Practical - revision MCQ questions for carbohydrate lectures PDF

Preview

Summary

Revision MCQ questions for carbohydrate lectures...

Description

Revision questions for the carbohydrate lectures Introduction

1 c. 10 to 20 d. more than 5

You may be wondering why there are so many questions. The MCQ questions are designed to cover what you need to know about the lectures and they complement the summaries at the end of each lecture. Consider the MCQ questions as a revision tool. The questions cover most of the material that you need to know and also give you an idea of the types of questions you will be asked. Exam questions are derived from questions you are asked (although they will not be exactly the same). If you can answer questions then that means you know the material and there is unlikely to be any unpleasant surprises in the final exam.

5. The monosaccharide shown can be referred to as a: a. tetrose b. triose c. pentose d. hexose

Dr. P. Arthur

LECTURE 1 Revision 1. Which of the following is most likely to be a carbohydrate: A. C4H8O4 B. C3H3O3 C. C5H10O2 D. C6H6O6

6. The monosaccharide shown can be referred to as a: a. ketohexose b. aldohexose c. pentose d. triose

Fructose

2. The chemical formula for glucose C6H12O6. What is the chemical formula for the fructose? A. C6H12O4 B. C6H6O5 C. C6H6O6 D. C6H12O6 3. Which of the following is true of the hydrolysis of carbohydrates? a. carbohydrates cannot be hydrolyzed b. hydrolysis of carbohydrates can only yield polyhydroxyaldehydes c. hydrolysis of carbohydrates can only yield polyhydroxyketones d. hydrolysis of carbohydrates can yield polyhydroxyaldehydes and/or polyhydroxyketones 4. How many monosaccharide units are in molecules called oligosaccharides? a. 3 to 6 b. 2 to 10

7. The functional group shown can be referred to as a: a. ether b. acetyl c. ester d. carbonyl

8. The functional group shown can be referred to as a: a. ether b. acetyl c. ester d. carbonyl

Revision questions for the carbohydrate lectures

2

9. The functional group shown can be referred to as a: a. ether b. aldehyde c. carboxylate d. ketone

10. The functional group shown can be referred to as a: a. amino b. aldehyde c. amido d. ketone 11. Carbohydrates that are optically active have the ability to rotate plane-polarized light. Light rotated in a clockwise direction is represented by the symbol a. L b. R c. (+) d. α 12. Which of the following refers to the common biological form of glucose a. D-glucose b. R-glucose c. L-glucose d. S-glucose

13. How many stereogenic centres does the compound shown above contain: a. 6 b. 5 c. 4 d. 3

14. The pair of carbohydrates shown would be considered to be a. diastereomers b. enantiomers c. non-chiral d. anomeric

15. The structure shown would be considered to be a. the α form of a furanose b. the  form of a furanose c. the α form of a pyranose d. the  form of a pyranose

16. Which is most correct for the structure shown a. the hydroxyl groups are equatorial in the boat conformation b. the hydroxyl groups are axial in the boat conformation c. the hydroxyl groups are equatorial in the chair conformation d. the hydroxyl groups are axial in the chair conformation 17. The cyclic structures of monosaccharides are which of the following? a. acetals b. hemiacetals c. ethers d. esters 18. When an aldohexose such as glucose adopts the pyranose structure which atoms are connected by an oxygen atom? a. C-1 and C-5 b. C-1 and C-6 c. C-2 and C-5 d. C-2 and C-6

Revision questions for the carbohydrate lectures

19. When glucose adopts a pyranose structure which carbon is the anomeric carbon? a. C-1 b. C-2 c. C-5 d. C-6

3

6. To which carbon of a monosaccharide is the amino group bound in the amino sugars commonly found in nature? a. C-1 b. C-2 c. C-5 d. C-6

LECTURE 2 Revision

1. Choose the most correct answer. The structure shown is an example of a: a. amino monosaccharide b. sugar alcohol c. monosaccharide d. deoxy sugar 2. The reaction of monosaccharides to form a disaccharide is an example of which of the following reactions? a. condensation b. hydrolysis c. reduction d. oxidation

3. Choose the most correct answer. The bonds in the polysaccharide can be described as: a. (14) glycosidic bonds b. (16) glycosidic bond c. (16) glycosidic bond d. (14) glycosidic bond 4. Which of the following contains (1  4) glycosidic bonds? a. amylopectin b. amylose c. glycogen d. none of these 5. Choose the most correct answer. a. A homopolysaccharide consists of several different monosaccharides b. A heteropolysaccharide is a polymer of the same monosaccharides c. Cellulose is an example of a homopolysaccharide d. Amylose is an example of a heteropolysaccharide

7. Choose the most correct answer. The bond in the disaccharide is a: a. (14) glycosidic bond b. (16) glycosidic bond c. (16) glycosidic bond d. (14) glycosidic bond

