英語の生物の和訳です。
1.4 DNA structure and function
DNA is huge ladder-like molecule made up of sugar , phosphate and four organic bases called Adenine, Guanine, Cytosine and Thymine.The bases will only join up in the pairs A to T and G to C.
The two halves of the ladder can also un-zip between the pairs of bases.They do this:
(a) At mitosis: each half ladder forms the other half on itself.So two ladders,which are identical, result.This is the reason why a chromosome that splits in mitosis forms two identical chromosomes.
(b) When genes make proteins: each half ladder forms a related substance, RNA(very similar to DNA) on it.This then detaches, passing to the ribosomes.RNA carries the sequence of bases that were in the DNA.Each three letter ‘word’(triplet),e.g.AGC attracts particular amino acid to the ribosome.
The sequence of the hundreds of triplets is what determines the kind of protein formed at the ribosomes-each protein has its own unique DNA sequence.
Thus a length of DNA with its own unique sequence is a gene; and a gene is what is used to make its own, unique,protein by linking a particular sequence of amino acids together at ribosome.
The‘ladder’structure of DNA is in fact turned into a spiral(double helix) thread,with 10 base pairs per complete 360°turn.This has little to do with the function of DNA but it was a crucial fact, discovered by Franklin, Wilkins, Watson and Crick, in determining its structure.
かなり長いですがお願いします。
すごく急いでます。