Question

Objective: At this point, you should be developing the skills to become a self-learner. The objective of this extra credit assignment is to provide a topic, using your background knowledge, you can learn independently: viruses Background: Viruses are considered to be at the borderline of life because they have the ability to reproduce, but they lack a nervous system. Viruses reproduce by infecting cells and "hijacking" the mechanisms in the cell to replicate, meaning that they make more copies of the virus. The cell eventually lyses and the new copies of the virus are released, which go on to infect other cells until the immune system can stop the process. The following questions are intended to provide a brief introduction of the structure of viruses and how they replicate. You may use any resources available to complete the following problems 1. A typical virus structure has two/three parts. Describe the structure of the following parts and what they do when a virus infects a cell. Genome: Capsid: Envelope (not found on every virus): 2. The genetic material in a virus may be DNA or RNA. Describe how the replication process after infection for a RNA virus and a DNA virus is different. Hint: look for an enzyme named "reverse transcriptase".

Answer 1

Answer: -

Genome: -viruses have only one type of nucleic acid i.e either DNA or RNA but never both. So they are classified accordingly as DNAor RNA viruses. The nucleic acid can be single stranded, double stranded, circular, linear or segmented. They contain genes which code for protein so they help in synthesis of several viral proteins and they can also replicate and assemble with the proteins to form new vision.

Capsid: -capsid is composed of a number of repeated protein subunits called caosomeres. They protect nucleic acid from external environment, it is also antigenic for each virus

Envelop: -some viruses posses a envelop surrounding the nucleocapsid which is lipoprotein in nature. The lipid part is derived from host and protein from virus. The protein part made up of subunits called peplomers which are antigenic and bind to host receptors.