bio: viruses

viruses and viroids

nonliving particles with nucleic acid genomes that require the assistance of living cells to reproduce

host range

the number of species that can be infected

host cell

number/types of cells infected by a virus

capsid

protein coat that encloses the nucleic acid, composed of one or more protein subunits called capsomers

viral envelope

encloses the capsid, liquid bilayer, may have glycoprotein

virus

small infectious particle that consists of nucleic acid enclosed in a protein coat, some may have an envelope

viral reproductive cycle

attachment, entry, integration, synthesis, viral assembly, release

lysogenic cycle

phage genome integrates into host chromosome as prophage, when host cell replicates prophage replicates, excision leads to lytic cycle

lytic cycle

steps that lead to synthesis, assembly, and release of virus

temperature phages

can have lysogenic cycle or lytic cycle

virulent phages only have a…

lytic cycle

virus latency

integrates into host genome and may remain dormant for long periods of time; episomes are genetic elements that replicate independently of host DNA

emerging viruses

have arisen recently or are more infectious due to mutation

viroids

RNA that affects plants

prions

proteins that affect animals

prions effect

prions affect normal proteins by becoming into contact with them and turning them into another prion

dsDNA

bacterial chromosome

nucleiod

region where tightly packed bacterial chromosome is found

plasmids

small circular pieces of DNA that exist independently of the chromosome

vertical gene transfer

when genes are passed from one generation to the next

horizontal gene transfer

when genes are passed to non-offspring, dieases

bacterial strain

lineage that has genetic differences from another lineage

3 ways to transfer genes between bacteria

conjugation, transformation, transduction

conjugation

direct contact between donor and recipient

transformation

dna fragment from donor is released in the environment and taken up by recipient

transduction

bacteriophage infects donor and picks up donor dna to infect new cell and transfer dna to recipient

recombinant dna technology

use of laboratory techniques to bring together fragments of dna from multiple sources

genomics

molecular analysis of the entire genome of a species

vector

carrier for pathogen or transmitting genetic material into host, plasmids

plasmid dna

small, circular, sel-replicating dna found in bacteria

restriction enzymes

enzymes that will cut dsDNA at a specific sequence, creating sticky ends

PCR

polymerase chair reaction, enzymatic reactions that will make millions of copies of a dna of interest

ligase

enzyme that joins 2 dna fragments together, closes the gap

viral vectors

derived from viruses which infect living cells and propagate themselves using the host cell’s machinery

what happens in PCR

repeated rounds of denature, anneal, and extend… splitting apart nucleotides, filling in with new complement, and extending it