosaccharide
family.
Trioses
55
the final form of carbohydrate into which all carbohydrates,
regardless of their complexity, are degraded in the body during
carbohydrate metabolism.
Trioses
56
2 examples of Trioses
D - Glyceraldehyde
Dihydroxyacetone
57
an example of an aldotriose
D - Glyceraldehyde
58
an example of a ketotriose
Dihydroxyacetone
59
2 kinds of Pentoses
Ketopentoses
Aldopentoses
60
2 kinds of Ketopentoses
D-ribulose
D-xylulose
61
a key enzyme in both photosynthetic
carbon fixation and photorespiration
D-ribulose
62
used as a diabetic sweetener in food and
beverage
D-xylulose
63
2 kinds of Aldopentoses
D-lyxose
D-ribose
64
A constituent of lyxoflavin isolated from
human heart muscle
D-lyxose
65
composed of ribose and 2-deoxyribose
D-ribose
66
present as intermediates
in metabolic pathways and are important building
block of RNA and DNA
D-ribose
67
the most common of all the monosaccharides
Hexoses
68
2 kinds of Hexoses
Aldohexoses
Ketohexose
69
3 kinds of Aldohexoses
D-mannose
D-glucose
D-galactose
70
minor dietary sugar in humans;
D-mannose
71
used to help treat and prevent urinary tract infections (UTIs)
D-mannose
72
- A 5% (m/v) glucose solution is often
used in hospitals as an intravenous source of
nourishment for patients who cannot take food
by mouth.
D-glucose
73
a kind of Ketohexose
D-fructose
74
a sweetening agent
D-fructose
75
Monosaccharides can be classified based on their spatial orientation or ----
(stereochemistry).
76
A monosaccharide can be classified as a ----- or ---- isomer
D or L isomer
77
can be classified as a D or L isomer,
depending on the spatial orientation of the –H and –OH groups
attached to the carbon atom adjacent to the terminal primary
alcohol group.
monosaccharide
78
an isomer is represented when the –OH is written to
the right of this carbon in the Fischer projection formula.
D isomer
79
an isomer which is represented when this –OH is written to
the left.
L isomer
80
5 Biochemically Important Monosaccharides
Glucose
Fructose
Galactose
Ribose
Hemiacetals and Hemiketals
81
Most abundant in nature
Glucose
82
Nutritionally most important
Glucose
83
Grape fruit is an example of good source of glucose (20-30% by mass) - also named grape sugar, dextrose and blood sugar (70-100 mg/100
mL of blood)
Glucose
84
a six membered cyclic form
Glucose
85
Ketohexose
Fructose
86
the sweetest of all sugars; the fruit sugar
Fructose
87
Found in many fruits and in honey
Fructose
88
a Good dietary sugar-- due to highest sweetness
Fructose
89
a six membered cyclic form
glucose
galactose
90
A component of milk sugar
Galactose
91
Synthesized in human
Galactose
92
Also called brain sugar-- part of brain and
nerve tissue
Galactose
93
Used to differentiate between blood types
Galactose
94
Six membered cyclic form
Galactose
95
a result of genetic deficiency
in the infant – the gene responsible for the
enzyme that converts D-galactose to D-glucose.
Such infants cannot metabolize galactose and it
builds up in the blood and tissue.
Galactosemia
96
* Part of RNA
* Part of ATP
* Part of DNA
* Five membered cyclic form
Ribose
97
The dominant form of
monosaccharides with 5 or more C
atoms is
Hemiacetals and Hemiketals
98
The dominant form of
monosaccharides with 5 or more C
atoms is
cyclic
99
are formed from the reaction between two functional groups: aldehyde or ketone and alcohol
Hemiacetals and hemiketals
100
Hemiacetals and hemiketals are
formed from the reaction between
two functional groups which are:
aldehyde or ketone and alcohol
101
may take place either intermolecularly or intramolecularly as in the case of sugars
Hemiacetals and Hemiketals
102
provided there are sufficient number of carbons between the aldehyde or ketone and the alcohol group to permit a stable ring formation
Hemiacetals and Hemiketals
103
has a five- or six-membered
hemiacetal rings are stable
Hemiacetals and Hemiketals
104
Two types of ring structures are
possible for Hemiacetals and Hemiketals:
five-membered ring, or furanose ring
six-membered ring, or pyranose ring
105
derived from
parent compound furan
furanose ring
106
derived from
parent compound pyran
pyranose ring
107
two anomers of D-
glucose:
α-D- glucose & β-D-glucose
108
In the cyclic hemiacetals of glucose, -------, is now a chiral center (an anomeric carbon)
C1
109
are readily interconvertible in aqueous solution this interconversion of α- and β- anomers in solution is accompanied by a change in specific rotation called MUTAROTATION.
