Question Of Carbohydrate كتاب الطويل Flashcards
(175 cards)
1
Q
What are carbohydrates?
A
Organic substances composed of carbon, hydrogen, and oxygen
Carbohydrates can also be defined as simple sugars (polyhydroxy aldehydes or ketones) or their derivatives.
2
Q
What are the two main types of monosaccharides based on their functional groups?
A
- Aldoses
- Ketoses
Aldoses contain an aldehyde group (-CHO), while ketoses contain a ketone group (-C=O).
3
Q
How are carbohydrates classified according to hydrolysis products?
A
- Monosaccharides
- Disaccharides
- Oligosaccharides
- Polysaccharides
Monosaccharides contain 1 sugar unit, disaccharides contain 2, oligosaccharides contain 3-10, and polysaccharides contain more than 10 sugar units.
4
Q
What is the general formula for monosaccharides?
A
Cn(H2O)n
This formula indicates that monosaccharides are the simplest units of carbohydrates.
5
Q
What are the categories of monosaccharides based on the number of carbon atoms?
A
- Trioses (3 carbons)
- Tetroses (4 carbons)
- Pentoses (5 carbons)
- Hexoses (6 carbons)
Each category also includes specific types such as aldotrioses, ketotrioses, etc.
6
Q
Fill in the blank: Monosaccharides are the simplest units of carbohydrate containing _______ sugar unit.
A
one
Monosaccharides cannot be hydrolyzed into simpler sugars.
7
Q
True or False: The typical ratio of carbon to water in carbohydrates is 1:2.
A
False
The typical ratio is 1:1, hence the name carbohydrate.
8
Q
What is the classification of carbohydrates based on the number of sugar units?
A
- Monosaccharides
- Disaccharides
- Oligosaccharides
- Polysaccharides
This classification reflects the complexity of the carbohydrate structure.
9
Q
What are monosaccharides containing 3 carbons called?
A
Trioses
Examples include aldotrioses (Glyceraldehyde) and ketotrioses (Dihydroxyacetone)
10
Q
Name an example of an aldotriose.
A
Glyceraldehyde
Also referred to as glycerose
11
Q
What is the ketotriose example?
A
Dihydroxyacetone
A simple ketone that is a triose
12
Q
What are monosaccharides containing 4 carbon atoms called?
A
Tetroses
The suffix —ulose indicates a keto group
13
Q
Provide an example of a tetrose.
A
D-Erythrose
Another example is D-Erythrulose
14
Q
What monosaccharides contain 5 carbon atoms?
A
Pentoses
Include aldo- and keto-pentoses
15
Q
Name two examples of aldo-pentoses.
A
Ribose, arabinose
Other examples include xylose and lyxose
16
Q
What are the examples of keto-pentoses?
A
Ribulose, xylulose
Both are forms of pentoses
17
Q
What are the functions of ribose?
A
- Structure of nucleic acids (RNA and DNA)
- Structure of ATP, GTP
- Structure of coenzymes NAD, NADP, and FAD
Ribose is crucial for energy transfer and genetic information
18
Q
What are monosaccharides containing 6 carbon atoms called?
A
Hexoses
They include both aldohexoses and ketohexoses
19
Q
List examples of aldohexoses.
A
- Glucose
- Mannose
- Galactose
These are important sugars in metabolism
20
Q
What is the example of a ketohexose?
A
Fructose
A common sugar found in many plants
21
Q
What is the main sugar found in blood?
A
Glucose
Glucose is also referred to as ‘grape sugar’ and is a major source of energy in the body.
22
Q
What is the primary function of glucose in the body?
A
It serves as a major source of energy.
Glucose is converted to all carbohydrates in the body, such as glycogen and galactose.
23
Q
What sugar is synthesized in the mammary gland to make lactose?
A
Galactose
Galactose can also be converted into glucose in the liver.
24
Q
What is fructose commonly known as?
A
Fruit sugar
Fructose is the main sugar found in semen.
25
What is mannose a constituent of?
Many glycoproteins
## Footnote
Mannose plays a role in various biological processes.
26
What type of sugar structure is formed through a reaction between the carbonyl group and an alcoholic hydroxyl group?
Cyclic structure
## Footnote
This reaction leads to the formation of furanose and pyranose structures.
27
What is a furanose structure?
A 4 Carbon ring
## Footnote
The furanose form resembles the organic compound called furan.
28
What is a pyranose structure?
A 5 Carbon ring
## Footnote
The pyranose form resembles the organic compound called pyran.
