Chapter 20 Viruses Part 1 Flashcards
What is a virus? Describe its basic structure.
nonliving particle made of proteins, nucleic acids, and sometimes lipids
what surrounds all viruses and what is it made of
capsids, protein coats
what does a virus have inside that has the instructions for making copies of the virus
RNA OR DNA
True or False - Viruses only come in THREE shapes and sizes, and TWO structures
False - MANY, MANY
What is on the outside of a virus that acts as identifiers?
Proteins
What do specific proteins on the outside of a virus do? Why do they do this?
they bind to specific receptors on the cells surface - they act as identifiers so that they can do this
most viruses infect a __________ cell
specific
what are viruses that only infect bacteria called
bacteriophages
why are viruses not living?
they cannot reproduce on their own
what are the two types of viral infections
lytic and lysogenic
what does it mean to lyse a cell
the cells bursts open releasing the virus particles
which of the two viruses automatically begins chopping up the host cell’s DNA
lytic infection
Which viral infection never leaves your body? Why?
Lysogenic infection bc the cell copies its DNA and viral material for generations
What is a prophage?
host and viral DNA combined together
What are the two ways that viruses cause disease?
they destroy living cells and upset homeostasis by affecting cellular processes
insert a bacteriophage - label the head, tail fibers, sheath, DNA
They are ALL CAPSIDS
ESSAY AND “SHORT ANSWER”: What are two ways that we can PREVENT viruses? Explain both in detail.
One way in which you can prevent viruses is with an injection of a vaccine. This helps to build up immunity because it injects a weakened virus or a similar but less dangerous pathogen. Washing your hands is another great way to prevent a virus. If done well, this practice dislodges viruses or bacteria from your hands so that you don’t spread them to other parts of your body as well.
What treatments do we have for viruses? Explain what is used and what they do.
Anti-viral drugs treat viruses because they stop activation by attacking specific viral enzymes that the host cell doesn’t have, to speed recovery or stop activation. An example of an anti-viral drug is tamiflu. This anti-viral works by attacking the flu virus to keep it from multiplying in your body and by reducing symptoms of the flu.
What does a virus have to have to survive? Why?
Viruses have to have living cells in order to survive. Outside of a body, they cannot survive because the capsids will begin to degrade and the likelihood of it surviving decreases rapidly.
Be able to explain how you know the difference in a lytic virus and a lysogenic virus.
The lytic cycle involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell. The lysogenic cycle involves the incorporation of the viral genome into the host cell genome, infecting it from within.
THE LYTIC AND LYSOGENIC CYCLE OF BATERIOPHAGES IS YOUR TITLE FOR THE DIAGRAM - study over the diagram like crazy bc there is a lot of things on it and i cannot type them all on here
try to memorize most of it or at least key words
