Viruses & Bacteria

A guide to understanding the similarities and differences of viruses

and bacteria

Two Bacteria Kingdoms

• Archaebacteria

• Eubacteria

Archaebacteria

• Ancient life form• Live in extreme

environments• More than 300 million

years old.

Eubacteria

• Most abundant form of life on Earth.

• Make foods, cause diseases and decompose matter.

• Live in warm, pH balanced, low-salt environments.

• Different cell walls and RNA than Archaebacteria.

Viruses

• Greek word meaning “to poison”.

• Measured in nanometers (nm).

• A nanometer is = to 1 billionth of a meter.

• Viruses have 2 parts: a core of genetic material and a protein coat.

• A bacteriophage is a type of virus that infects a bacteria.

Bacteriophage

• It is a virus.• It attaches to bacteria

with it’s tail.• It sends it’s genetic

material from it’s head to it’s tail.

• More of the virus reproduces in the host bacteria.

Viruses come in many shapes and sizes!

• Viruses range in size from 10-250 nm.

• They do not have cells.

• They are non-living.

• They contain hereditary material (DNA or RNA).

• Must have a host cell to survive.

• Strong protein coat.

                   

How viruses multiply

• Active Virus Steps:1. Virus attaches to cell

2. Injects genetic material

3. Genetic material takes over cell function

4. New viruses form

5. Viruses burst out of cell.

• Hidden Virus Steps:1. Virus attaches to cell

2. Injects genetic material

3. Genetic material of virus becomes part of cell’s genetic material.

4. After some time, virus genetic material removes itself and becomes active.

5. New viruses form

6. Viruses burst out of cell.

Bacteria

• Kingdom: Moneran has been split into the Acheabacteria Kingdom and the Eubacteria Kingdom.

• Unicellular organisms.• Oldest form of life on Earth.• First found by van Leeuwenhoek in the

1600’s.

Characteristics of Bacteria

• Prokaryotes, no nucleus

• Cell wall for protection

• Cell membrane controls what enters cell.

• Cytoplasm contains genetic material and other organelles

• Ribosomes make protein

• Flagellum used for movement

Movement of Bacteria

• Bacteria move with Flagella.

• These are tail like structures that help the bacteria to move in liquid.

Three shapes of bacteria

• Spirilla (spigh-RIHL-uh)

• Spirillum (singular)

• Cork-screw shaped.

Cocci

• Cocci (KAHK-sigh)

• Coccus (singular)

• Spherical shaped

Bacilli

• Bacilli (buh-SIHL-igh)

• Bacillus (singular)

• Rod shaped.

Obtaining Food and Energy

• Autotrophs that make food from the sun’s energy

• Autotrophs that make food from chemicals

• Hetertrophs that consume other organisms.

• Respiration: the process of breaking down food to release its energy.

Reproduction

• Bacteria reproduce by Binary Fission.

• They split in half!

• Asexual Reproduction

• Conjugation, genetic material is shared.

• Sexual reproduction

They can double in number every 20 minutes!

Endospore

• A small round thick walled resting cell formed inside bacteria.

• Protects the genetic material when conditions become unfavorable.

What Good Bacteria Does

• Oxygen production

• Food production

• Decomposers

• Environmental Clean up

• Health

• Medicine production

How Infectious Diseases Spread

• Contact with a(n)

1. infected person

2. contaminated object

3. infected animal

4.Environmental sources

Treating Infectious Diseases

• Bacteria Diseases:

• Antibiotics

• Viral Diseases

• Vaccines

• Hand washing

• Rest, fluids, good food.