29
If the remaining hydroxyl group is on the right side, what type of sugar is it?
α-sugar
## Footnote
Conversely, if the remaining hydroxyl group is on the left side, it is a β-sugar.
30
What are the two types of cyclic sugar structures?
* Furanose
* Pyranose
## Footnote
These structures differ based on the number of carbons in the ring.
31
What are the two forms in which the cyclic structure of sugars may be present?
Haworth and chair forms
## Footnote
These forms represent different ways of depicting the cyclic structure of sugars.
32
In the Haworth formula, how are the -OH groups positioned?
All -OH groups on the right side are written downwards; all -OH groups on the left side are written upwards
## Footnote
This positioning helps in visualizing the stereochemistry of the sugar.
33
What is an asymmetric carbon atom?
A carbon atom to which 4 different groups or atoms are attached
## Footnote
Asymmetric carbon atoms are crucial for determining the optical activity of substances.
34
What properties do substances containing asymmetric carbon atoms exhibit?
* Optical activity
* Optical isomerism
## Footnote
These properties are important in the study of stereochemistry.
35
What is optical activity?
The ability of a substance to rotate plane polarized light either to the right or to the left
## Footnote
This characteristic is significant in distinguishing between different isomers.
36
If a substance rotates plane polarized light to the right, what is it called?
Dextrorotatory or d or (+)
## Footnote
This indicates a specific type of optical activity.
37
If a substance rotates plane polarized light to the left, what is it called?
Levorotatory or l or (-)
## Footnote
This indicates the opposite type of optical activity.
38
How many asymmetric carbon atoms does glucose contain?
4
## Footnote
This contributes to glucose's optical activity.
39
What is glucose sometimes referred to as due to its dextrorotatory nature?
Dextrose
## Footnote
This name reflects its ability to rotate light to the right.
40
How many asymmetric carbon atoms does fructose contain?
3
## Footnote
This structural characteristic affects its optical activity.
41
What is fructose sometimes called due to its levorotatory nature?
Levulose
## Footnote
This name indicates its ability to rotate light to the left.
42
Fill in the blank: The straight chain form of D-Glucose is represented as _______.
D-Glucose
## Footnote
This is the open-chain structure of glucose.
43
What is optical isomerism?
The ability of a substance to present in more than one form (isomer).
44
How many isomers does a substance with one asymmetric carbon atom have?
2 isomers.
45
What is the simplest carbohydrate that has one asymmetric carbon atom?
Glyceraldehyde.
46
What are the two optically active forms of Glyceraldehyde?
* L-Glyceraldehyde
* D-Glyceraldehyde
47
What is an anomeric carbon?
The asymmetric carbon atom obtained from the active carbonyl sugar group.
48
In aldoses, which carbon is considered the anomeric carbon?
C1.
49
In ketoses, which carbon is considered the anomeric carbon?
C2.
50
What are anomers?
Isomers obtained from the change of position of the hydroxyl group attached to the anomeric carbon.
51
Give an example of two anomers.
* α-D-Glucose
* β-D-Glucose
52
What is the difference between aldose and ketose isomerism?
They have the same molecular formula but differ in functional group.
53
Provide an example of aldose-ketose isomerism.
Fructose (ketone group) & Glucose (aldehyde group).
54
What are epimers?
Isomers having more than one asymmetric carbon, differing only at one carbon.
55
Which carbons differentiate glucose and mannose?
Carbons 2.
56
Which carbons differentiate glucose and galactose?
Carbons 4.
57
True or False: Epimers are isomers that differ at more than one asymmetric carbon.
False.
58
Fill in the blank: The anomeric carbon in aldoses is at ______.
C1.
59
Fill in the blank: The anomeric carbon in ketoses is at ______.
C2.
60
What are sugar acids produced by?
Oxidation of carbonyl carbon, last carbon, or both
## Footnote
Sugar acids include aldonic acids, uronic acids, and aldaric acids.
61
What is an example of an aldonic acid?
Glucose
## Footnote
Aldonic acids are derived from the carbonyl carbon.
62
What is an example of a uronic acid?
Glucuronic acid
## Footnote
Uronic acids are derived from the last hydroxyl carbon.
63
What are aldaric acids produced from?
Both carbonyl and last hydroxyl carbons
## Footnote
An example is glucaric acid.
64
What is L-Ascorbic acid commonly known as?
Vitamin C
## Footnote
It is an important sugar acid.
65
How are sugar alcohols produced?
