Carbohydrates MCQ

• Common carbohydrates found in nature are ________.

  A) aldehydes with two or more hydroxyl groups and ketones with two or more hydroxyl groups.

  B) aldehydes with two or more hydroxyl groups.

  C) amines with two or more hydroxyl groups.

  D) ketones with two or more hydroxyl groups.

  E) All of the answers are correct.

  A
• Glycoproteins are normally...

  A) found inside organelles.

  B) found on the inner face of the plasma membrane.

  C) found on the outer face of the plasma membrane.

  D) either secreted or can be found on the outer face of the plasma membrane.

  E) secreted as extracellular proteins.

  D
• In glycoproteins, the carbohydrate moiety is always attached through the amino acid residues:

  A) aspartate or glutamate.

  B) glutamine or arginine.

  C) asparagine, serine, or threonine.

  D) glycine, alanine, or aspartate.

  E) tryptophan, aspartate, or cysteine.

  C
• Starch and glycogen are both polymers of:

  A) α-D-glucose.

  B) β-D-glucose.

  C) fructose.

  D) glucose1-phosphate.

  E) sucrose.

  A
• The basic structure of a proteoglycan consists of a core protein and a:

  A) glycolipid.

  B) glycosaminoglycan.

  C) lipopolysaccharide.

  D) peptidoglycan.

  B
• What chemical feature determines if a sugar is an aldose or a ketose?

  A) If the enantiomers resemble either glyceraldehyde or dihydroxyacetone

  B) If the epimers differ in configuration around one carbon or more than one carbon

  C) The number of chiral carbons

  D) The position of the carbonyl carbon

  D
• When two carbohydrates are epimers:

  A) one is a pyranose, the other a furanose.

  B) one is an aldose, the other a ketose.

  C) they are mirror images of each other.

  D) they differ only in the configuration around one carbon atom.

  E) they differ in length by one carbon.

  D
• Which group of carbohydrates is unique in that its members are strong anions, containing a significant concentration of carboxylate and sulphate?

  A) Amylopectin

  B) Glycosaminoglycans

  C) Glycogen

  D) Peptidoglycans

  E) Proteoglycans

  B
• Which of following is an anomeric pair?

  A) α-D-glucose and β-D-glucose

  B) α-D-glucose and β-L-glucose

  C) D-glucose and D-fructose

  D) D-glucose and L-fructose

  E) D-glucose and L-glucose

  A
• Which of the following explains how some viruses gain entry into specific cells?

  A) by attaching to ion channels.

  B) by binding to glycoproteins on the cell surface that are unique to specific cells.

  C) by cleaving the glycosidic bonds of cell surface glycoproteins and altering protein shapes.

  D) All of the answers are correct.

  E) None of the answers is correct.

  B
• Which of the following is the storage form of glucose in animals?

  A) Amylopectin

  B) Amylose

  C) Cellulose

  D) Glycogen

  E) Chitin

  D
• Which of the following statements about starch and glycogen is false?

  A) Amylose is unbranched; amylopectin and glycogen contain many (α1→6) branches.

  B) Both are homopolymers of glucose.

  C) Both serve primarily as structural elements in cell walls.

  D) Both starch and glycogen are stored intracellularly as insoluble granules.

  E) Glycogen is more extensively branched than starch.

  C
• Which of the following terms describes a class of compounds with the molecular formula Cn(H2O)n?

  A) Glycogen

  B) Monosaccharides

  C) Mucoproteins

  D) Polysaccharides

  E) Proteoglycans

  B
• What term describes stereoisomers that are mirror images of each other?

  A) Anomers

  B) Epimers

  C) Enantiomers

  D) Diastereomers

  C
• At what location(s) within a cell is/are proteins glycosylated?

  A) ribosome

  B) endoplasmic reticulum

  C) cytoplasm

  D) golgi complex

  E) endoplasmic reticulum and golgi complex

  E