Question

The carbohydrates located in the extracellular matrix of animal cells function to add tensile strength and resiliency of connective tissue and for cell-cell communication. Which of the following represents molecules partially made from carbohydrates that are found in the extracellular matrix? Select one:

a. Chondroitin sulphate, collagen, keratan sulphate, heparin, and glycosphinolipids

b. Chondroitin sulphate, hyaluronan, keratan sulphate, heparin, and glycosphinolipids

c. Chondroitin sulphate, hyaluronan, integrin, heparin, and glycosphinolipids

d. Chondroitin sulphate, hyaluronan, keratan sulphate, fibronectin, and glycosphinolipids

e. Collagen, hyaluronan, integrin, heparin, and glycosphinolipids

Q2. Which of the following statements is incorrect?

Select one:

a. Starch and glycogen molecules possessing the same number of glucose subunits contain the same amount of energy.

b. Glycogen contains more energy than starch due to its highly branched nature. This is why animals make glycogen and not starch.

c. Energy can be obtained from glycogen more quickly due to the greater number of non-reducing ends it contains as compared to starch.

d. a and b are both incorrect.

e. b and c are both incorrect.

Q3.

The energy required for polysaccharide synthesis:

Select one:

a. Is supplied by the incoming monomer in the form of an ADP-sugar molecule.

b. Always uses ATP as an energy source.

c. Is partially driven in the direction of polysaccharide formation by the hydrolysis of pyrophosphate.

d. Is made possible by the actions of ADP-sugar pyrophosphorylase.

e. a, c, and d.

Answer 1

Please find the answers below:

Answer 1: Choice b (all the biomolecules, intracellular or extracellular, listed in choice b contain at least a part of carbohydrate chain as their structural entity)

Answer 2: Choice d (although glycogen is made up of repeating units of glucose, glycogen requires energy to break itself down into monomers which can be metabolized to impart energy. Hence, it can not give more energy as compared to glucose subunits of equal number. Further, the attainment of a branched structure provides glycogen a thermodynamic stability and the internal energy of molecule is low as compared to naive glucose molecules)

Answer 3: Choice e (both ATP and NADPH can be used for providing energy while polysaccharide synethesis.)