Antiviral Medication, Influenza, HIV AIDS Flashcards
What are viruses?
contain 2 main components:
- protein coat (capsid)
- DNA or RNA (carried in capsid)
together these are the nucleocapsid
mutate rapidly
countered by vaccines that prepare specific antibodies which can give immunity (bodies may need a booster to rechallenge the immune system, reselect for antibodies effective against a particular virus)
How does the body respond to viral infections?
Producing specific antibodies which act against a virus in the immune response; leads to protection (immunity) against repeated infections with the same virus
How do antiviral medications work?
viruses are only capable of reproducing inside another living cell
inhibit the activity of enzymes that are necessary for the formation of new viruses
preventing viruses from binding to the host cell surface and gaining access into the cell
prevent the virus from leaving the host cell
What is influenza?
flu caused by two different types of viruses: influenza A and B (both spherical and have RNA as their genetic material)
flu viruses have specific proteins on their surface, which play a key role in their life cycle
hemaglutinin (H); a glycoprotein that enables the viral particle to “dock” with the host cell before it enters
neuraminidase (N); enzyme that catalyzes a cleavage reaction, allow new viral particles to escape from the host cell and spread infection
Which of the two proteins is a better target for drug design?
How does it work
neuraminidase binds to its reactant sialic acid (substrate) at the active site; binding gives a catalytic action, provides a reaction pathway of lower activation energy
What is HIV AIDS?
primarily infects vital white blood cells in the immune system, called CD4+ T cells
virus binds to specific receptor proteins on the cell surface, then penetrates the cell
HIV is a retrovirus, its genetic material is in the form of RNA
How does HIV work?
releases RNA into the cell, and the enzyme reverse transcriptase controls the synthesis of viral DNA from RNA.
Viral DNA integrates into the cell’s own DNA and replicates with it when the cell divides, viral particles produced in the host cell
Why is HIV difficult to treat?
the virus destroys helper T cells (these cells should be defending the body against the virus
the virus tends to mutate very rapidly, these variations escape the immune response, so the patient has to make a new response to the new virus
virus often lies dormant within host cells, so the immune system has nothing respond to
