BACTERIA

Bacteria are very small

Pore in the human skin The yellow spheres are bacteria

Bacteria about to be eaten by a white blood cell

Clean skin has about 20 million bacteria per square inch

The tip of a needle The red and yellow dots are bacteria

Bacteria on a toothbrush

Basic Characteristics Unicellular Prokaryotic  Lack a nucleus  Lack membrane- bound organelles Have a cell wall

Structure

2 Kingdoms Archeabacteria  Live in harsh conditions  Cell wall lacks peptidoglycan Eubacteria  More diverse  More common  Cell wall contains peptidoglycan

Archeabacteria - Methanogens Live in anaerobic conditions Produce methane Found in the digestive tracts of cows & termites

Archeabacteria - Thermophiles Thrive in extremely high temperatures Hot sulfur springs, volcanic vents

Archeabacteria - Halophiles Thrive in extremely salty conditions Dead Sea, Great Salt Lake

Eubacteria Most bacteria are in this kingdom Found just about everywhere on the planet Almost as old as Archeabacteria Responsible for initial presence of oxygen in the atmosphere

3 Bacterial Shapes

1. Cocci = Sphere

2. Bacilli = Rod

3. Spirilla = Spiral

Strepto = Chain

Staphylo = Cluster

3 Methods of Obtaining Nutrition Photo- autotroph Chemo- autotroph Heterotroph

Photoautotrophs Use light to produce energy/food

Chemoautotrophs Use inorganic compounds to create usable energy/ food First life?

Heterotrophs Must consume another living organism for energy/food

2 Types of Cell Walls Gram-positive Gram-negative

Gram-positive Absorbs the Gram stain Appears purple under the microscope

Gram-negative Do NOT absorb the Gram stain Appear pink under the microscope Have a lipid outer coat Increased resistance to antibiotices

Reproduction 2 Types: Asexual & Sexual

Asexual = Binary fission DNA copies Cell divides

Sexual = Conjugation Use pili Transfer plasmids * Increases genetic diversity

Bacteria maybe helpful or harmful Cause disease Recycle nutrients  Nitrogen-fixation Food Medicine Aid with digestion

Just a quick review ….

Helicobacter pylori = ulcers

Botulism/Botox

Cholera

Salmonella

Dental caries

Strep throat

Lyme Disease

leprosy