Biology · Chemistry

Carbohydrates and Biomolecules

1,073 Questions

Carbohydrates and biomolecules questions test your understanding of sugars, monosaccharides, and metabolic substrates. The topic covers food transportation in plants and the biochemical properties of sweeteners. Practicing these questions builds a strong foundation for exam preparation.

Disaccharides and monosaccharidesArtificial sweetenersGlycogen storagePlant food transportGlycoprotein hormones

Carbohydrates and Biomolecules Questions

Multiple choice

Which of the following compounds is not present in dietary fibre?

  1. Cellulose

  2. Hemicellulose

  3. Cholesterol

  4. Beta-glucans

  5. Pectin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cholesterol is needed to construct the important membranes which surround cells. The body is able to manufacture cholesterol but is unable to destroy this substance. Cholesterol is removed from the body combined with bile acids. This removal is increased by dietary fibre and diminished in the absence of dietary fibre.

Multiple choice

Which of the following is/are converted to simple carbohydrates during digestion?

  1. Molasses

  2. Honey

  3. Alcohol

  4. White rice

  5. Peas
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Complex carbohydrates are formed from three or more sugar molecules but the sugar molecules are strung together to form longer, more complex chains. Complex carbohydrates include fibre and starch. Foods rich in complex carbohydrates include vegetables, whole grains, peas and beans. They are loaded with fibre, vitamins, minerals and micronutrients. During digestion, these complex carbohydrates are cleaved into single 6 carbon molecular units. Then they are absorbed and transported to the cells in the blood. These sugar molecules are either metabolized immediately to provide energy for the cell or stored in liver and muscle cells as glycogen to be used for future energy needs.

Multiple choice

Which of the following statements are correct about cell wall? a. It is made of a complex carbohydrate called cellulose. b. It is found in both plant and animal cells. c. It is semi-permeable. d. It is hard and rigid.

  1. Only a and b

  2. Only a and c

  3. Only a and d

  4. All a, b, c and d

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both the statements are correct about cell wall. Cell wall is made of a complex carbohydrate called cellulose. It is hard and rigid.

Multiple choice

What are the polymers of ribitol or glycerol phosphates covalently linked to the peptidoglycan of gram positive organisms?

  1. Diaminopimelic acid

  2. Lipopolysaccharide

  3. Teichoic acids

  4. N-acetylmuramic acid

  5. Lipid A
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Teichoic acids are bacterial polysaccharides of glycerol phosphate or ribitol phosphate linked to muramic acid of peptidoglycan via phosphodiester bonds. Teichoic acids are found within the cell wall of gram positive bacteria, such as species in the genera Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium and Listeria ,and appear to extend to the surface of the peptidoglycan layer. Teichoic acids are not found in gram- negative bacteria.

Multiple choice

Which of these is one of the major carbohydrates other than cellulose and hemicellulose present in the primary growing plant cell wall?

  1. Lignin

  2. Chitin

  3. Silica

  4. Glycoproteins

  5. Pectin
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

In the primary (growing) plant cell wall, the major carbohydrates are cellulose, hemicellulose and pectin. The cellulose microfibrils are linked via hemicellulosic tethers to form the cellulose-hemicellulose network, which is embedded in the pectin matrix.

Multiple choice

Which polysaccharide is the major constituent of fungal cell wall?

  1. Lignin

  2. Cellulose

  3. Pectin

  4. Chitin

  5. Hemicellulose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fungi possess cell walls made of the glucosamine polymer chitin. It is a polymer of nitrogen-containing polysaccharide rendering a tough protective covering or structural support in certain organisms.

Multiple choice

Which of the following statement(s) is/are true? P. Rings with five and six atoms monosaccharides are called pyranose and furanose forms, respectively. Q. In polysaccharides, monosaccharide units are joined by peptide bond. R. Trehalose consists of two glucose units.

  1. P only

  2. Q only

  3. R only

  4. P and Q

  5. Q and R
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The aldehyde or ketone group of a straight-chain monosaccharide will react reversibly with a hydroxyl group on a different carbon atom to form a hemiacetal or hemiketal, forming a heterocyclic ring with an oxygen bridge between two carbon atoms. Rings with five and six atoms are called furanose and pyranose forms, respectively, and exist in equilibrium with the straight-chain form. In polysaccharides, monosaccharide units are joined by glycosidic bond. Trehalose is a disaccharide and consists of two glucose monomeric units. Hence, only statement R is true.