Chemical Bonding and Elements in Biological System (DSC-4, Chemistry-02) — DU B. Sc. Life Science (Chemistry) Previous Year Question Papers

(b) Ner, has a dione mo sept, while BF, has (c) Inability to synthesize transferring may result in anemia as well as overload of iron. 6. (a) Explain the role of magnesium in chlorophyll & in energy production? 5 (b) Arrange and explain the following molecules in the increasing order of their solubility in water. (c) Explain the role of calcium in the process. of blood clotting. Bonding and Elements in Biological Systems 1. (a) Calculate the heat of formation of CsF from its elements from the following data usin Born-Haber cycle. Electron gain enthalpy of F = -328 kJmol-1 Ionization energy of Cs = +357.7 kJmo1-1 Heat of Sublimation of Cs = +76.1 kJmo1-1 Bond dissociation energy of F2 = +158 kJmoll Lattice energy of CsF (s) = -740 kJmol-1 (b) Draw the Molecular orbital energy level diagram of NO molecule and also calculate the bond order of,NO, N02+. 5 (c) ` What is>meant by active 'transport in Na/K pump? Give the diagrarrimatic representation of the process and explain the mechanism involved in it. 5 > 2. (a) The dipole moment of LiF` is 6.32 D and the bond distance is 156 pin. What will be the % of ioliic characte,t` in LiF`? (ID=3..33.6xlo-30 C.in, ch€irge on one electron=1.6x to-19C) `` 5 (b) Write down the main p.ostulates and Limitations of valence Bond Theory. 5 (c) Explain essential and non-essential elements in the bio-system with examples? Draw the Dose-response curve for essential elemerits in a human body. 5 3. (a) Write a short note on: (i) Application of Fajan's rule (ii.) Born-Lande equation and explain the meaning of various terms` involved it. (b) Compare the HNH bond angle in NH3 and FNF bond angle in NF3. Which bond angle is higher and why? 5 (c) .Where and in what form iron is stored in human body? How is it taken from the storage sites to the sites .for incorporation into hemoglobin? 5 4. (a) Explain inter arid intramolecular hydrogen bonding with suitable examples. How it affects the melting/boiling point of compounds. 5 (b) Draw the Lewis structure of ando Also find out the hybridization and molecular geometry. 5 (c) Discuss the toxic effects of Cadmium (Cd) and explain the reasons for its toxicity. What are the available methods for its treatment? 5 5. (a) Draw the Molecular orbital energy level diagram of 02 molecule and arrange the following in increasing ol.der of their bond length„ „ , 02. 5