Bacteria VS Virus

Bacteria (singular: bacterium) are unicellular microorganisms. They are typically a few micrometers long and have many shapes including curved rods, spheres, rods, and spirals.

A virus (from the Latin noun virus, meaning toxin or poison) is a sub-microscopic particle (ranging in size from 20–300 nm) that can infect the cells of a biological organism.

Virus - Bacteria Differences

• Viruses are the smallest and simplest life form known. They are 10 to 100 times smaller than bacteria.
• The biggest difference between viruses and bacteria is that viruses must have a living host - like a plant or animal - to multiply, while most bacteria can grow on non-living surfaces.
• Bacteria are intercellular organisms (i.e. they live in-between cells); whereas viruses are intracellular organisms (they infiltrate the host cell and live inside the cell). They change the host cell's genetic material from its normal function to producing the virus itself.
• There are some useful bacteria but all viruses are harmful.
• Antibiotics can kill bacteria but not viruses.
• An example of a disease caused by bacteria is strep throat and an example of an affliction caused by a virus is the flu.

Comparison chart

Ribosomes	BACTERIA Present	VIRUS Absent
Living attributes	Living organism	Opinions differ on whether viruses are a form of life or organic structures that interact with living organisms.
Number of cells	Unicellular; one cell	No cells; not living
Structures	DNA and RNA floating freely in cytoplasm. Has cell wall and cell membrane.	DNA or RNA enclosed inside a coat of protein.
Cell wall	Peptidoglycan/Lipopolysaccharide	No cell wall.Protein coat present instead.
Treatment	Antibiotics	Vaccines prevent the spread and antiviral medications help to slow reproduction but can not stop it completely.
Enzymes	Yes	Yes, in some
Nucleus	No	No
Virulence	Yes	Yes
Infection	Localized	Systemic
Benefits	Some bacteria are beneficial (e.g. certain bacteria are required in the gut)	Viruses are not beneficial. However, a particular virus may be able to destroy brain tumors (see references). Viruses can be useful in genetic engineering.
Reproduction	Fission- a form of asexual reproduction	Invades a host cell and takes over the cell causing it to make copies of the viral DNA/RNA. Destroys the host cell releasing new viruses.
Size	Larger (1000nm)	Smaller (20 - 400nm)