B. Answer the questions with reference to
the following figure.
I.
J
Polypeptide
SH
Oxidation
S
SH
Reduction
S
Polypeptide
6.
i. Name the type of bond formed
between two polypeptides.
ii. Which amino acid is involved in the
formation of such bond?
iii. Amongst I, II, III and IV structural
level of protein, which level of
structure includes such bond?
Answers
Answer:
Polypeptide: A linear organic polymer consisting of a large number of amino-acid residues bounded together in a chain, formimg part of (or the whole of) a protien molecule.
Oxidation: Oxidation is the loss of electrons. Reduction is the gain of electrons. In terms of oxygen transfer, oxidation may be defined as the chemical process in which a substance gains oxygen or loses electrons and hydrogen. When one of the reactants is oxygen, then oxidation is the gain of oxygen.
Reduction: Reduction is a process where a substance gains one or more electrons. Loses an oxygen atom or electronegative atoms and gains a hydrogen atom or electropositive atoms. Loses an increase in its oxidation number.
6.
i.) Amino acids are joined together by a special type of covalent bond (peptide bond) to form linear strucrures called polypeptides. The polypeptides are then folded into specific structures to form the functional conformation of the protein.
ii.) Proteins are linear polymers formed by linking the A - carboxyl group of 1 amino acid to the A - amino group of another amino acid with a peptide bond (also called as amino bond). The formation of dipeptide from two amino acids is accompained by the loss of water molecule.
iii.) For this question you have to give I, II, III and IV.