Chemistry Determining the Length of DNA Molecules Biology Lab Question

AI Thread Summary
The discussion revolves around calculating the total length of DNA in a human individual, given that one nucleotide pair occupies 3.4 angstroms and a human has approximately 6.4 billion nucleotide pairs per cell across 100 trillion cells. The initial calculation yields a total length of about 21.76 x 10^23 angstroms. Participants suggest that expressing this length in more relatable units, such as meters or kilometers, would enhance understanding. The conversation emphasizes the importance of using suitable units to convey large distances effectively. Ultimately, the focus is on ensuring clarity in scientific communication.
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Homework Statement



The length of DNA helix occupied by one nucleotide pair is 3.4 A (angstrom). A human has 10^14 cells and each human cell has about 6.4 x 10^9 nucleotide pairs of DNA. What is the length of double helix that could be formed from this amount of DNA in a human individual?

Homework Equations


The Attempt at a Solution



I'm not sure if the below is correct, and that is why I'm asking here. The first sentence of the question was actually not part of this question, but it sounded like necessary information. I'm not sure if I was suppose to use this. Also, the lab was about finding the length of an unknown DNA molecule. This question doesn't have anything to do with the unknown, right? Thank you!

(3.4 A)(6.4 x 10^9)(10^14)= 21.76 x 10^23 A

About, 21.76 x 10^23 A of double helix can be formed from this amount of DNA in a human individual.
 
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moonstaff said:
(3.4 A)(6.4 x 10^9)(10^14)= 21.76 x 10^23 A

About, 21.76 x 10^23 A of double helix can be formed from this amount of DNA in a human individual.

Looks OK - simple multiplication. But it might convey more more sense if you expressed the result in more suitable units.
 
What exactly would be more suitable units? Thank you in advanced!
 
moonstaff said:
What exactly would be more suitable units? Thank you in advanced!

Something that would mean more to the average person!
 
Oh I see, thank you!
 
Note: suitable unit depends on the distance. It is much easier to "feel" the length if it is expressed as 100 meters than as 105 mm, but distance between cities is much better expressed in km - 100 km is easier to understand than 105 m. When it comes to really large distances they often make more sense when expressed in astronomical units or light years (at least you can "see" them on the correct scale).
 
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