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:

Solution & Explanation

Answer: (D) Statement I is incorrect but Statement II is true. Solution: Statement I is wrong because it inverts the terminals — NCERT states the first amino acid (left end) is the N-terminal and the last amino acid (right end) is the C-terminal, whereas the statement labels the first amino acid as C-terminal. Statement II is correct — adult human haemoglobin consists of 4 subunits, two of α type and two of β type. Hence Statement I is incorrect but Statement II is true. NCERT Reference: Ch 9, p.112, line ~3 — "The first amino acid is also called as N-terminal amino acid. The last amino acid is called the C-terminal amino acid."