cyclic hemiacetals
110
The cyclic hemiacetals are readily interconvertible in
aqueous solution this interconversion of α- and β- anomers
in solution is accompanied by a change in specific rotation
called
MUTAROTATION
111
only sugars that form hemiacetal or hemiketal structure can ----
mutarotate
112
only sugars that can mutarotate
hemiacetal or hemiketal
113
2 anomeric forms of D-glucose
Alpha-form
Beta-form
114
-OH of C1
and CH2OH of C5 are
on opposite sides
Alpha-form
115
-OH of C1
and CH2OH of C5 are
on same sides
Beta-form
116
Cyclic monosaccharides that differ only in the position of the substituents on the anomeric carbon atom.
Anomers
117
Any — OH group at a chiral center that is to the right in a Fischer projection formula points
down in the Haworth projection formula
118
any — OH group to the
left in a Fischer projection
formula points
up in the Haworth projection formula
119
Fructose and other ketoses with a sufficient number of carbon atoms also
cyclize
120
Five important reactions of monosaccharides:
– Oxidation to acidic sugars
– Reduction to sugar alcohols
– Phosphate ester formation
– Amino sugar formation
– Glycoside formation
121
reactions of monosaccharides will be considered with respect to
glucose; other aldoses, as well as ketoses,
122
reactions are chemical reactions involving the
transfer of electrons between two substances.
REDOX REACTIONS
123
REDOX REACTIONS encompass two complementary processes
oxidation and reduction
124
is the process in which a substance loses electrons
Oxidation
125
*In cellular respiration, glucose undergoes oxidation to produce
carbon dioxide
126
is the process in which a substance gains
electrons
Reduction
127
*In photosynthesis, carbon dioxide is reduced to form
glucose
128
*During cellular respiration, oxygen is reduced to form
water
129
is a substance that accepts electrons and gets
reduced in the process
oxidizing agent
130
is a substance that donates electrons and gets
oxidized in the process
reducing agent
131
Facilitates reduction by being oxidized itself.
Reducing Agent
132
Facilitates oxidation by being reduced itself.
oxidizing agent
133
Gives three different types of acidic sugars depending
on the type of oxidizing agent used
Oxidation
134
3 types of oxidizing agents
Weak oxidizing agents
Strong oxidizing agents
biochemical systems enzymes
135
Weak oxidizing agents like Tollens and Benedict’s
solutions oxidize the aldehyde end to give an
aldonic acid
136
Strong oxidizing agents can oxidize both ends of a
monosaccharide at the same time to produce
aldaric acid
137
like Tollens and Benedict’s solutions oxidize the aldehyde end to give an aldonic acid.
Weak oxidizing agents
138
can oxidize both ends of a monosaccharide at the same time to produce aldaric acid.
Strong oxidizing agents
139
In biochemical systems enzymes can oxidize the
primary alcohol end of an aldose such as glucose,
without oxidation of the aldehyde group, to produce
an
alduronic acid
140
can oxidize the primary alcohol end of an aldose such as glucose, without oxidation of the aldehyde group, to produce an alduronic acid.
biochemical systems enzymes
141
is reduced to a hydroxyl group using
hydrogen as the reducing agent.
