BARKATULLAH UNIVERSITY BHOPAL презентация

TO :-
DEPARTMENT OF ZOOLOGY AND APPLIED AQUACULTURE

M.SC IV SEM

POWER POINT PRESENTATION

protein coat called a CAPSID.

Viruses:A
are noncellular or Acellular
infectious agents
Virology:
study of viruses

Virologists:
scientists who study viruses

VIRUS:

we define life:

* Viruses do not breathe.
* Viruses do not metabolize.
* Viruses do not grow.
* However, they do reproduce.

ASIF KANTH

nonliving characteristics.
1. Living characteristics of viruses
a. They reproduce at a fantastic rate, but only in living host cells.
b. They can mutate.

acellular, that is, they contain no cytoplasm or cellular organelles.
They carry out no metabolism on their own and must replicate using the host cell's metabolic machinery.

(not both)
Nucleic Acid is surrounded or coated by a protein shell (capsid)
Some viruses possess a membrane-like envelope surrounding the particle

enclosed in coat of protein
May have additional layers
Cannot reproduce independent of living cells nor carry out cell division as procaryotes and eucaryotes do
An intact viral particle is called a virion.

whole new viruses
Leaving the cell

ASIF KANTH M.SC IV SEM

Phase I

Phase II

Phase IV

Phase V

Phase III

I, II, III - Viruses enter cell
Attachment to cell membrane
Penetration inside cell
Losing virus protein coat

IV - Replication
Tricks cell into making more viral DNA
Tricks cell into making viral protein coat

RNA into cells, scientists are exploring Gene Therapy

In Gene Therapy, viral genetic material is replaced with new DNA

In time, this could be used to cure genetic diseases. Currently we have no cure for these types of illnesses

a nucleocapsid which is composed of nucleic acid (DNA or RNA) and a protein coat (capsid)
Some viruses consist only of a nucleocapsid, others have additional components
Envelopes
virions having envelopes = enveloped viruses
virions lacking envelopes = naked viruses

form when viral glycoproteins and oligosaccharides associate with the plasma membrane of the host cell.
All envelopes have a phospholipid bilayer.

DNA or RNA.
They infect by hijacking cells’ machinery to force them to make more viruses.
Viruses are tiny, even compared to a cell.
Some viruses may prove useful in gene therapy as natural carriers of DNA that was specially designed to be good for a particular reason.