8. Choose the most correct answer. The structure shown is an example of a: a. amino monosaccharide b. sugar alcohol c. monosaccharide d. deoxy sugar LECTURE 3 Revision 1. Which of the following is true of amylose? a. it consists of as many as 4000 D-glucose units linearly linked by α(1  4) glycosidic bonds b. it consists of as many as 4000 D-glucose units linearly linked by (1  4) glycosidic bonds c. it consists of as many as 10,000 D-glucose units linearly linked by α(1  4) glycosidic bonds and there are branches every 24-30 units via α(1  6) glycosidic bonds d. it consists of as many as 10,000 D-glucose units linearly linked by (1  4) glycosidic bonds and there are branches every 24-30 units via (1  6) glycosidic bonds

2. Which of the following is correct for the cell wall of Gram positive bacteria a. Composed of 2 lipid bilayers and the covered with an outer peptidoglycan shell b. Composed of 1 lipid bilayers with an outer peptidoglycan coat c. Composed of a peptidoglycan layer with an outer lipid bilayer

Revision questions for the carbohydrate lectures d. Composed of 2 lipid bilayers with a peptidoglycan shell in between 3. Which of the following is correct for the cell wall of Gram negative bacteria a. Composed of 2 lipid bilayers and the covered with an outer peptidoglycan shell b. Composed of 1 lipid bilayers with an outer peptidoglycan coat c. Composed of a peptidoglycan layer with an outer lipid bilayer d. Composed of 2 lipid bilayers with a peptidoglycan shell in between 4. Which of the following is a correct statement about carbohydrates on the surface of animal cells a. There is peptidoglycan polymer which covers the cell to give strength and rigidity. b. Composed of 1 lipid bilayer with an outer peptidoglycan coat c. The term glcyocalyx describes the carbohydrates found on surface of cells d. Composed of a peptidoglycan layer with an outer lipid bilayer 5. Which of the following is a correct statement about N-linked oligosaccharides a. N-linked saccharides are attached via the amide nitrogens of asparagine residues. b. N-linked saccharides are attached via the hydroxyl groups of serine. b. N-linked saccharides are attached via the hydroxyl groups of threonine. b. N-linked saccharides are attached via the hydroxyl groups of glutamate. 6. Which of the following is an incorrect statement about O-linked oligosaccharides a. O-linked saccharides are attached via the amide nitrogens of asparagine residues. b. O-linked saccharides are attached via the hydroxyl groups of serine. b. O-linked saccharides are attached via the hydroxyl groups of threonine. b. N-acetylglucosamine is a carbohydrate commonly linked to the protein side chains

7. Part of a glycoprotein is shown. Which of the following is a correct statement. a. The carbohydrate is likely linked to a serine residue.

4 b. The linkages between the carbohydrate residue and the protein backbone can be described as a (β1→3) glycosidic bond. a. The carbohydrate is likely linked to a threonine residue. d. The glycoprotein is N-linked to the protein backbone.

8. Part of a glycoprotein is shown. Which of the following is a correct statement. a. The carbohydrate is linked to the protein backbone is likely to be glucose linked to an asparagine residue. b. The carbohydrate is linked to the protein backbone is likely to be galactose linked to a threonine residue. c. The carbohydrate is linked to the protein backbone is likely to be N-acetylgalactosamine linked to a serine residue. d. The carbohydrate is linked to the protein backbone can be described as a peptidoglycan.

9. Part of a glycoprotein is shown. Which of the following is the most correct statement. a. The carbohydrate linkage to the protein backbone is likely to be glucose linked to an asparagine residue. b. The carbohydrate linkage to the protein backbone is likely to be galactose linked to a serine residue. c. The carbohydrate linkage to the protein backbone is likely to be N-acetylglucosamine linked to an asparagine residue. d. The carbohydrate linkage to the protein backbone is likely to be an O- linkage to a serine residue.

Revision questions for the carbohydrate lectures LECTURE 4 Revision 1. Which of the following is not a correct statement about proteoglycans a. They can be heavily glycosylated b. They can be soluble c. They can be transmembrane proteins d. They are homopolysaccharides

2. Which of the following is correct for the polysaccharide shown a. It likely to be a glycosaminoglycan b. It is heteropolysaccharide containing N-acetyl groups c. It is a homopolysaccharide d. It is a proteoglycan 3. Which of the following is not a correct statement about glycosaminoglycans. a. Glycosaminoglycans are generally N-linked to the protein backbone b. At least one residue in the repeating disaccharide carries a negative charge. c. Glycosaminoglycans are hydrophilic d. They are linear chains of repeating disaccharides. 4. Which of the following is the most correct statement about glycosaminoglycans. a. Glycosaminoglycans are linked via a oligosaccharide N-link to the protein backbone through a serine residue b. Glycosaminoglycans are linked via a oligosaccharide O-link to the protein backbone through a asparagine residue c. Glycosaminoglycans are linked via a oligosaccharide O-link to the protein backbone through a serine residue d. Glycosaminoglycans are linked via a oligosaccharide N-link to the protein backbone through a asparagine residue 5. Which of the following is not a correct statement about glycosaminoglycans a. They are linear chains of repeating disaccharides b. They can considered to be oligosaccharides c. They are highly negatively charged d. They are components of proteoglycans 6. What is the most correct statement about cartilage on the endcaps of bones such as the femur.