Reduction
142
product of The carbonyl group in a monosaccharide (either an aldose or a ketose) is reduced to a hydroxyl group using hydrogen as the reducing agent.
polyhydroxy alcohol sugar alcohol
143
used as moisturizing agents in
foods and cosmetics and as a sweetening agent in chewing
gum
Sorbitol (glucitol)
144
Under prescribed conditions, some sugars reduce silver
ions to free silver and copper(II) ions to copper(I) ions.
Such sugars are called
reducing sugars
145
reducing sugar will have one of the following groups.
an aldehyde group
a hydroxyketone
a cyclic hemiacetal group
146
(as in glyceraldehyde)
an aldehyde group
147
(as in fructose)
a hydroxyketone
148
(as in glucose and maltose)
cyclic hemiacetal group
149
3 tets that are based on the formation of a brick red copper(I) oxide precipitate as a positive result
Benedict, Barfoed, and Fehling tests
150
is based on the
formation of a silver mirror.
Tollens test
151
is more sensitive in that it can distinguish
a reducing monosaccharide from a reducing disaccharide.
Barfoed test
152
Sugars with the hemiacetal structure can be
Reducing sugars
153
Sugars with the hemiacetal structure can be reducing sugars under alkaline conditions because the ring opens forming an
aldehyde group
154
The hydroxyl groups of a monosaccharide can react with
inorganic oxyacids to form inorganic
esters
155
are stable in aqueous
solution and play important roles in the pentose-phosphate
pathway, glycolysis, and gluconeogenesis.
Phosphate esters
156
One of the hydroxyl groups of a monosaccharide is replaced with an amino group
Amino Sugar Formation
157
it is when the hydroxyl groups of a monosaccharide can react with inorganic oxyacids to form inorganic esters.
Phosphate Ester Formation
158
In naturally occurring amino sugars the carbon 2 hydroxyl group is replaced by an amino group
Amino Sugar Formation
159
in amino sugar formation ------------- are important building
blocks of polysaccharides such as chitin and hyaluronic acid
Amino sugars and their N- acetyl derivatives
160
which are fundamental components of various joint
structures, including ligaments, tendons, cartilage, and synovial
fluid.
glycosaminoglycans and glycoproteins
161
consist of an amino sugar and a uronic sugar
Glycoaminoglycans
162
molecules due to the presence of sulfate and carboxyl groups, which attract water and give them their gel-like properties.
Glycoaminoglycans
163
has a structural role in connective tissues providing integrity, resilience and resistance to compression
Glycoaminoglycans
164
it is when the cyclic forms of monosaccharides, the hemiacetals, react with alcohols to form acetals
Glycoside Formation
165
is an acetal formed from a cyclic monosaccharide by replacement of the hemiacetal carbon — OH group with an — OR group to form a double ether
glycoside
166
produced from glucose – glucoside and from
galactose – galactoside
glycoside
167
converts various hydrophobic drugs and toxins into hydrophilic
glycosides (e.g., glucuronides) to enhance their solubility and facilitate their excretion through urine or bile.
liver
168
is a crucial detoxification pathway in
the body
glycosylation
169
is an aldohexose and the most monosaccharide
D-Glucose
170
known as blood sugar
D-Glucose
171
differs structurally from glucose in the orientation of the carbon-4 hydroxyl group
D-Galactose
172
also known as brain sugar
D-Galactose
173
a ketohexose and is structurally identical to glucose from carbon-3 to carbon carbon-6
D-Fructose
174
also known as fruit sugar
D-Fructose
175
is a aldopentose and its structure is that of glucose with carbon-3 removed
D-Ribose
176
is an important in nucleic acid chemistry
D-Ribose
177
sugars obtained by oxidation
acidic sugars
178
3 examples of acidic sugars
aldonic acid
alduronic acid
aldaric acid
179
it is when the acid group is on top
aldonic acid
180
it is when the acid group is on bottom
alduronic acid
181
it is when the acid groups is on both top and bottom
aldaric acid
182
this is a sugar obtained by reduction
alditol
183
it is when alcohol groups on both top and bottom
alditol
184
2 compounds with a five-membered ring in its cyclic form
Fructose
RIbose
185
Its cyclic form has two carbon atoms outside the ring.
fructose