Reduction of carbonyl carbon
## Footnote
Sugar alcohols include sorbitol and mannitol.
66
What is an example of a sugar alcohol derived from glucose?
Sorbitol
## Footnote
Other examples include mannitol and dulcitol.
67
What are deoxysugars characterized by?
Replacement of hydroxyl groups by hydrogen atoms
## Footnote
This results in missing oxygen.
68
What is an example of a deoxysugar found in nucleic acid?
Deoxyribose
## Footnote
It is a component of DNA.
69
What is L-Fucose also known as?
6-deoxy-L-galactose
## Footnote
It is involved in blood group antigen structures.
70
What are amino sugars characterized by?
Replacement of hydroxyl group on C2 by an amino or acetyl-amino group
## Footnote
They are components of glycoproteins.
71
What is an example of an amino sugar?
Glucosamine
## Footnote
It is found in heparin and hyaluronic acid.
72
Fill in the blank: Sugar acids are produced by _______.
oxidation
## Footnote
This includes various types of sugar acids.
73
True or False: Sugar alcohols are produced by oxidation.
False
## Footnote
Sugar alcohols are produced by the reduction of carbonyl carbon.
74
What are the three types of sugar derivatives mentioned?
* Sugar acids
* Sugar alcohols
* Deoxysugars
* Amino sugars
## Footnote
These derivatives play various roles in biological systems.
75
What is galactosamine's role in biochemistry?
It enters in chondroitin sulphate.
## Footnote
Galactosamine is an amino sugar that contributes to the structure of glycosaminoglycans.
76
What does mannosamine contribute to in biochemical pathways?
It enters in neuraminic and sialic acids.
## Footnote
Mannosamine is important for the synthesis of sialic acids, which are involved in cellular recognition.
77
Define amino sugar acids.
Formed by addition of amino sugars and some acids.
## Footnote
Amino sugar acids are crucial in various biological processes, including the formation of glycoproteins.
78
Give an example of an amino sugar acid and its components.
Neuraminic acid = Mannosamine + pyruvic acid.
## Footnote
Neuraminic acid is a key component of sialic acids, which play a role in cell signaling.
79
What is N-acetylneuraminic acid (NANA) commonly referred to as?
Sialic acid.
## Footnote
NANA is a derivative of neuraminic acid and is found in various glycoconjugates.
80
What is a glycosidic bond?
The bond between a carbohydrate and another compound to form a complex carbohydrate.
## Footnote
Glycosidic bonds are vital for the formation of disaccharides and polysaccharides.
81
What types of compounds can form a glycosidic bond?
Another monosaccharide or a glycone (non-carbohydrate).
## Footnote
This versatility allows for the creation of various complex carbohydrates.
82
What are N and O-glycoside bonds?
Types of glycosidic bonds formed with nitrogen and oxygen respectively.
## Footnote
These bonds are important in the structure of nucleotides and glycoproteins.
83
What are sugar nucleotides?
Examples include ATP, GP, and other nucleotides with purines and pyrimidines as aglycone.
## Footnote
Sugar nucleotides play key roles in metabolism and energy transfer.
84
What is a characteristic of cardiac glycosides?
Aglycone is steroid.
## Footnote
Cardiac glycosides are used in treating heart diseases due to their ability to increase cardiac output.
85
Which of the following is NOT a sugar alcohol? a) Galactitol b) Mannitol c) Xylulose d) Sorbitol
c) Xylulose.
## Footnote
Xylulose is a ketopentose sugar, not a sugar alcohol.
86
Ribitol is classified as what type of sugar?
Sugar alcohol.
## Footnote
Ribitol is a polyol and is important in the structure of certain nucleotides.
87
Sorbitol is produced by the reduction of _______.
Glucose or fructose.
## Footnote
Sorbitol is used as a sugar substitute and has applications in medicine.
88
What are the two main components of trehalose?
a-glucose + a-glucose
## Footnote
Trehalose is formed by a (1-1) glycosidic bond.
89
What type of glycosidic bond is found in maltose?
a (1-4) glycosidic bond
## Footnote
Maltose is composed of two a-glucose units.
90
What type of glycosidic bond is found in isomaltose?
a (1-6) glycosidic bond
## Footnote
Isomaltose is produced during digestion of starch and glycogen by amylase.
91
What are the components of sucrose?
a-glucose + B-fructose
## Footnote
Sucrose has an (a1-ß2) glycosidic bond.
92
What are the components of lactose?
