BIO CH 20 Pt. 1 TEST Flashcards
what is a virus?
non living particle made of proteins, nucleic acids, and sometimes, lipids
what surrounds all viruses and wat is is made of?
capsid, made of protein
what does a virus have inside that has the instructions for making copies of the virus?
most have RNA and some have DNA . never both
TRUE OR FALSE- Viruses only come in three shapes, three sizes and two structures.
FALSE they come in 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 act as identifiers to recognize and bind to specific receptors
most viruses infect a ________ cell.
very specific
what are viruses that only infect bacteria called?
bacteriophages.
why are viruses not living?
they cannot reproduce on their own.
what are two types of viral infections.
lytic and lysogenic
what does it mean to lyse the cell?
the cell bursts open releasing the virus particles.
which of the two viruses automatically begins chopping up the host cell’s DNA?
lytic
which viral infection never leaves your body? Why?
Lysogenic bc it places DNA into host DNA
what is a prophage?
viral DNA inserted into host DNA
what are two ways that viruses cause disease?
They directly destroy living cells or affect cellular processes in ways that upset homeostasis.
BE ABLE TO LABEL THE T4 BACTERIOPHAGE!!!!
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what are two ways that we can prevent viruses? explain both in detail.
You can get a vaccination. A vaccination is an injection of a vaccine. A vaccine is a weakened virus. Or a vaccine can be a similar but less dangerous pathogen. Vaccines are used to produce immunity in the body. Also you can practice personal hygiene by keeping yourself clean. When washing your hands you prevent the virus by dislodging viruses. After you have been sick you should change out your toothbrush for a newer one.
What treatments do we have for viruses?
We treat viruses by using anti-viral drugs. Anti-viral drugs attack specific viral enzymes that host cells do not have. These help to speed the recovery of the virus. These anti-viral drugs can stop activation.
BE ABLE TO recognize a lytic infect cycle.
be able to recognize a lysogenic infection cycle
understand each part of the lytic and lysogenic diagram from your notes.
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what happens in the first phase of the lytic virus infection, attachment?
virus proteins bind to matching responders on the cell’s surface
what happens in the second phase of the lytic virus infection, penetration?
the virus injects its genetic material.
what happens in the third phase of the lytic virus infection, biosynthesis?
host DNA chopped up and new viral proteins are made.
what happens in the fourth phase of the lytic virus infection, maturation?
the viral DNA assembles into virus particles
what happens in the fifth and final phase of the lytic virus infection, lysis?
lyse- the cell bursts open releasing the virus particles.
certain factrs determine what?
whether the lytic cycle is induced or the lysogenic cycle is entered
what happens in the lysogenic cycle first?
Phage DNA integrates into the bacterial chromosome, becoming a prophage
wat happens in the lysogenic cycle second?
the bacterium reproduces normally, copying the prophage and transmitting it to the daughter cells.
wat happens in the lysogenic cycle third?
occasionally, a prophage exts the bacterial chromosome, initiating a lytic cycle.
