BACTERIA

Bacteria on the tip of a pin!

Composed of One, circular chromosome Plasma membrane Ribosomes Cell wall with peptidoglycan

Composed of Some have –Capsule Slimy outer layer –Flagella –Pili Straw-like extensions Allow bacteria to stick to host Some allow conjugation –Exchange of plasmids

Flagella

Conjugation

Composed of Some have –Plasmids Only in some bacteria Tiny circles of DNA Only a few genes

PROKARYOTIC No membrane-bound organelles Smaller than eukaryotes All unicellular

Reproduction Binary Fission –Chromosome is replicated –Cell elongates and then splits in two –NO MITOSIS NECESSARY

METABOLISM Some heterotrophic Some autotrophic –Photosynthesizers –Chemosynthesizers Can get energy from non- organic compounds: ex H 2 S, NH 3

METABOLISM Some Aerobic –Require O 2 Some Anaerobic –Obligate anaerobes Killed by O 2 –Facultative anaerobes Can exist with or without O 2

METABOLISM Some secrete TOXINS –Chemicals that are poisonous to eukaryotic cells –Ex: Tetanus, botulism

COLONIES Large clumps of thousands of bacteria all grown from one ancestor Are genetically identical Each species has colonies with particular characteristics such as color, shape, texture

COLONIES

BACTERIAL SHAPES Coccus – Round Bacillus – Rod-shaped Spirillum – Spiral-shaped Vibrio – comma-shaped

Vibrio

GROUPINGS Micro – individual Diplo – pairs Strepto – chains Staphylo - clusters

Diplococcus

Staphylococcus

Streptococcus

Streptomyces

ENDOSPORES Hard-shelled case built around DNA during harsh conditions

ENDOSPORES

Gram Staining Gram Positive – Blue –No capsule Gram Negative –Red –Capsule

Gram Staining

Helps doctor decide which antibiotic to use

Uses of Bacteria Ecosystems –Decomposers –Nitrogen fixation –Oil eaters Foods –Chocolate, soy sauce, yogurt, vinegar

Uses of Bacteria Antibiotics and other chemicals Genetic Engineering –Plasmids used to introduce genes –Insulin, growth hormone

Antibiotics Interfere with bacterial metabolism Are not effective against viruses Used to treat bacterial diseases Penicillin, erythromycin, tetracycline, sulfa drugs, cephalosporins, etc.

Vaccinations Small amount of inactivated virus or bacteria injected or ingested Immune system mounts long- lasting response Prevents rather than treats disease Measles, mumps, rubella, polio, chicken pox, meningitis, HPV, hepatitis, diphtheria, pertussis, tetanus