Question

Which one of the following statements about Histones is wrong

• A. Histones carry positive charge in the side chain
• B. Histones are organized to form a unit of 8 molecules
• C. The pH of histones is slightly acidic
• D. Histones are rich in amino acids - Lysine and Arginine

Answer 1

The Correct Option is C

To determine which statement about histones is incorrect, we need to examine each option:

1. Histones carry positive charge in the side chain: Histones are proteins that play a crucial role in packaging DNA into chromatin. They are known to carry a positive charge because they are rich in basic amino acids like lysine and arginine, which have positively charged side chains at physiological pH. This positive charge allows them to interact with the negatively charged phosphate backbone of DNA, facilitating their role in DNA packaging.
2. Histones are organized to form a unit of 8 molecules: This statement is correct. Histones organize into octamers, which serve as the core around which DNA is wound to form a nucleosome. Each histone octamer consists of two copies each of histone proteins H2A, H2B, H3, and H4, totaling eight molecules.
3. The pH of histones is slightly acidic: This is the incorrect statement. Histones are actually slightly basic, not acidic, due to their high content of the basic amino acids lysine and arginine. Their basic nature contributes to their positive charge.
4. Histones are rich in amino acids - Lysine and Arginine: This statement is correct. Lysine and arginine are indeed abundant in histones, contributing to their positive charge and their ability to bind with negatively charged DNA.

Based on the analysis above, the statement "The pH of histones is slightly acidic" is incorrect. Histones are actually basic due to their composition of basic amino acids.