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RNA
Like DNA, the RNA molecule, is
built up by nucleotides linked together in a chain.
There are some differences though:
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While the DNA consists of
two complementary strands attached to one
another, forming a double helix. The RNA molecule
is single stranded, and folded in various
shapes. |
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The four bases in the DNA
nucleotides are adenine, guanine, thymidine and
cytosine. In RNA thymidine is replaced by
uracil. |
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The sugar in DNA is
deoxyribose. In RNA it is ribose. |
There are three major types of RNA: 1) mRNA,
messenger-RNA, which transfer the information about
the aminoacid sequence from the DNA to the protein
synthesis. 2) rRNA, ribosomal-RNA, which builds up
the ribosome together with proteins. 3) tRNA,
transfer-RNA, which transfer aminoacids to the
ribosome for protein synthesis.
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