Home > Uncategorized > Mid term Biochemistry Mid term Biochemistry Welcome to your Mid Term Biochemistry Name Roll Number Email Phone# 1. At neutral pH amino acids usually present in the form of Neutral molecules with no charge on it Neutral molecules with positive charge on it Neutral molecules with negative charge on it Neutral molecules with positive as well as negative charge on it Negatively charged molecule 2. the amino acids may be polar or non polar some amino acids contain OH group in their side chains one of these is tyrosine alanine Aspartate Glutamate 3. Amino acids are not only present in proteins but may also act as neurotransmitters such as Glycal alanine butyric acid Glutamate GABA 4. some of the amino acids are very common while some are rare amino acids, one of the rare amino acid is Proline Lysine Hydroxyproline Tyrosine Lysine 5. the hydrophobic amino acids tend to fold and tightly packed in 3D structure in aqueous environment, which pair of amino acids is hydrophobic in nature Tryptophan and phenylalanine Glycine and Proline Threonine and Aspartic acid Methionine and Hitidine 6. Separation and purification methods of proteins depends upon which of these physical properties Size Charge Solubility Size and charge size and solubility 7. Proteins vary greatly in mass but not in ------- Charge Size Solubility Density 8. Protein are purified on the bases of difference in their masses Differential centrifugation Fractionation Rate zonal centrifugation Ultracentrifugation 9. If protein has a net positive charge at pH7 it will usually binds to a column of beads containing amino groups carboxylate groups Na ions ion exchange 10. Salting out is a technique to purify proteins, it is also useful for centrifugation concentrating the proteins separation of soluble proteins from non-soluble proteins all are true 11. ----- is responsible for specifying the 3D shape of a protein? Interaction with other polypeptides Interaction with molecular chaperons The amino acid sequence The peptide bond 12. Which one is true about proteins? Proteins are made up of amino acids. Protein is the only nutrient that can build, repair and maintain body tissues. Proteins are essential for the development of skin, teeth and bones. All of the above 13. Which of the following statements is true about the (primary ) structure of proteins The helical structure of the protein Subunit structure of the protein Three-dimensional structure of the protein The sequence of amino acids joined by a peptide bond 14. Some polypeptide chains fold into two or more compact regions, these compact regions are called Dimers Motif Domain Ribbon 15. Trehalose is disachharide that is made up of two glucose units with ----glycosidic bond alpha 1-2 glycosidic bond alpha 1-1 glycosidic bond alpha 1-4 glycosidic bond alpha 1-6 glycosidic bond 16. difference between cellulose and chitin is Replacement of the hydroxyl group at C3 with an acetylated amino group Replacement of the hydroxyl group at C2 with an acetylated amino group Replacement of the hydroxyl group at C5 with an acetylated amino group Replacement of the hydroxyl group at C4 with an acetylated amino group 17. Each cellulose molecule in cell wall of plants is composed of 100 to 200 glucose molecules 1000 to 2000 glucose molecules 2000 to 4000 glucose molecules 3000 to 6000 glucose molecules 18. Sucrose is a disaccharide that is made up of alpha 1-4 glucosidic bond between glucose and fructose alpha 1-2 glucosidic bond between glucose and fructose beta 1-4 glucosidic bond between glucose and fructose beta 1-2 glucosidic bond between glucose and fructose 19. Any change in the relative positions of the groups attached to any of the chiral carbon atoms in a Fischer projection produces either a different enantiomer or a diastereomer optical rotation sterioisomers polarizability 20. is usually produced as intermediate product in pentose phosphate pathway and calvin cycle Glucose Erythose Fructose lactose Time is Up!