Question

In the sequence 'pApCpGpTpA', the 'p' between 'A' and 'C' represents.

• A. Phosphoester bond
• B. Ether linkage
• C. Phospho diester linkage
• D. Peptide bond

Hint:

In a nucleic acid sequence, the direction is assumed to be 5' to 3'. The 'p' between letters denotes the 3'-5' phosphodiester bond that forms the structural backbone of DNA and RNA.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Polynucleotide sequences are represented using single-letter abbreviations for the bases, where the linkage between nucleotides is indicated by lowercase "p".

Step 2: Detailed Explanation:
1. In the sequence 'pApCpGpTpA', the letters A, C, G, T represent the nucleosides (Adenosine, Cytidine, Guanosine, Thymidine).
2. The lowercase 'p' represents a phosphate group.
3. When positioned between two nucleoside letters (e.g., 'p' between 'A' and 'C'), it denotes a phosphodiester linkage connecting the 3'-hydroxyl group of the first pentose sugar to the 5'-hydroxyl group of the next pentose sugar.
4. The 'p' at the very beginning of the sequence represents a free 5'-phosphate group.

Step 3: Final Answer:
The 'p' represents a phosphodiester linkage.