ß-glucose + B-galactose
## Footnote
Lactose is formed by a B (1-4) galactosidic bond.
93
Which disaccharides are reducing agents?
Maltose, Isomaltose, Lactose
## Footnote
Trehalose and sucrose do not show reducing properties.
94
Which disaccharides can form characteristic osazone crystals?
Maltose, Isomaltose, Lactose
## Footnote
Sucrose and trehalose do not form osazone crystals.
95
What is invert sugar?
Sugar containing equal numbers of glucose and fructose molecules (unbound)
## Footnote
Invert sugar is derived from hydrolysis of sucrose.
96
What is the structure of invert sugar?
Equal number of glucose and fructose molecules
## Footnote
Invert sugar is levorotatory due to fructose's strong levorotatory effect.
97
What are common sources of maltose?
Malt, produced during digestion of starch
## Footnote
Amylase enzyme facilitates the production of maltose.
98
What are the sources of isomaltose?
Produced during digestion of starch and glycogen
## Footnote
Isomaltose is also a product of amylase activity.
99
What is a non-fermentable sugar?
Lactose
## Footnote
Lactose does not ferment easily compared to other sugars.
100
What are common sources of sucrose?
Sugarcane, sugar beet, pineapple, carrot
## Footnote
Sucrose is commonly known as table sugar.
101
Fill in the blank: Maltose is produced during digestion of starch by _______.
amylase enzyme
## Footnote
Amylase breaks down starch into maltose.
102
What are the two main components of trehalose?
a-glucose + a-glucose
## Footnote
Trehalose is formed by a (1-1) glycosidic bond.
103
What type of glycosidic bond is found in maltose?
a (1-4) glycosidic bond
## Footnote
Maltose is composed of two a-glucose units.
104
What type of glycosidic bond is found in isomaltose?
a (1-6) glycosidic bond
## Footnote
Isomaltose is produced during digestion of starch and glycogen by amylase.
105
What are the components of sucrose?
a-glucose + B-fructose
## Footnote
Sucrose has an (a1-ß2) glycosidic bond.
106
What are the components of lactose?
ß-glucose + B-galactose
## Footnote
Lactose is formed by a B (1-4) galactosidic bond.
107
Which disaccharides are reducing agents?
Maltose, Isomaltose, Lactose
## Footnote
Trehalose and sucrose do not show reducing properties.
108
Which disaccharides can form characteristic osazone crystals?
Maltose, Isomaltose, Lactose
## Footnote
Sucrose and trehalose do not form osazone crystals.
109
What is invert sugar?
Sugar containing equal numbers of glucose and fructose molecules (unbound)
## Footnote
Invert sugar is derived from hydrolysis of sucrose.
110
What is the structure of invert sugar?
Equal number of glucose and fructose molecules
## Footnote
Invert sugar is levorotatory due to fructose's strong levorotatory effect.
111
What are common sources of maltose?
Malt, produced during digestion of starch
## Footnote
Amylase enzyme facilitates the production of maltose.
112
What are the sources of isomaltose?
Produced during digestion of starch and glycogen
## Footnote
Isomaltose is also a product of amylase activity.
113
What is a non-fermentable sugar?
Lactose
## Footnote
Lactose does not ferment easily compared to other sugars.
114
What are common sources of sucrose?
Sugarcane, sugar beet, pineapple, carrot
## Footnote
Sucrose is commonly known as table sugar.
115
Fill in the blank: Maltose is produced during digestion of starch by _______.
amylase enzyme
## Footnote
Amylase breaks down starch into maltose.
116
What are polysaccharides?
Polymers of more than 10 units of monosaccharides or their derivatives
## Footnote
Includes aminosugars and uronic acids.
117
What are homopolysaccharides?
Polysaccharides containing 1 type of monosaccharide
## Footnote
Examples include glucans and fructans.
118
What are some examples of glucans?
* Starch
* Dextrin
* Glycogen
* Cellulose
## Footnote
All consist of D-glucose units.
119
What are heteropolysaccharides?
Polysaccharides containing more than 1 type of monosaccharide
## Footnote
Includes glycosaminoglycans.
120
What are glycosaminoglycans?
Mucopolysaccharides that can be sulfate-free or sulfate-containing
## Footnote
Examples include hyaluronic acid and chondroitin sulfate.
121
Fill in the blank: Inulin is a type of _______.
[heteropolysaccharide]
122
What are sulfate-containing glycosaminoglycans?
