Hello guys,

 

I have a very quick question. They say nucleic acids are very large molecules and they cover some large distance I can not remember. Are they saying the length of these molecules are long or the size(meaning they are big with width). I don't understand how they can fit in a cell if they are that big. I can understand how they can wind a lot inside a cell, but that only explains the length. It is those trivia like things where they say this can cover the size of a tennis court and such things. Just give me your opinion. Thanks

DNA is very long but very thin (around 2.6nm wide). The largest human chromosome is roughly 72 centimeters long if you completely unwound it, but kept it as a double helix (it's 220 million base pairs - each nucleotide is around 0.33nm long). We have 22 pairs of chromosomes.

 

In the cell, the genetic material is VERY tightly wound up in to the chromosome structures - which include bead-like proteins called histones.

DNA is very long but very thin (around 2.6nm wide). The largest human chromosome is roughly 72 centimeters long if you completely unwound it, but kept it as a double helix (it's 220 million base pairs - each nucleotide is around 0.33nm long). We have 22 pairs of chromosomes.

 

In the cell, the genetic material is VERY tightly wound up in to the chromosome structures - which include bead-like proteins called histones.

 

Thanks Greippi, that's what I was thinking but you confirmed it. I have one quick question. When the DNA is double stranded, does that mean it has 2 separate helixes joined, or one long helix interwined to make 2 helixes. What I mean if it is former if you are unwinding the DNA helix, you have to keep one dna strand under the other dna strand to find the length, if the 2 dna strands are separate. I hope you understand what I mean. Thanks

Double stranded as in 2 strands make up one helix.

 

Just like this:

 

See, two sets of sugar/phosphate backbones.

Normally when someone says that a molecule is large they refer to its molecular weight.