Question

What are retroviruses? How do they reproduce and what is the role of the enzyme reverse transcriptase?

Answer 1

Retroviruses are single stranded RNA viruses. HIV is the example of retrovrus. Once retroviruses enter to the host cell, it converts its RNA into DNA with the help of enzyme reverse transciptase. At this point viral DNA is known as provirus. Then viral DNA is integrated with host genome with the help of enzyme integrase. Once viral DNA is integrated with host genome the host cell treats the viral DNA as part of its own genome, translating and transcribing the viral genes along with the cell's own genes and thus during transcription the viral DNA also transcribes and produces RNA. Some portion of the transcribed RNA act as genome for the new virus while some portion of transcribed RNA synthesize proteins required to assemble new copies of the virus.