NEET Practice Questions (MCQs) with Answers & Solutions

(a) Starch and glycogen are storage polysaccharide and cellulose is a structural polysaccharide. Starch has straight chain of 1,4 $\mathrm{\alpha }$-D pyranose glucose units and side chains or amylopectin part of 2-200 thousand glucose units that are attached to straight chains by 1,6 $\mathrm{\alpha }$-D glycosidic bonds.

Glycogen is a long chain branched polymer of 5-300 thousand glucose units, straight chain linked by $\mathrm{\alpha }$-D 1-4 glycosidic bonds and side chains through $\mathrm{\alpha }$-D 1$\to$6 glycosidic bonds.  

Cellulose, a fibrous polysaccharide has a linear chain of 6-10 thousand 1$\to$4 linked $\mathrm{\beta }$-pyranose glucose chain.

Km is the concentration of substrate which permits the enzyme to achieve half Vmax. An enzyme with a high Km has a low affinity for its substrate, and requires a greater concentration of substrate to achieve Vmax.

(b) Cellulose is fibrous polysaccharide that forms the structural component of plant cell wall, some primitive fungi and tunic of ascidians. Cellulose is the most abundant organic substance on earth. It can be digested by only a few microbes present in the gut of ruminants and white ants.

Answer 3. Read page 144, XI NCERT

Answer 2. Read page 144, XI NCERT

Answer 3. Reas page 150, XI NCERT

Answer 3. Read page 156, XI NCERT

Answer 2. Read page 158, XI NCERT

Answer 1. Read page 159, XI NCERT

Answer 2. Factual question