5 a. It contains proteoglycans which are responsible for the tensile strength of cartilage b. It contains collagen which gives cartilage tensile strength c. The hydrophobic properties of proteoglycans cause water to be drawn into the tissue d. Cartilage is homopolysaccharides such as glycogen LECTURE 5 Revision 1. Glycogen is structurally similar to which of the following? a. amylopectin b. amylose c. cellulose d. none of these 2. Which of the following is the most correct statement about glucose. a. Glucose is stored as the homopolysaccharide glycogen in the liver b. Glucose is stored as the polysaccharide amylopectin in the liver c. Glucose is stored in the liver in the form of glycosaminoglycans d. Glucose is stored as the polysaccharide amylose in the liver 3. Which of the following is the most correct statement. a. The synthesis of glycogen from glucose requires energy in the form of ATP and UTP. b. The enzyme UDP-glucose pyrophosphorylase catalyses the formation of glucose 1-phosphate from glycogen. c. The enzyme glycogen phosphorylase catalyses the formation of glycogen from glucose 1phosphate. d. Glycogen synthesis from glucose is an example of a catabolic pathway. 4. Which of the following is the most correct statement about carbohydrate storage in the liver. a. Glucose is stored as a proteoglycan, a homopolysaccharide. b. Glucose is stored as glycogen, a homopolysaccharide. c. Glucose is stored as lactose, a disaccharide d. Glucose is stored as sucrose, a homopolysaccharide

Revision questions for the carbohydrate lectures

5. Which of the following is the most correct statement. a. Glucose can be used by cells to generate energy in the form of ATP. b. An example of catabolic process would be the conversion of glucose to glycogen. c. The enzyme phosphoglucomutase catalyses the formation of glycogen from glucose 1-phosphate. d. The enzyme glycogen synthase catalyses the the attachment of glucose 6-phosphate to glycogen. 6. Which of the following is the most correct statement. a. Hexokinase is an enzyme which catalyses the synthesis of glycogen from UDP-glucose. b. Glucose 6-phosphatase catalyses the conversion of glucose to glucose 6-phosphate. c. The enzyme glycogen synthase catalyses the the attachment of UDP -glucose to glycogen. d. Hexokinase catalyses the conversion of glucose 6-phosphate to glucose. 7. Which of the following is the most correct statement about glycogen storage in the liver. a. The enzyme glycogen synthase catalyses the release of glucose 1-phosphate from glycogen. b. Catabolic reactions cause glycogen in the liver to release glucose into the blood stream. c. Catabolic reactions result in glucose being converted to glycogen. d. Glycogen is a homopolysaccharide composed of glucose residues with 1,4 and 1,6 glycosidic bonds

6

Revision questions for the carbohydrate lectures

7

The practise short answer questions are example questions only. You are expected to know about other carbohydrates as well (consult the lecture notes). PRACTISE SHORT ANSWER QUESTIONS QUESTION 1

For the carbohydrate shown, answer the following questions: 1. What functional group does A point to? 2. What functional group does B point to? 3. What is the linkage that C points to? 4. What functional group does D point to? 5. What is the name given to this type of carbohydrate? 6. What are three key features of this type of carbohydrate? 7. What is the name used to describe the protein that the carbohydrate is part of?

QUESTION 2

1. What functional group does A point to? 2. What is the linkage that B points to? 3. What functional group does C point to? 4. What is the name used to describe the protein that the carbohydrate is part of? 5. How would the carbohydrate attachment to the protein be classified 6. What are the possible amino acid residues that could link to the carbohydrate? 7. What descriptor could be used for the 6 member ring structure for the carbohydrates?

Revision questions for the carbohydrate lectures

Lecture 1 1. A 2. D 3. D 4. B 5. D 6. B 7. B 8. D 9. C 10. A 11. C 12. A 13. D 14. A 15. B 16. D 17. B 18. C 19. B Lecture 2 1. A 2. A 3. A 4. D 5. C 6. B 7. A 8. D Lecture 3 1. A 2. B 3. D 4. C 5. A 6. A 7. B 8. C 9. C Lecture 4 1. D 2. C 3. A 4. C 5. B 6. B Lecture 5 1. A 2. A 3. A 4. B 5. A 6. C 7. B

8...