When a DNA molecule is in water, each base pair grabs a pair of electrons from s

Question

When a DNA molecule is in water, each base pair grabs a pair of electrons from surrounding water molecules, releasing a pair of hydrogen ions. As a result, the DNA molecule has a net charge.

According to the Wikipedia article Chromosome, the number of base pairs in human chromosomes ranges from about 50 million to 250 million. (The short "Y chromosome" is NOT the smallest!) This looks like a very reliable article with lots of technical detail and references to leading journals. Let's take 100 million as an average number of base pairs.

To get a sense of the charge involved, imagine that you had two coiled up DNA molecules each with a charge of 2 extra electrons per base pair. Suppose you supported them in a vacuum one meter apart. Since the size of a coiled DNA molecule is very small compared to one meter, we can model it as a point charge. Calculate the electric force between the two DNA molecules.

Answer:

(Of course, this isolation of charged DNA is not reasonable to do, because in its natural environment, there would be lots of positively charged ions between pairs of DNA strands.)

Scientists have shown that, within the limits of measurement and statistical analysis, the magnitudes of the negative charge on the electron and the positive charge on the proton are equal. Suppose, however, that the magnitude of the charge on the proton was very slightly larger than that on the electron. On the web, find a reliable site (or two) that tells you the number of electrons and protons in a copper atom, as well as the mass of a copper atom (in grams or kilograms). Enter the values you find here:

number of electrons:

number of protons:

mass of a single copper atom:

From this data, compute the total number of protons and electrons in a penny of mass 3 g, and calculate the net charge there would be on a penny if the charge on the proton was larger than the charge on an electron by 1 part in a million. With what force would two copper pennies then repel each other if they were held one meter apart? Since the size of a penny is small compared to one meter, we can treat the pennies as point charges.

Answer:

Explanation / Answer

For the second part values of number of electrons, number of protons and mass of a single copper atom are missed.

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