* Chondroitin S
* Dermatan S
* Keratan S
* Heparin
* Heparan S
## Footnote
These are important components in various biological processes.
123
What is the inner layer of a starch granule called?
Amylose
## Footnote
Amylose constitutes 15-20% of the starch granule and is found in cereals, potatoes, legumes, and other vegetables.
124
What color does starch give with iodine?
Blue
## Footnote
Starch gives a blue color with iodine, while amylopectin gives a red color.
125
What enzyme partially digests starch?
Amylase
## Footnote
Partial digestion by amylase enzyme produces various forms of dextrins.
126
What is the outer layer of a starch granule called?
Amylopectin
## Footnote
Amylopectin constitutes 80-85% of the starch granule and is formed of branched chains.
127
How many glucose units are typically in each chain of amylopectin?
24-30
## Footnote
Each chain in amylopectin is composed of 24-30 glucose units linked by 1-4 glycosidic bonds and 1-6 glycosidic bonds at branching points.
128
What are three types of dextrins produced from starch hydrolysis?
Amylodextrin, erythrodextrin, achrodextrin
## Footnote
These dextrins give a red color with iodine.
129
What is glycogen and its function?
Storage form of carbohydrates in humans and animals
## Footnote
Glycogen is highly branched and gives a reddish violet color with iodine.
130
What is the primary structure of cellulose?
Long linear chains of (B-D-glucopyranose)
## Footnote
Cellulose is linked together by β 1-4 glycosidic bonds.
131
What is one dietary benefit of cellulose?
Increases the bulk of stool
## Footnote
This helps stimulate intestinal movement and prevents constipation.
132
What color does cellulose give with iodine?
No color
## Footnote
Cellulose is insoluble in water and cannot be digested due to the absence of digestive hydrolase enzymes.
133
What is inulin made of?
Repeated units of fructose
## Footnote
These are linked together by 1-2 bonds and are found in the root of artichokes and other plants.
134
What is one use of inulin in medical diagnostics?
Investigation of GFR
## Footnote
Inulin clearance is used in diagnostic tests for assessing glomerular filtration rate.
135
What are glycosaminoglycans (GAGs)?
They are heteropolysaccharides formed of repeating disaccharide units
## Footnote
GAGs include components like acidic sugars and amino sugars
136
What are the two types of sugars that make up GAGs?
Acidic sugar and amino sugar
## Footnote
Acidic sugar can be D-glucuronic acid or L-iduronic acid; amino sugar can be D-glucosamine or D-galactosamine
137
What characterizes the acidic sugar in GAGs?
It is either D-glucuronic acid or L-iduronic acid
## Footnote
These sugars contribute to the overall structure of GAGs
138
What is the common modification found in amino sugars of GAGs?
The amino group is usually acetylated
## Footnote
Amino sugars may also be sulfated at carbon 4 or 6
139
What charge do GAGs typically have?
They are very negatively charged due to uronic acid and sulfate residues
## Footnote
This negative charge influences their interactions with other molecules
140
Are GAGs branched or unbranched?
They are unbranched
## Footnote
GAGs do not contain N-acetyl neuraminic acid
141
Where are most GAGs found in the body?
Most are present extracellularly, except for heparin
## Footnote
They play various roles in the extracellular matrix
142
What is one major structural role of GAGs?
They form structural components of connective tissue such as bone, elastin, and collagen
## Footnote
GAGs are essential for maintaining the integrity of connective tissues
143
How do GAGs act as lubricants in tissues?
They can hold large quantities of water
## Footnote
This property helps cushion other tissues
144
What happens to glycosaminoglycans when compressed?
Water is squeezed out, and they occupy a smaller volume
## Footnote
Upon release of compression, they return to their original hydrated volume due to repulsion of negative charges
145
What property of GAGs contributes to the resilience of synovial fluid?
Their ability to return to a hydrated state after compression
## Footnote
This property is crucial for joint lubrication
146
Fill in the blank: The amino sugar in GAGs may also be _______ at carbon 4 or 6.
sulfated
## Footnote
Sulfation affects the function and interaction of GAGs
147
True or False: Heparin is an example of a GAG that is primarily found intracellularly.
False
## Footnote
Heparin is an exception and is found extracellularly
148
List three types of GAGs.
* Chondroitin sulfate
* Keratan sulfate
* Dermatan sulfate
## Footnote
These are specific examples of glycosaminoglycans
149
What is the function of hyaluronate?
