Carbohydrates Pt. 2 Flashcards
1
Q
Most of the matter in plants, except water, is
A
carbohydrate material
2
Q
Carbohydrates account for ________________ and are produced by photosynthesis.
A
75% of dry plant material
3
Q
structural element
A
Cellulose
4
Q
energy reservoir
A
Starch/glycogen
5
Q
small amount in human body
A
Starch/glycogen
6
Q
are source of carbohydrates
A
Plant products
7
Q
Average human diet contains
A
2/3 of carbohydrates
8
Q
a sugar or cybohydrate that acts as an important energy store for the body
A
glycogen
9
Q
Functions of Carbohydrates in the Human Body
A
- Carbohydrate oxidation - provides energy
- Carbohydrate storage, in the form of glycogen, provides a short-term energy reserve.
- Carbohydrates supply carbon atoms for the synthesis of other biochemical substances (proteins, lipids, and nucleic acids)
- Carbohydrates form part of the structural framework of DNA and RNA molecules
- Carbohydrates linked to lipids are structural components of cell membranes
- Carbohydrates linked to proteins function in a variety of cell–cell and cell–molecule recognition processes
10
Q
Simpler Formula for Carbohydrates
A
CnH2nOn or Cn(H2O)n
11
Q
are polyhydroxy aldehydes or ketones or compounds that produce such substances upon hydrolysis.
A
Carbohydrates
12
Q
Carbohydrates are ________________________________ or compounds that produce such substances upon hydrolysis.
A
polyhydroxy aldehydes or ketones
13
Q
3 carbon atoms
A
Triose
14
Q
4 carbon atoms
A
Tetrose
15
Q
5 carbon atoms
A
Pentoses
16
Q
6 carbon atoms
A
Hexoses
17
Q
Monosaccharides with one aldehyde group
A
Aldoses
18
Q
Monosaccharides with one ketone group
A
Ketoses
19
Q
Contain single polyhydroxy aldehyde or ketone unit
A
Monosaccharide
20
Q
They can’t be broken down into simpler substances by
hydrolysis (reaction with water) reactions
A
Monosaccharide
21
Q
Monosaccharide contains how many carbon atoms?
A
3-7
22
Q
Water soluble white crystalline solids
A
Monosaccharide
23
Q
examples of Monosaccharide
A
Glucose and fructose
24
Q
Examples of Triose
A
Glyceraldehyde and Dihydroxyacetone
25
Example of Tetroses
Erythrose, Threose and Erythrulose
26
Examples of Pentoses - Aldopentoses
Ribose, Arabinose, Xylose, Lyxose
27
Examples of Pentoses - Ketopentoses
Ribulose and Xylulose
28
Examples of Hexoses - Aldohexose
Allose, Altrose, Glucose, Mannose, Gulose, Idose, Glactose, Talose
29
Examples of Hexoses - Ketohexose
Psicose, Fructose, Surbose, Tagatose
30
Most Common Monosaccharides
Aldohexose, Ketohexose
31
Monosaccharide with aldehyde group and 6 C atoms – D-glucose
Aldohexose
32
Monosaccharide with ketone group and 6 C atoms – D-fructose
Ketohexose
33
Biochemically Important Monosaccharides
D-glyceraldehyde, Dihydroxyacetone, D-glucose, D-galactose, D-frustose, D-ribose
34
Glucose and glactose are
aldohexose
35
fructose is a
ketohexose
36
ribose is a
aldopentose
37
Most abundant in nature
Glucose
38
Nutritionally most important
Glucose
39
good source of glucose
grape fruit, dextrose and blood sugar
40
Glucose has how many ring members in cyclic form?
Six membered cyclic form
41
1. Most abundant in nature
2. Nutritionally most important
3. Grape fruit good source of glucose (20 - 30% by mass) -- also named grape sugar, dextrose and blood sugar (70 - 100 mg/100 mL of blood)
4. Six membered cyclic form
Glucose
42
1. Ketohexose
2. Sweetest tasting of all sugars
3. Found in many fruits and in honey
4. Good dietary sugar-- due to higher sweetness
5. Five membered cyclic form
Fructose
43
Found in many fruits and in honey
Fructose
44
Good dietary sugar-- due to higher sweetness
Fructose
45
Fructose has how many rings?
