Science Question for Lance
posted by sara .
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???????
You give me the below answer, but the question does not say that DNA is acidic. it says that histones have a net positive charge, which derives from their ________ residue. Do you think think that "acidic" is what needs to go to the blank.
"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."
I found the following site and quote.
"The proteins associated with DNA are collectively known as histones. They are relatively short polypeptides which are positively charged (basic) and thus are attracted to the negatively charged (acidic) DNA."
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