Write An Essay On Hepatitis B Virus

Decent Essays
Viruses are tiny organisms that contain nucleic acid encased by a protein coat. Some are enclosed by an envelope of fat and protein molecules. This organisms cannot grow, reproduce or carry out their functions without a host cell. A virus invades living cells and uses their chemical properties in order to keep itself alive and reproduce. As they don’t have ribosomes they are not able to synthesise proteins and they are also unable to generate or store energy in the form of ATP. Therefore, they use the ribosomes of host cells to translate viral messenger RNA into viral proteins, and drive their energy and all other metabolic functions from the host cell. They also depend on the host cell for basic building materials, such as amino acids, nucleotides,…show more content…
In its infective form a virus particle is known as a virion. A virion contains only nucleic acid and does not have a structural protein. Each virion contains at least one unique protein synthesized by specific genes in its nucleic acid. Prions, which are other virus particles, are mainly composed of a protein tightly integrated with a small nucleic acid molecule.
Viruses are responsible for many common human infections and diseases. They may contain DNA as their genetic material include Herpes simplex virus and the hepatitis B virus. RNA viruses have an enzyme, known as reverse transcriptase, which enables the usual sequence of DNA-to-RNA to be reversed so that the virus can make a DNA version of itself. An illness caused by a virus include the common cold, which can be caused by rhinoviruses and AIDS, which is caused by HIV.
 The structure of viruses allows it to replicate itself and multiply within seconds. This process is called the lytic cycle where hey multiply by attaching themselves to a host cell and infuse the cell with their nucleic acid. This acid takes the host cell hostage and the virus starts to multiply with nucleic acid and its protein coat which leads to the development of new viruses. The host cell is then infected with the new viruses and it bursts. The newly formed viruses then carry on with their lytic cycle by searching for new host cells to
Get Access