Question

Histones are very acidic (+charge) that interact with the nergativity-charges DNA

A)True
B)False

Answer 1

Histones are actually basic proteins with a positive charge that bind to negatively charged DNA, forming nucleosomes. These structures are regulated by epigenetic modifications, which can alter DNA-histone interaction without changing the DNA sequence.

Step-by-step explanation:

The statement that histones are very acidic and carry a positive charge is false. Histones are, in fact, basic proteins containing many lysine and arginine amino acids. They have positively charged side chains that enable them to bind to the acidic, negatively charged phosphodiester backbone of the double helical DNA.

Histones plus DNA form nucleosomes, and this complex further compacts into higher order structures as non-histone proteins are added. Chromosomes represent the most condensed form of chromatin. The tightness with which DNA is wrapped around histones is regulated by epigenetic modifications such as methylation and acetylation, changing the charge of the histones and consequently altering the structure's accessibility to transcription machinery.

Answer 2

Histones are basic proteins with a positive charge, not acidic as suggested by the question. Their positive charge interacts with the negative charge on DNA to form nucleosomes, contributing to DNA packaging into chromosomes.

The correct option regarding the question about histones being very acidic is option B) False.

Step-by-step explanation:

The statement that histones are very acidic and carry a positive charge is false. Histones are actually basic proteins, rich in amino acids like lysine and arginine, which give them a positive charge.

This positive charge allows histones to effectively interact with the negatively-charged phosphodiester backbone of DNA, facilitating the packaging of DNA into a structure known as the nucleosome. Nucleosomes further coil into a 30 nm fiber, and higher-order chromatin structures eventually form chromosomes, the most condensed form of chromatin present during metaphase of cell division.

Histone proteins undergo various chemical modifications, such as acetylation, methylation, and phosphorylation, which influence their interaction with DNA, thereby regulating genetic activity such as transcription.