bacteria & virus
DESCRIPTION
A 10 Slides presentation on just the surface of the virus and bacteriaTRANSCRIPT
GENERAL CHARACTERISTICS OFVIRUS & BACTERIA
Anand Charvin & Bhakar Ningombam
BACTERIAL CHARACTERISTICS
Bacterial Characteristic
s
Bacteria are of immense importance because of
their rapid growth, reproduction, and
mutation rates, as well as, their ability to exist
under adverse conditions.
The oldest fossils known, nearly 3.5 billion years
old, are fossils of bacteria-like organisms.
Bacteria
Autotrophs Heterotrophs
• Those that are classified as autotrophs are either photosynthetic, obtaining energy from sunlight or chemosynthetic, breaking down inorganic substances for energy .
• Bacteria classified as heterotrophs derive energy from breaking down complex organic compounds in the environment.
• This includes saprobes, bacteria that feed on decaying material and organic wastes.
BACTERIA STRUCTURE AND TYPES
BACTERIA
• Bacteria are often maligned as the causes of human and animal disease. However, certain bacteria, the actinomycetes, produce antibiotics such as streptomycin and nocardicin.
• Bacteria live on the roots of certain plants, converting nitrogen into a usable form.
• Bacteria make up the base of the food web in many environments.
About:Bacteria
Bacteria are prokaryotic
and unicellular.
Bacteria have cell walls.
Bacteria have circular DNA
called plasmids
Bacteria can be anaerobes or aerobes.
Bacteria can be
heterotroph or autotroph
Bacteria can be useful as
well as pernicious.
GENERAL CHARACTERISTICS OF VIRUS
Viruses are infectious agents with both living and nonliving characteristics.
1. Living characteristics of viruses
a. They reproduce at a fantastic rate, but only in living host cells.
b. They can mutate.
2. Nonliving characteristics of viruses
• They are a cellular, 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.
GENERAL STRUCTURE OF VIRUS
Viral components• Nucleic acids• Capsid• Envelope
CHARACTERISTICS OF VIRUS
Virion (Virus particles) size range
is ~10-400 nm
All virions contain 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
THE ENVELOPE
Many viruses that infect humans and other animals are enveloped.
Envelopes form when viral glycoproteins and
oligosaccharides associate with the plasma membrane of the
host cell.
All envelopes have a phospholipid bilayer.
VIRUS CLASSIFICATION