Histones interact with DNA at specific loci because DNA has phosphate functional groups. This interaction occurs because histones have a net _____ positive charge, which derives from their ______ residues, and interact with DNA because of its net _______ charge.

a. negative, basic, positive
b. negative, baseic, negative
c. negative, acidic, positive
d. positive, basic, negative
e. positive, acidic, negative

I know for sure that it is either "d" or "e" becaues histones have a net positive charge and DNA has a net negative charge. So, it all comes down to whether it's acidic or basic. I believe it is "e". (when they interact, do they end up with positive net charge? negative net charge? or neutral? if positive that should be basic and if negative, that should be acidic???????

If DNA is an acid how can it have a negative charge? An acid is electon hungry. As an example take HCL
when it ionizes in water it becomes an acid where the H+ ions make it acidic. H+ is an ion that has a positive charge.

But the question doesn't say that DNA is acidic, it says that histones have a net positive charge, which derives from thier _______ residues. In this case "acidic" should be the word to fill the blank not basic. am I right?

Explain Bot Explain Bot answered
9 months ago

You are correct in assuming that the correct answer is either option "d" or "e" since histones have a net positive charge and DNA has a net negative charge. To determine which option is correct, we need to consider the charges of the respective molecules.

Histones are proteins comprised of amino acid residues. Amino acids can have different properties, including being either acidic or basic. The net positive charge on histones is derived from their basic residues. Therefore, we can eliminate option "e" since it suggests that the positive charge on histones is derived from their acidic residues.

Now, let's consider DNA. DNA is made up of nucleotide monomers, which consist of a deoxyribose sugar, a phosphate group, and a nitrogenous base. The phosphate group in DNA has a negative charge due to the presence of phosphate functional groups, particularly the negatively charged phosphate ions (PO4^3-). This results in DNA having an overall net negative charge.

Based on this information, we can see that histones, with their net positive charge derived from basic residues, interact with DNA because of its net negative charge. Therefore, the correct answer is option "d" - positive, basic, negative.