29 Questions
Which disaccharide is found in milk and consists of glucose and galactose?
Lactose
Which structural polysaccharide is insoluble and not digestible by mammals?
Cellulose
Which polysaccharide serves as the animal storage polysaccharide, primarily found in muscle and liver tissues?
Glycogen
Which type of glycosaminoglycan provides hydration and cushioning in tissues?
Hyaluronic acid
Which type of polysaccharide forms a gelling agent in the presence of calcium ions, commonly found in fruits?
Pectin
Which type of glycoprotein is ubiquitous in the cell membrane and many proteins, often containing sialic acids?
Collagen
What type of linkage does glycogen have between glucose molecules?
α-1→4 and α-1→6 linkages
Which disaccharide consists of glucose and fructose?
Sucrose
Which type of glycosaminoglycan is commonly found in cartilage and provides resistance to compression?
Chondroitin sulfate
Which type of linkage does cellulose have between glucose molecules?
β-1→4 linkages
What role does amylose play in food digestion?
It serves as a homopolymer of glucose with α-1→4 linkages.
Which type of sugar is D-glucose?
Aldose
What is the main difference between α and β configurations of a sugar?
Position of the -OH group on the anomeric carbon
Which type of sugar can be tested for in urine in poorly controlled diabetes mellitus?
Glucose
What is the main characteristic of a glycoside bond?
Formed between a monosaccharide and another compound
Which type of sugar contains steroids as the aglycone and includes digoxin and ouabain?
\text{Cardiac glycosides}
\text{Which type of sugar is an example of a hexosamine component of glycoproteins?}
\text{D-glucosamine}
\text{What is the classification for sugars composed of two monosaccharide residues linked by a glycoside bond?}
\text{Disaccharides}
\text{Which type of sugar has 3-7 carbon atoms and can be classified as aldoses or ketoses?}
\text{Monosaccharides}
\text{Which type of sugar is formed by the condensation products of 3 to 10 monosaccharides?}
\text{Oligosaccharides}
\text{Which type of sugar is formed by the condensation of more than 10 monosaccharide units?}
\text{Polysaccharides}
What is the empiric formula for many of the simpler carbohydrates?
(CH2O)n, n ≥3
Which sugar is the major metabolic fuel of mammals and a precursor for synthesis of all other carbohydrates in the body?
Glucose
What is the storage form of energy in the body?
Glycogen
Which carbohydrate is important for the synthesis of lactose in milk and in glycolipids?
Galactose
Which disease is associated with carbohydrate metabolism and characterized by the body's inability to utilize glucose effectively?
Diabetes mellitus
What is the entire complement of sugars produced by an organism, whether free or in more complex molecules?
Glycome
What is the most abundant organic molecule in nature and widely distributed in plants and animals?
Carbohydrates (saccharides)
What serves as cell membrane components that mediate some forms of intercellular communication?
Glycoproteins
Study Notes
- Carbohydrates are classified into Monosaccharides, Disaccharides, Oligosaccharides, and Polysaccharides.
- Monosaccharides: simple sugars that cannot be hydrolyzed into simpler sugars. They have 3-7 carbon atoms and can be classified as aldoses (aldehyde group) or ketoses (ketone group). D-glucose is the most abundant monosaccharide in nature.
- Disaccharides: formed by the condensation of two monosaccharide units through a glycosidic bond. Examples include lactose (glucose + galactose), maltose (glucose + glucose), and sucrose (glucose + fructose).
- Oligosaccharides: condensation products of 3 to 10 monosaccharides. Most are not digested by human enzymes.
- Polysaccharides: formed by the condensation of more than 10 monosaccharide units. They may be linear or branched polymers and include glycogen, starches, cellulose, and inulin.
- D- and L- isomerism: sugars with the same chemical formula but different structures, determined by the Fischer projection. D-sugars have the -OH on the bottom-most chiral center on the right-hand side, while L-sugars have it on the left-hand side.
- Optical isomerism: presence of asymmetric carbon atoms confers optical activity on the compound. When a beam of plane-polarized light is passed through a solution, it rotates either to the right (dextrorotatory) or to the left (levorotatory).
- Pyranose and furanose ring structures: the ring structures of monosaccharides are similar to the ring structures of pyran or furan.
- Alpha- and beta-anomers: in the α configuration, the -OH group on the anomeric carbon projects to the same side as the ring, while in the β configuration, it projects to the opposite side.
- Epimers: isomers that differ as a result of variations in configuration of the -OH and -H on carbon atoms 2, 3, and 4 of glucose. The most important epimers are mannose (epimerized at carbon 2) and galactose (epimerized at carbon 4).
- Aldose-ketose isomerism: aldoses are reducing compounds, and can be tested for in urine in poorly controlled diabetes mellitus. Reducing sugars include glucose, galactose, and mannose.
- Glycosides: formed by the condensation between the hydroxyl group of the anomeric carbon of a monosaccharide and a second compound. If the hemiacetal portion is glucose, the resulting compound is a glucoside.
- Cardiac glycosides: important glycosides in medicine due to their action on the heart. They contain steroids as the aglycone and include digoxin and ouabain.
- Deoxy sugars: sugars in which one hydroxyl group has been replaced by hydrogen. An example is deoxyribose in DNA.
- Amino sugars (hexosamines): components of glycoproteins, gangliosides, and glycosaminoglycans. Examples include D-glucosamine and D-galactosamine.
- Disaccharides: sugars composed of two monosaccharide residues linked by a glycoside bond. Examples include sucrose, lactose, and maltose.
Learn the basics of carbohydrates, the most abundant organic molecules in nature, with important structural and metabolic roles in plants and animals. Understand their significance in providing dietary calories, storing energy in the body, and serving as cell membrane components.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
