Flashcards in Lecture 14 Deck (60)
What is even the smallest bacteria capable of?
independent replication, synthesis of energy and proteins, cell enclosed with DNA and RNA
What do viruses not have?
cell wall, cytoplasm, ribosomes/mitochondria, nucleus, independent replication
Does nature have RNA carrying genetic information?
NO- not found in nature
Will viruses contain DNA and RNA?
Not both at the same time- one or the other
DO RNA viruses carry genetic information?
Can virues synthetize their own energy or proteins?
Can viruses be seen under a microscope?
NO- too small
How do antibiotics affect viruses?
THey are resistant to all antibiotics
What did Geirer and Schraman do?
extracted the infectious nucleic acid which produced disease in the host cells confirming it as living chemicals
Most viruses are what shape?
extracellular virus particles- vary in size from 20-300nm
What is the biggest virus equal to?
the size of the smallest bacteria (micro plasm)
List shapes of viruses
spherical, complex, bullet shaped/brick shaped
What can viral nucleic acids be extracted with?
What parts make up the viral structure?
central nucleic acid, protein coat (capsid), some may have an envelop
What part of the virus protects the nucleic acid and is the basic structure of a virus?
capsid- facilitates absorption
What is the envelop of the cell made up of?
envelop is a lipid layer derived from host cell during budding
Are viruses heat labile?
At what temperature are viruses inactivated within a few seconds?
56 degrees celcius
What inactivates viruses?
sunlight, UV light
What are viruses resistant to?
chemical disinfectants- lysol for example
How doe viruses replicate?
disassemble into patricles inside the cell, multiply separately and then assemble- one virion giving rise to hundred of virion particles
Process of adsorption of a virus
virus adsorbed to host cell- there are specific receptors on host cell for viruses
Penetration of a virus
penetrate into the cell
Uncoating of a virus
stripping of virus from capsid by lysozyme of the cell
Process of virus attacking
absorption, penetration, uncoating, biosynthesis, maturation, release
Process of biosynthesis of virus
synthesis of enzymes for stages of viral replication, assembly and release. Followed by synthesis of nucleic acid and capsid protein takes place separately
Where does synthesis of nucleic acid take place?
Where does synthesis of viral proteins occur?