BIOL 1101 Lecture Notes - Lecture 50: Red Blood Cell, Dna Virus, Mimivirus
16 Jun 2016
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Compare: red blood cell = frisbee, the largest marble = marble. Range in diameter from about 300nm to 20nm. Viruses always have a core composed of either dna or rna, but not both. Only cytomegalovirus and a large dna virus called a mimivirus have both. Of course, all cells do have both of these nucleic acids. viruses are classified as follows--into dna viruses and rna viruses and the viral nucleic acid could be either single-stranded (ss) or double-stranded (ds). This leads to four large groups of viruses: ssdna dsdna ssrna dsrna. The most common arrangement is dsdna, and most rna viruses tend to be ssrna. Further distinctions are made based on whether a single rna strand is directly useable as mrna (ssrna +), or whether it is complementary to the mrna that must be made (ssrna -). Viruses only have a small amount of nucleic acid. This may only be enough to code for 3-4 proteins.
