BACTERIA

KEY CONCEPTS

1. LIVING UNICELLULAR ORGANISMS

2. PROKARYOTIC = NO NUCLEUS

CONSISTS OF 2 KINGDOMS: EUBACTERIA AND ARCHAEBACTERIA

EubacteriaLarger kingdom

(more members)CommonLive everywhereHave

peptidoglycan in cell walls

3. ArchaebacteriaSmaller kingdomLive in extreme

environments:ThermophilesHalophilesMethanogens

May be ancestors of eukaryotes (DNA is similar)

Lack peptidoglycan

3 KINDS OF ARCHAEBACTERIA

HALOPHILES (SALTY WATER)

THERMOPHILES (HOT)

METHANOGENS (COW INTESTINES, produce methane)

CLASSIFICATION OF BACTERIA

What shape they are.What type of cell wall they

have.Their movement

characteristics.Their specific mode of

nutrition.The way they get energy

(ATP) from food.

3 SHAPES OF BACTERIA

COCCI

BACILLI

SPIRILLA

4. Bacillus (Bacilli)

4. Coccus (Cocci)

4. Spirillum (Spirilla)

Prefixes

4. Diplo = 2

Strepto = chain

Staphylo = clumps

Cell Wall Type: Gram stainingUsed to find out which type of

cell wall a eubacterium has.Gram + has a thick

peptidoglycan cell wall. (purple)5. Gram – had a thinner cell

wall with an outer lipid layer. (pink/red) Can be antibiotic resistant

Types of Movement

6. Flagella: tail used for movement

Cilia: short hairlike projections

Pili: used for cell-to-cell contact

Some glide, wiggle, slide.Some do not move at all.

Types of Nutrition

Autotrophic: makes own food7. Chemoautotroph: uses chemicals

Photoautotroph: uses sunlightHeterotrophic: consumes food

(most)Chemoheterotroph-takes in organic molecules

Photoheterotroph (are photosynthetic and take in compounds)

Releasing energy from food:8. Obligate aerobe: require

oxygenObligate anaerobe: must live in

the absence of oxygen (ex: Clostridium botulinum-in canned food)

9. Facultative anaerobe: can survive with or without oxygen (E. coli-lives anaerobically in lg. intestine, but aerobically in sewage or contaminated water)

REPRODUCTION (p. 475)

10. Binary fission: asexual, splits in two

11. Conjugation: sexual, exchange genetic info through a hollow bridge that forms between two bacterial cells

12. Spore formation: when conditions unfavorable, spore forms around DNA to protect it (endospore)

BENEFICIAL BACTERIA13. MOST BACTERIA ARE HELPFUL

(like in our intestines!)14. DECOMPOSERS, recycle

nutrientsBIOREMEDIATION: DIGEST

HARMFUL CHEMICALS, like oilNITROGEN FIXATION: IN LEGUMES

(SUCH AS SOYBEANS)FOOD: YOGURT, CHEESE, PICKLES,

SOUR CREAM, BUTTERMILK, ETC.

15. BACTERIA AND ILLNESSES

ANTHRAXTETANUSTooth decayStrep throatCHOLERA: SPREADS BY

CONTAMINATED WATERStaph infectionBUBONIC PLAGUE: DISEASE

CARRIED BY RODENTS TO HUMANS

Food poisoning……

SalmonellaE. coliBotulism

PathogensBacteria can cause disease in

two ways:16. Produce toxinsDamage cells

Control—prevent bacterial growth

17. Sterilization: heat, disinfectants

Food processing: boiling, canning, salting, refrigeration (doesn’t kill, just slows down)

Antibiotic: medicine that kills bacteria

Antibiotic Resistance

Many bacteria have evolved resistance to antibiotics, so we are constantly having to change antibiotics.

Antibiotic resistance article link18. Describe what it means…