Five membered cyclic form
46
the natural sugar found in fruits is
fructose
47
1. Milk sugar
2. Synthesize in human
Galactose
48
Also called brain sugar-- part of brain and nerve tissue
Galactose
49
Used to differentiate between blood types
Galactose
50
Galactose has how many ring members in cyclic form?
Six membered cyclic form
51
1. Part of RNA
2. Part of ATP
3. Part of DNA
4. Five membered cyclic form
Ribose
52
Ribose has how many ring members in cyclic form?
Five membered cyclic form
53
2 forms of D-glucose
Alpha-form and Beta-form
54
-OH of C1 and CH2OH of C5 are on opposite sides
Alpha-form
55
-OH of C1 and CH2OH of C5 are on same sides
Beta-form
56
Cyclic monosaccharides that differ only in the position of the substituents on the anomeric carbon atom
Anomers
57
Alpha or Beta configuration is determined by
the position of the — OH group on C1 relative to the CH2OH group that determines D or L series.
58
both of these groups point in the same direction
Beta configuration
59
the two groups point in opposite directions
Alpha configuration
60
is a twodimensional structural notation that specifies the three-dimensional structure of a cyclic form of a monosaccharide.
Haworth projection formula
61
The specific identity of a monosaccharide is determined by the
positioning of the other —OH groups in the Haworth projection formula.
62
A cyclic monosaccharide containing a six-atom ring is called a
pyranose
63
and one containing a five-atom ring is called
furanose
64
Contains 2 monosaccharide units covalently bonded to each other.
Disaccharides
65
are crystalline and water soluble substances
Disaccharides
66
are common disaccharides
Table sugar (sucrose) and milk sugar (lactose)
67
Two monosaccharides can react to form a
disaccharide
68
One monosaccharide act as a hemiacetal and other as alcohol and the resulting ether bond is a
glycosidic linkage
69
Maltose also known as
malt sugar
70
made of 2 alpha-D-glucose units linked via an alpha 1->4 linkage
Maltose
71
is digested easily by humans because we have enzymes that can break alpha (1->4) linkages but not beta (1->4) linkages of cellobiose. Therefore cellobiose cannot be digested by humans.
Maltose
72
are rich in maltose
Baby foods
73
is produced as an intermediate in the hydrolysis of the polysaccharide cellulose
Cellobiose
74
contains two beta - D-glucose monosaccharide units linked through a beta (1->4) glycosidic linkage.
Cellobiose
75
is made up of beta-D-galactose unit and a betaD-glucose unit joined by a beta (1->4) glycosidic linkage
Lactose
76
is rich in lactose disaccharide
Milk
77
the natural sugar found in milk is
galactose
78
galactose =
glucose + galactose
79
principal carbohydrate in milk
lactose
80
percentage of lactose in human
7%-8%
81
percentage of lactose in cow's milk
4%-5%
82
a condition in which people lack the enzyme lactase needed to hydrolyze lactose to galactose and glucose.
Lactose intolerance
83
hydrolyzes beta (1->4) glycosidic linkages.
lactase
84
The most abundant of all disaccharides and found in plants.
sucrose
85
sucrose is produced commercially from the juice of
sugar cane and sugar beets
86
contains up to 20% by mass sucrose
sugar cane
87
contain up to 17% by mass sucrose
sugar beets
88
Contains 3-10 monosaccharide units - covalently bonded to each other
Oligosaccharides
89
Usually found associated with proteins and lipids in complex molecules.
– Serve structural and regulatory functions
Oligosaccharides
90
Carbohydrates that contain 3-10 monosaccharide units bonded to each other via glycosidic linkages.
