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VIRAL REPLICATION

VIRAL REPLICATION. Viruses replicate in one of two ways: Lytic Lysogenic. Lytic Cycle . For each step use the description and picture to determine a verb that would describe what is going on in each step. . Lytic Cycle .

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VIRAL REPLICATION

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  1. VIRAL REPLICATION Viruses replicate in one of two ways: • Lytic • Lysogenic

  2. Lytic Cycle • For each step use the description and picture to determine a verb that would describe what is going on in each step.

  3. Lytic Cycle • 1.Proteins on the surface of the virus bind with proteins on the surface of the host cell  this is specificity • 2.The Virus injects its DNA into the host cell • 3.The DNA from the virus shuts down and takes over the host cell • 4.The virus uses the materials of the host cell to make thousands of copies of its own protein coat and DNA • 5. The cell lyses (bursts) and the releases hundreds of virus particles

  4. LYTIC CYCLE Virus attaches to host cell. Virus injects its DNA Cell lyses (breaks apart) and new viruses are released Virus DNA commands host cell to make new viral parts New viral parts assembled

  5. Lysogenic cycle

  6. Lysogenic cycle • 1.Proteins on the surface of the virus bind with proteins on the surface of the host cell  this is specificity • 2.The Virus injects its DNA into the host cell • 3.The viral DNA is inserted into the host cell’s DNA • 4.The viral DNA is now known as a prophage • 5.The prophage may remain as part of the host cell for many generations • 6.The inserted DNA may be useful. It can block other viruses from entering the cell or create useful proteins • 7.Eventually the viral DNA removes itself from the DNA of the host cell and start reproducing viruses

  7. Both cycles together

  8. Lytic or Lysogenic?! • Rules of the game- • I am going to read out a description • If I am describing a lytic cycle go to the left side of the room and stand • If I am describing a lysogenic cycle go to the right side of the room and stand

  9. Epstein-Barr virus • The Epstein-Barr virus (the larger dark sphere in the photo at the left) infects up to 95 percent of adults, which means you probably have it. This virus is normally picked up in early childhood. However, most people don't know they have it; usually it just sits in your body quietly. • In some people, however, the virus becomes active, usually in the teenage years. The virus causes the sickness called mononucleosis, which can be spread by saliva (giving it the nickname 'the kissing disease'). It is also commonly referred to as Mono.

  10. Influenza • The influenza virus causes acute upper respiratory disease in humans, usually accompanied by a fever. These viruses are roughly spherical, and about 200 millionths of a millimetre in diameter. Once they enter a host they immediately attack and hijack the host’s cells making numerous replications of themselves. In the process the virus kills the cell and then invades an adjacent cell repeating the same process over and over.

  11. Enterovirus • Enteroviruses belong to one of the largest families of viruses; others in this family include rhinoviruses (which cause the common cold), cardioviruses, apthoviruses and hepatoviruses (which cause hepatitis A). Enteroviruses usually reproduce in the intestine. An important enterovirus is the one which causes polio. Once they enter a host they immediately attack and hijack the host’s cells making numerous replications of themselves. In the process the virus kills the cell and then invades an adjacent cell repeating the same process over and over.

  12. Hepatitis B • Hepatitis B virus causes both acute and chronic liver infections in humans. An unusual feature of these infections are the length of time they last; up to several months in acute infections, and many years (or for life) in chronic infections.

  13. Adenovirus • The adenovirus consists of a slender shaft with a globular head. Adenoviruses can infect humans, and can cause respiratory illness or conjunctivitis ('pink eye'). Once the host has been infected the virus attaches and injects it’s genetic material into the host cell. The genetic material is not added to the host’s DNA and instead hijacks the hosts cell to make many replicas of itself.

  14. Papillomavirus • The papillomavirus attacks human cells, and can cause ordinary warts, which are harmless. But some varieties cause genital warts; these tumours can become malignant. Once infected a Human host can have multiple outbreaks resulting in warts through out their entire life.

  15. Controlling viruses • Antibodies DO NOT work on viruses • Most human viral infections can be fought off by the immune system • Boost the immune system with lots of water and rest • Vaccines are preventative

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