COMMON RNA VIRUSES

COMMON RNA VIRUSES - DNA. Next this single strand of DNA is...

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  COMMON RNA VIRUSES    4. Reoviridae--- these are found in the respiratory and enteric (digestive) tracts of humans.  They contain double-stranded RNA. Viral mRNA is produced in the cytoplasm, where it is used  to synthesize viral proteins, including an RNA-dependent RNA polymerase. Many  -  strands of  viral RNA are produced and join  +  strands to form more double-stranded RNA for new virions.      5. Retroviridae-----this group includes the virus that causes AIDS (HIV-1 and HIV-2) as well as  some viruses that cause cancer. These viruses form mRNA and RNA for new virions as follows:       a. They carry their own polymerase, an RNA-dependent RNA polymerase called reverse  transcriptase.        b. Reverse transcriptase uses the RNA of the virus to synthesize a complementary strand of 
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Unformatted text preview: DNA. Next this single strand of DNA is used to form a complementary strand, producing double-stranded DNA. The original virus RNA is broken down. c. The new DNA is integrated into a chromosome of the host cell. In this state, spliced into a chromosome, the viral DNA is called a provirus. The provirus may remain inactive for long periods of time. If the host cell divides, each daughter cell receives a copy of the provirus along with the normal genes. d. The provirus may be transcribed. e. Resulting mRNA causes production of new viruses, which may be released and invade surrounding cells. f. Another possibility is that the provirus can convert the host cell into a cancer cell....
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This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

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