Oligosaccharides
91
Examples of Polysaccharide
Raffinose and Stachyose
92
made of one each of galactose, glucose and fructose
Raffinose
93
made of 2 galactose, 1 glucose and 1 fructose units
Stachyose
94
Raffinose and stachyose
Commonly found in onions, cabbage, broccoli and wheat
95
can break them down and thus prevent gas after eating beans is available as an over-the-counter supplement
alpha-galactosidase
96
Human blood is classified into four types:
A, B, AB, and O blood groups
97
are universal donors
people with type O blood
98
AB blood
are universal recipients
99
The oligosaccharides responsible for blood groups are
D-galactose and its derivatives
100
a potato toxin, is a oligosaccharide found in association with an alkaloid
Solanin
101
Bitter taste of potatoes is due to relatively higher levels of
solanin
102
Contains many monosaccharide units covalently bonded
Polysaccharides
103
May contain a few 100s to > million monosaccharide units
Polymers
104
Examples of Polysaccharides
- Cellulose: Paper, cotton, wood
- Starch: Bread, pasta, potatoes, rice, corn, beans, peas, etc.
105
Polymers of many monosaccharide units bonded with glycosidic linkages
Polymer Chain
106
Two types of polymer chain
Linear and branched, homo- and heteropolysaccharides
107
are not sweet and don’t show positive tests with Tollen’s and Benedict’s solutions whereas monosaccharides are sweet and show positive tests
Polysaccharides
108
Examples of Polysaccharides pt. 2
– Cellulose, starch in plants
– Glycogen in animals
– Chitin in arthropods
109
is a polysaccharide that is a storage form for monosaccharides and is used as an energy source in cells
Starch/storage polysscharides
110
- Glucose is the monomeric unit
– Storage polysaccharide in plants
starch
111
Two types of polysaccharides isolated from starch
amylose and amylopectin
112
Straight chain polymer - 15 - 20% of the starch and has alpha (1 ->4) glycosidic bonds
amylose
113
Branched chain polymer - 80 - 85 % of the starch alpha (1->4) glycosidic bond for straight chain and alpha (1->6) for branch
amylopectin
114
- Human and animal storage polysaccharide
– Contains only glucose units
Glycogen
115
– Three times more highly branched than amylopectin in
starch
– Excess glucose in blood stored in the form of glycogen
Glycogen
116
Branched chain polymer – alpha (1->4) glycosidic bonds in straight chains and alpha (1->6) in branches
Amylopectin
117
- Up to 5000 glucose units with molecular mass of ~900,000 amu
– Cotton ~95% cellulose and wood ~50% cellulose
– Humans don’t have enzymes that hydrolyze beta (14) linkages -so they can not digest cellulose -- animals also lack these enzymes but they can digest cellulose because they have bacteria in their guts to hydrolyze cellulose
– It serves as dietary fiber in food-- readily absorbs water and results in softer stools
– 20 - 35 g of dietary fiber is desired everyday
Cellulose
118
– Similar to cellulose in both function and structure
– Linear polymer with all beta (14) glycosidic linkages - it has a Nacetyl amino derivative of glucose
– Function is to give rigidity to the exoskeletons of crabs, lobsters, shrimp, insects, and other arthropods
Chitin
119
polysaccharides with a repeating disaccharide unit containing an amino sugar and a sugar with a negative charge due to a sulfate or a carboxyl group.
Acidic polysaccharides
120
present in connective tissue associated with joints, cartilage, synovial fluids in animals and humans
Structural polysaccharide
121
– Alternating residues of Nacetyl-beta-D-glucosamine and D
-glucuronic acid.
– Highly viscous - serve as lubricants in the fluid of joints and part of vitreous humor of the eye.
Hyaluronic acid
122
– An anticoagulant prevents blood clots.
– Polysaccharide with 15 - 90 disaccharide residues per chain.
Heparin
123
is a lipid molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it.
glycolipid
124
is a protein molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it
glycoprotein
125
Foods high in carbohydrate content constitute over_________ of the diet of most people of the world -- a balanced dietary food should contain about ________ of carbohydrate:
50%; 60%
126
Nutritionists divide dietary carbohydrates into two classes:
Simple carbohydrates and Complex carbohydrates
127
dietary monosaccharides or disaccharides - sweet to taste commonly referred to as sugars - 20 % of the energy in the US diet
Simple carbohydrates
128
Dietary polysaccharides -- starch and cellulose - normally not sweet to taste
Complex carbohydrates
129
Glycemic effect refers to
– how quickly carbohydrates are digested
– how high blood glucose rises
– how quickly blood glucose levels return to normal
130
has been developed for rating foods
Glycemic index (GI)
