Q.24 Which of the following is correct statement about ATP
A. It contains two phosphodiester bond
B. It has one phosphate ester bond
C. It contains ribose sugar
D. It contains adenosine as nucleoside
Choose the correct answer from the options given below:
1. (A) – (I), (B) – (II), (C) – (III), (D) – (IV)
2. (A) – (I), (B) – (III), (C) – (II), (D) – (IV)
3. (A) – (I), (B) – (II), (C) – (IV), (D) – (III)
4. (A) – (III), (B) – (IV), (C) – (I), (D) – (II)
ATP, or adenosine triphosphate, is a crucial energy molecule in cells, and understanding its structure is key for biology exams. The correct answer to this multiple-choice question is option 4, as it properly matches the true statements about ATP’s bonds and components.
Correct Answer
Option 4: (A) – (III), (B) – (IV), (C) – (I), (D) – (II)
This matching is correct because only statements C and D are true about ATP, while A and B are false. ATP contains ribose sugar (C) and adenosine as its nucleoside (D).
Option Analysis
Statement A: Two Phosphodiester Bonds
False. ATP has no phosphodiester bonds; these link nucleotides in DNA/RNA. Instead, it features two high-energy phosphoanhydride bonds between the three phosphates and one phosphate ester bond to ribose.
Statement B: One Phosphate Ester Bond
True. The first phosphate attaches to ribose’s 5′ carbon via a phosphate ester (phosphoester) bond, which is lower energy than the anhydride bonds.
Statement C: Ribose Sugar
True. ATP’s sugar is β-D-ribose, a five-carbon pentose (unlike deoxyribose in DNA).
Statement D: Adenosine as Nucleoside
True. Adenosine (adenine base + ribose) is the nucleoside; ATP adds three phosphates to make it a nucleotide.
ATP Structure Overview
ATP = adenine (base) + ribose (sugar) + triphosphate chain. The ester bond links ribose to the first phosphate; anhydride bonds connect the rest, storing releasable energy via hydrolysis.
