Exam 6.1-6.3 Microbio portage learning

Viruses are small, non-cellular particles that cannot replicate unless inside a living host cell.

(1) genomic material comprised of either DNA or RNA and (2) a capsid, a membrane-like protective structure that contains the genetic material, similar to the nucleus of a eukaryotic cell.
genome can vary in size form a 7,700 to 2.5 Million nucleotides

is a lipid coating structure surround the capsid fromed from budding frim host cell and taking parts its lipid membrane in the process

virons are uneveloped because they are lysed from the cell

Glycoprotein extensions that identify and bind to host cell proteins mutating genomes can change the spike protein of a virus
ID and bond to host cells, it gives it specificity, produce vaccines

to host via capsid proteins for naked viruses or spiked proteins for enveloped

1.Prior to budding viral envelope protein are assembled in the cell membrane
2. the virion then picks up the host cell's plasma membrane and any proteins in it. it advantageous for the virus because now it looks like the host and can aviod immune dection
3. a new enveloped amd released virus can infect anther host cell and repeat cycle

the virus quickly replicates, the immuune system clears it fast and there is rapid recovory

replication peaks and decrease making it diffcult for the immune system to clear the infection
productive infection ---Times of viral relication are called:
silent infection--> when relication is low
EX. HPV, chicken pox

Viral replication is low enough there are no symptoms. However, the host may still be infectious during the quite period. Ex. HIV

only infect bacterial cells, not human. Can kill prokayotic cells may be used to kill bacteria when antibiotics not longer work.
virus does not pass its capsid into the host cell. Instead, once the tail fibers have mediated binding, the helical tail penetrates the host cell wall and the viral genome is effectively injected through the hollow helical tail and into the cytoplasm as shown in

bacteriophages replicate within the host bacteria until it lyses, or ruptures, effectively destroying the host bacterial cell. The quantitative amount of virus present in the culture is referred to as the viral titer

s what allows researchers to carefully and effectively plan infectious experiments—too much virus will cause it to immediately overwhelm and kill the host cells, while too little virus will take too long to generate detectable levels of newly produced virus.
pahe may enter lytic cycle if the host cell is stressed

attachment: don't have the abiluty to move so they randomly attach

entry: injects its genome into the host; empty capsid remain outside cell

replication: protein sythesis makes phages parts and genome is replicated; host cell DNA is broken down by bacteriophage DNAases

Assembly: 100-1000 genome packed into capsid and phage structure assemmbled

Released: Bacterial cell lyses and new phages are released

measures the cloudiness of solution
lots of bacterial cells high turbidity
if there are phages low turbidity because they have eaten the bacteria
measures the amount of the light that passes through

the specific ability of a virus to preferentially infect and replicate within particular host species, organs, tissues, or cell types. Ex. Ebola is broad tropism

Fusion: There is fusion of the viral envelope and host cell membrane as they are both made of the same materials. ONLY envelpoed
endocytosis: Virus is endocytosed into an endocytic vesicle (endosome) with cellular enzymes ENVELOPED and NAKED

bacteriophages can exist in a non-replicative state such that its viral genome is integrated into the host genome. Upon integration into the host genome, the phage is referred to as a