It acts as a lubricant and shock absorber in tissues
## Footnote
Hyaluronate is a crucial component in synovial fluid and cartilage
150
What is the primary structure of Hyaluronic acid?
Glucuronic acid and N-acetyl glucosamine
## Footnote
Hyaluronic acid does not contain sulfate.
151
Where is Hyaluronic acid primarily found?
* Cartilage
* Synovial fluid
* Connective tissue
* Vitreous humor of the eye
* Tendons
* Ligaments
* Bones
## Footnote
These locations highlight the diverse roles of Hyaluronic acid in the body.
152
What are the functions of Hyaluronic acid?
* Lubricant in joints
* Makes cartilage compressible
* Cell migration during wound repair
* Cell migration during morphogenesis
* Binds collagen and holds fibers in a strong network
* Corneal transparency
## Footnote
Hyaluronic acid plays crucial roles in joint health and tissue repair.
153
What is the structure of Chondroitin sulfate?
Glucuronic acid with 4- and 6-sulfate
## Footnote
Chondroitin sulfate is a key component of cartilage.
154
What is Keratan sulfate primarily composed of?
N-acetylgalactosamine with sulfate on either C4 or C6
## Footnote
Keratan sulfate is found in cornea and cartilage.
155
What is the primary function of Heparin?
Intracellular anticoagulant compound
## Footnote
Heparin is found in mast cells and plays a vital role in preventing blood clotting.
156
What are the main locations of Heparan sulfate?
* Cell membrane
* Basement membrane of the kidney
* Blood vessels
## Footnote
Heparan sulfate is involved in various cellular functions, including acting as receptors.
157
What is the unique function of Hyaluronic acid in weight bearing?
It provides compressibility of cartilage
## Footnote
This property is essential for shock absorption in joints.
158
True or False: Glucosamine is found with sulfate on C2 and C6 in cartilage.
True
## Footnote
Glucosamine plays a structural role in cartilage.
159
What is the role of Glycosaminoglycans in kidney function?
Determining the charge selectiveness of glomerular filtration
## Footnote
This function is crucial for maintaining proper kidney filtration and function.
160
In which parts of the body is Induronic acid found?
* Cornea
* Sclera
* Skin
* Blood vessels
## Footnote
Induronic acid contributes to the structural integrity of these tissues.
161
What are glycoproteins?
Proteins that contain oligosaccharide chains
## Footnote
Glycoproteins play essential roles in cell-cell recognition and signaling.
162
What are the components of glycoproteins?
CHO component and protein component
## Footnote
The carbohydrate (CHO) component varies in size and type of sugars.
163
What are proteoglycans?
Chains of glycosaminoglycans attached to a protein molecule
## Footnote
Proteoglycans are key components of the extracellular matrix.
164
What are glycosaminoglycans?
Long unbranched polysaccharides composed of repeating disaccharide units
## Footnote
They often contain uronic acid and are important for structural support.
165
What is the typical structure of glycosaminoglycans?
Linear and unbranched
## Footnote
This structure contributes to their ability to form gels and provide cushioning.
166
What types of sugars are found in glycoproteins?
Oligosaccharide units
## Footnote
These units can include various monosaccharides like pentoses and hexoses.
167
What is a characteristic feature of proteoglycans?
Contain sulfate groups
## Footnote
This feature affects their charge and interaction with water.
168
Fill in the blank: Glycoproteins are important for _____ and signaling.
cell-cell recognition
## Footnote
They are involved in immune responses and tissue formation.
169
True or False: Glycoproteins can serve as cell receptors.
True
## Footnote
Glycoproteins are critical for binding hormones and other signaling molecules.
170
What is the role of glycosaminoglycans in the extracellular matrix?
Provide support and cushioning
## Footnote
They are essential for the structural integrity of tissues like cartilage and tendons.
171
What types of glycosaminoglycans contain uronic acid?
Those with sulfate groups
## Footnote
Uronic acid contributes to the negative charge and gel-forming properties.
172
What are some examples of blood group antigens?
A, B, and AB
## Footnote
These antigens are glycoproteins found on the surface of red blood cells.
173
Fill in the blank: _______ are proteins that contain oligosaccharide chains.
Glycoproteins
## Footnote
They play a crucial role in various biological processes.
174
What is the protein core in proteoglycans?
The central protein to which glycosaminoglycans are attached
## Footnote
This core structure is essential for the function of proteoglycans.
175
What is the typical size range of glycosaminoglycans?
More than 50 units
## Footnote
They can vary significantly in size, affecting their biological functions.
