Bacteria

2 Domains of Bacteria

Archaea Bacteria Domain (Ancient Bacteria)

• Live in extreme environments: without oxygen,ocean floors, salty water, hot springs, cow intestines,swamps.

Eubacteria Domain (True Bacteria)

• Live everywhere.• Cyanobacteria (blue-green algae) –contain chlorophyll, live in water, return nitrogen tothe soil; green pond scum

Characteristics of Bacteria

1. Unicellular = single-celled.

2. Prokaryotes: Cell DNA notcontained in a nucleus.

• DNA is circular shape.

3. Surrounded by a cell wall.

4. May have flagella to move.

Some bacteria have flagellafor movement.

Bacteria vary greatly in size.

3 Basic Shapes of Bacteria

Bacilli = rod-like

Spirilla = spiral

Cocci = round

Bacilli

Cocci

Spirilla

Survival Needs of Bacteria

Obtain Food

1. Autotrophs: make their food.

• Photosynthesis

• Use chemical substances in their environment.

2. Heterotrophs: cannot make their own food.

• consume other organisms.

• consume foods.

• consume dead organisms.

Respiration1. Break down food to release energy.

2. Some require oxygen = aerobes.

glucose + oxygen carbon dioxide + water + energy

C6H12O6 + O2 6CO2 + 6H2O + 36 ATP energy

3. Some do not require oxygen = anaerobes.

glucose lactic acid + energy

C6H12O6 2C3H6O3 + 2 ATP energy

Reproduce

• reproduction that involves only one parent• offspring are identical to the parent

Binary Fission: cell divides to form two identicalcells

1. Asexual Reproduction:

Binary Fission

2. Sexual Reproduction:

• reproduction that involves two parents• offspring is different from both parents

Conjugation

• genetic information is exchangedbetween organisms

• does not increase the number of bacteria• results in bacteria that are genetically different

Conjugation

3. Endospore: a small, rounded, thick-walled,resting cell that forms inside a bacterial cellwhen conditions are not good enough toreproduce.

• helps bacteria survive harsh conditions byresisting, freezing, heating, drying

Anthrax endospores

The Role of Bacteria and

Nature

Cyanobacteria

1. Oxygen Production.

2. Food Production

Pasteurization: food is heated to a temperature high enough to kill most harmful bacteria without changing the taste of the food.

3. Bacteria as EnvironmentalRecyclers

4. Environmental Cleanup: Bioremediation

Oil eating bacteria.

5. Health and Medicine

• Help digest food in your intestines.

• Make vitamins your body needs,such as, vitamin K needed forblood clotting,

• Make medicine such as insulin.

Familiar Diseases

Strep throat

Strep Throat

Blood Agar Plate testing positive for

Streptococcus pyogenes

Pneumonia

Bronchitis

Subcutaneous, Respiratory, or Gastrointestional

Tetanus

Tuberculosis

Lyme Disease

Food Poison

E. coli

Salmonella

Clostridium botulinum

Shigella

Antiobiotic: a chemical that can kill bacteria without harming a person’s own cell.