Question

A specific virus contains RNA as its genetic material. a. Why would reverse transcription be used in the life cycle of this type of virus? b. What is the name of this type of virus?

Short answer

a. Reverse transcription allows RNA viruses to integrate into the host genome. b. This type of virus is called a retrovirus.

Step-by-step solution

Title - Understand the Role of Reverse Transcription

Reverse transcription is a process where the RNA of a virus is reverse-transcribed to DNA. This is essential because many host cells do not replicate RNA; they replicate DNA. Therefore, the virus must convert its RNA to DNA in order to integrate into the host cell’s genome and replicate effectively.

Title - Identify the Type of Virus

Viruses that use reverse transcription in their life cycle are known as retroviruses. This classification is due to the presence of reverse transcriptase, an enzyme that catalyzes the process of reverse transcription from RNA to DNA.

Key concepts

RNA Virus

RNA viruses are a category of viruses that have ribonucleic acid (RNA) as their genetic material. Unlike DNA viruses that use DNA for their genetic information, RNA viruses rely on RNA to encode their genetic instructions. This group includes a wide array of viruses, including the flu virus and the Ebola virus.

One of the main characteristics of RNA viruses is the presence of their genetic material as single or double-stranded RNA. This RNA can carry out the same functions as DNA in terms of storing genetic information, but it often has to be converted into a form that the host cell can use to create viral proteins and replicate the virus.

Because host cells primarily operate using DNA rather than RNA, RNA viruses often need to undergo processes such as reverse transcription to successfully replicate within the host.

Retrovirus

A retrovirus is a specific type of RNA virus that uses an enzyme called reverse transcriptase to convert its RNA into DNA once it infects a host cell. This reverse transcription process is essential for the virus' ability to integrate its genetic material into the host's DNA.

After integration, the viral DNA is able to hijack the host's cellular machinery to produce new virus particles. Examples of retroviruses include the Human Immunodeficiency Virus (HIV) and certain types of leukemia viruses.
Retroviruses are unique because this integration into the host DNA allows them to persist in the host for an extended period, sometimes even becoming a permanent part of the host's genetic material. This makes them particularly challenging to treat and eradicate.

Reverse Transcriptase

Reverse transcriptase is an enzyme that retroviruses use to convert their RNA into complementary DNA (cDNA). This process, known as reverse transcription, is crucial for the life cycle of retroviruses.

The enzyme works by synthesizing DNA from an RNA template. This newly formed DNA can then integrate into the host cell's genome. The enzyme's ability to perform this function is what enables retroviruses to reproduce and propagate within a host.

Reverse transcriptase is a target for antiviral drugs. For example, reverse transcriptase inhibitors are used in the treatment of HIV to block the replication of the virus. By interrupting the reverse transcription process, these drugs help in controlling the spread of the virus within the body.