Basic Biochemistry Welcome to your Basic Biochemistry test. 1. 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 2. Proteins are formed of one or mode polypeptides. True False None 3. 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 4. Which of the following amino acid does not have ionisable side chain? Asp Glu Tyr Lys None 5. Which of the following amino acid is most commonly involved in the disulphide bond formation? Cys Asp Ser Glu None 6. 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 7. Amino acids are linked by Ether bond Phospho-diester bond Peptide bond Glycosidic bond None 8. 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 9. Henderson-hasselbalch equation helps determining pH By using the ratio of the absolute concentrations of the deprotonated to protonated forms of the compound By using log value of the ratio of the absolute concentrations of the deprotonated to protonated forms of the compound By using log of pKa None of the above None 10. Proteins are made of Glucose Amino acids Cholesterol Nucelosides None 11. Number of common amino acids in biological system is 20 27 30 11 None 12. 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 13. 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 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. 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 Please fill in the comment box below. Time's up
