MICROBES !!!

Viruses

Alive?

• Viruses are non-living!– They do not carry out respiration.– They do not grow or develop– Cannot reproduce without a host cell

Viral Structure

• Inner Core– Contains nucleic acid

(DNA or RNA) with instructions for making copies of the virus

• Outer protein coat called a capsid

• May have an additional layer of protein called an envelope

Viral Structure

• 4 major shapes of virus– Helical– Polyhedral– Studded Envelope– Polyhedral with leg-

like extensions

Viral Reproduction

• Lytic Cycle (eg. The flu)– Very Fast (about 30 minutes)– Takes over host cell’s genetic material – Kills the host cell quickly

• Lysogenic Cycle (HIV virus, herpes simplex 1)– Not fast– A provirus is formed-it becomes part of the host cell’s

chromosome– Changes the host cell, doesn’t kill it quickly– Can enter the lytic cycle at any time, usually because of

some sort of stress

Viral Diseases

• Herpes• Chicken Pox• Influenza• Meningitis• Measles• Mumps

Treatments for Viral Diseases

• Vaccines- alert the immune system without causing the illness

• Anti-viral drugs• Many have no cures but simply medicines

to control symptoms

Lytic Cycle

Lysogenic Cycle

Bacteria:

Classification and Structure

What are the 6 Kingdoms?

• Archaebacteria• Eubacteria• Protists• Fungi• Plants• Animals

Classification of Bacteria

• Archaebacteria: extremists• Eubacteria:

–Heterotrophs–Photosynthetic autotrophs–Chemosynthetic autotrophs

Archaebacteria

• Live in extreme locations:– Oxygen-free

environments– Concentrated

salt-water– Hot, acidic

water

Eubacteria - Heterotrophs

• Found everywhere• Parasites: live off of other

organisms• Saprobes: live off of dead

organisms or waste (recyclers)

Eubacteria: Photosynthetic Autotrophs

• Photosynthetic: make their own food from light

• Cyanobacteria: blue-green, yellow, or red

• ponds, streams, moist areas

Eubacteria: Chemosynthetic Autotrophs

• Get energy by breaking down inorganic substances like sulfur and nitrogen

• Make nitrogen in the air usable Make nitrogen in the air usable for plantsfor plants {Very Important}

Structure of Bacteria

• Two parts to Bacteria Structure:–Arrangement–Shape

Arrangement

• Paired: diplo• Grape-like clusters: staphylo• Chains: strepto

Shape

• Rod: bacillus• Spheres: coccus• Spirals: spirillum

Examples

• Streptococcus: chains of spheres• Staphylospirillum: Grapelike

clusters of spirals• Streptobacillus: Chains of rods

Bacterial Diseases

• Pneumonia• Strep Throat• Meningitis• Salmonella• Cholera• Bubonic Plague

Treatment

• Bacterial infections can usually be treated by using antibiotics.– The first antibiotic was Penicillin which was

discovered by Alexander Fleming in 1928.– Penicillin is derived from a fungus and works

by eating holes in the cell wall of the bacterial cells