Question: 142 Given below are two statements:
Statement I: A protein is imagined as a line, the left end represented by first amino acid (C-terminal) and the right end represented by last amino acid (N-terminal)
Statement II: Adult human haemoglobin, consists of 4 subunits (two subunits of \alpha type and two subunits of \beta type.)
In the light of the above statements, choose the correct answer from the options given below:
(1) Statement I is true but Statement II is false.
(2) Statement I is false but Statement II is true.
(3) Both Statement I and Statement II are true.
(4) Both Statement I and Statement II are false.
Answer: Option (2)
Explanation:
Proteins are formed by amino acids linked through peptide bonds,
creating a polypeptide chain with two distinct ends.
The left end of a protein chain is represented by the N-terminal, which has a free amino group,
and the right end is represented by the C-terminal, which has a free carboxyl group.
Statement I is incorrect because it wrongly interchanges the N-terminal and C-terminal positions.
Adult human haemoglobin is a conjugated protein composed of four polypeptide subunits.
It consists of two \alpha subunits and two \beta subunits, forming a tetrameric structure.
Therefore, Statement II is correct.
Hence, the correct answer is that Statement I is false but Statement II is true.