Basic Biochemistry Welcome to your Basic Biochemistry test. 1. According to Henderson-hasselbalch equation, in buffers pKa value of the compound is constant pH value is independent of the pKa pH value is dependent upon the -log pKa pH value is nothing but the log pKa None 2. Partition coefficient is Ability of the amino acid to interact with the molecules of the support material in chromatographic techniques Relative solubility of the amino acids in the polar and non-polar solvents Ability of the amino acids to dissolve in the water Ability of the amino acids to dissolve in non polar solvents None 3. Aliphatic groups of the amino acids tend weakly donate the electrons True False None 4. Which of the following amino acid is most commonly involved in the disulphide bond formation? Cys Asp Ser Glu None 5. Amino acid, Has only carboxyl and NH3 functional groups Has only two ionising groups Amino acid side chain can have ionisable functional groups Has -OH as an ionisable group None 6. Which of the following is true about the peptide bond? It is formed only when the alpha carboxyl group reacts with alpha amino group It is formed when any carboxyl group of the amino acid reacts with any amino group of the amino acid One amino acid is part of only one peptide bond Terminal amino acid is a part of two peptide bonds None 7. What is pI value? It is a negative log of the pKa value It is a value of pH where amino acids have net zero charge pH at which all the groups in an amino acid are protonated pH at which the proteins have net positive charge at low pH None 8. The difference between the paper electrophoresis and paper chromatography is Electric potential is applied between the two ends of the paper in electrophoresis In paper electrophoresis total charge on the molecule is responsible for the separation In paper chromatography molecules separate on the basis of the partition coefficient All of the above. None 9. Charged form of amino acids, Is neutral at pH 7 and this form is called as zwitterion Only COOH is ionised at pH 7 and this form is called as zwitterion Only NH3+ group is ionised at pH7 and this form is called as zwitterion Both the groups are ionised at pH 7 and this form is called as zwitterion None 10. Amino acids are linked by Ether bond Phospho-diester bond Peptide bond Glycosidic bond None 11. Proteins are made of Glucose Amino acids Cholesterol Nucelosides None 12. Which of the following is true? pKa values of carboxyl groups in all amino acids are same pKa values of carboxyl groups in the same amino acid are same Neighbouring chemical groups in amino acids influence the pKa value of the group None of the above None 13. Primary structure of the protein is The sequence of the mRNA coding for the corresponding protein The 3-D structure attained by the protein in vitro The amino acid sequence of the polypeptide The sequence of the amino acids that form the active site or binding site of the proteins None 14. The biological properties of the proteins are conferred by Physical properties of the amino acids Chemical properties of the amino acids Surrounding molecules of the proteins Concentration of the proteins in the cytoplasm 1&2 None 15. Functionality of the proteins depends on Overall 3-d structure of the protein Chemical properties of the constituent amino acids Intronic sequences All of the above 1 & 2 None Please fill in the comment box below. Time's up
