Virus replication

you either get disease of host cell or genetic alteration of host cell

a productive infection - (more virus is produced)

1. lysis of cells which releases the virions and the host cell dies
2. release of virions-non-lysis of cells so then there is a continucus leakage of virions due to host cell multiplies

Latent state-nucleic acid of virus becomes part of host cell DNA which means the host cell is often modified and continues to multiply

only a limitd cell types or species are able to support productive infection or replication of some viruses

is it takes place within the host cell and relies primarily on the metabolism of the host cell

adsorption, penetration, uncoating, transcription, translation, synthesis of nucleic acids, assembly of new viral particles, and egrass

it involves attachment between viral envelope using surface glycoprotein (peplomers) and specific receptors on the cell surface.

the attachement tkes place between specific capsid proteins and cell receptors

enveloped viruses penetrate cell by fusion of the viral membrane with cell membrane, thereby releasing the nucleocapsid directly into the cytoplasm.

Naked virus penetrate the cell by phagocytosis (viropexis) of the virion from the extracellular fluid. The virion resides within a vacuole, which eventually dissolves, releasing the virion into the cytoplasm.

it takes place in the cytoplasm where cell enzymes attach and partially remove the capsid structure.

cellular proteases

not really

the beginning of eclipse phase of replication which is a phase when infectious virus cannot be dected

Adsorption, penetration and uncoating

the viral DNA migrates to the host nucleus and enters through a nuclear pore.

the viral DNA is transcribed by host cell DNA dependent RNA polymerase

Viral messenger RNA (mRMA) is processed in the same manner as cellular mRNA and it is transported to the cytoplasm, where it is translated into proteins by cellular ribosomes and transfer RNA (tRNA) molecules.

Yes except for parvoviruses and papovaviruses (which is single circular DNA which replicates semiconservatively)

Begins at one or more unique sites and proceeds bidirectionally, except in adenovirus, in which the DNA replicate unidirectionally.

capsid proteins are synthesized in the cytoplasm, and migrate to the nucleus, where they aggregate into capsomers and assemble into capsid.

It is inserted into the capsid is formed

is in the host nucleus except for pox virus

in the cytoplasm

Semiconservative
conservative
dispersive

describes the method by which DNA is replicated in all known cells. You produce two copies that each contained one of the original strands and one entirely new strand

would leave the two original template DNA strands together in a double helix and would produce a copy composed of two new strands containing all of the new DNA base pairs.

Would produce two copies of the DNA, both containing distinct regions of DNA composed of either both original strans or both new strands.

Envelopes are formed around the nucleocapsids by budding from the inner layer of the nuclear membrane. The bud detaches itself and is free within the perinuclear space.

passing through the endoplasmic reticulum to the extracellular spaces or using the outer layer of the nuclear membrane to form vacuoles that contain one or more virions. These vacuoles are transported to the cell surface, where they release the virions.

They are synthesized until host cytopathology prevents production of new virions. The virions are released from the nucleus only when the nuclear membrane disintegrates and from the the cells after the cell dies.

it remains in the cytoplasm and the entire replication cycle. (which means there is no nuclear involvement except for orthomyxoviruses and retroviruses)

RNA-dependent RNA polymerase. Which does not exist in an uninfected cell. They acquire it in two ways.

Positive strand viruses and Negative strand viruses

(those that have polarity of mRNA), the parental RNA acts directly as mRNA and is translated into the RNA-dependent RNA plymerase, and ito capsid protein.

it initiates the synthesis of a complementary negative strand of RNA and the synthesis and displacement of new positive strands of RNA, some of which act as additional copies of mRNA and some are encapsidated to produce new virions

(those viruses with RNA that have polarity complimentary to mRNA), their RNA cannot act as mRNA. They required RNA dependent polymerase is brought into the cell by the virions.

the new polymerase molecules that are bound to the RNA are produced using the virus message and are incorporated into the newly produced virions

when the cell dies

released by budding through the plasma membrane. The viral envelope attaches to cell inner membrane, and budding process occurs by an out folding and pinching off of a segment of the membrane.

orthomyxoviruses, paramyxoviruses, rhabdoviruses, arenaviruses, togaviruses of the alphavirus and rubivirus

coronaviruses and flavivirus (yellow fever) of togavirus group

any virus-host cell interaction that does not lead to synthesis of new infectious virus

yes, and death if cell metabolism is interrupted

it is when the virus persis but does not replicate or destroy the cell. The total genomeof the virus is conserved, and future events can trigger virus replication

any virus-host interaction that results in heritable change in th cell. This change must be transferred to cell progeny

nay not destroy the cell, often the cells are endowed with new properties that lead to vigorous growth, to long term growth in culture and frequently to malignancy