IGNOU BCHET-149 June 2025 Previous Year Question Paper

Q1.(a) Describe the role of Golgi bodies in the protein processing of a Eukaryotic cell.

(b) Match the following : 5

(i) Singer and

(1) Synthesis of Nicolson lipids Gi) Selective

(2) Basic protein barrier Gii) Histones

(3) Ribosomes

(iv) Protein

(4) Fluid Mosaic synthesis Model

(v) Smooth

(5) Cell endoplasmic membrane reticulum

Q2.Differentiate between Prokaryotic and Eukaryotic cells. Describe them using suitable diagrams.

Q3.(a) State whether the following statements are True or False : 5

(i) All aldose sugars are derived from glyceraldehydes. Gi) D-Ribose is an aldose.

(ii) D-Ribulose is an aldose.

(iv) Polysaccharides upon hydrolysis yield 2-6 monosaccharide units.

(v) A fresh solution of D-glucose has a specific rotation of +52.7°.

(b) Explain the terms anomer' and mutarotation with reference to carbohydrates.

Q4.(a) Explain the following : 5

(6) Maltose is a reducing sugar and sucrose is a non-reducing sugar.

(ii) Cellulose is insoluble in water.

(b) How are peptides formed ? Write the reaction involved taking an example. Also give the type of reaction in the formation of peptides.

Q5.(a) Explain the stereochemistry of amino acids. How is the configuration of amino acids assigned ? Which isomer of amino acids is found in proteins ? 5

(b) Draw a schematic representation of an enzyme and label it with the following :

(i) Coenzyme

(i) Apoenzyme

(iii) Active site

(iv) Holoenzyme.

Q6.Write short notes on the following : 5+5

(a) Induced fit theory of specificity

(b) Isoenzymes

Q7.(a) What is the structural classification of lipids ? Explain with suitable examples of each type. 5

(b) What is the Fluid Mosaic Model ? How does it explain the membrane permeability ?

Q8.(a) What are the physiological functions of gluconeogenesis ? Explain. 5

(b) Describe in brief the TCA cycle. Illustrate your answer.