Structure of Bacteria

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Bacteria

Chapter 18.1

1

Three Domains of

Life

Bacteria

-

Cyanobacteria and eubacteria

Archaea

habitats

– prokaryotes living in extreme

Eukarya

– Protozoans, fungi, plants, & animals

2

Characteristics of Bacteria

3

Domain Bacteria

Kingdom Eubacteria

Found just about everywhere

Strong cell walls w/ peptidoglycan

Some have a secondary cell wall

Eubacteria

5

Domain Archaea

Kingdom Archaebacteria

• Live in extreme and hostile environments

• Has ribosomal proteins similar to eukaryotic cells

• Cell walls lack peptidoglycans

Archaebacteria

7

Methanogens

Break down

cellulose in a cow’s stomach

Produce

marsh

(methane) gas

8

Extreme Halophiles

Live in very

salty water

Use salt to

generate

ATP (energy)

Dead Sea,

Great Salt

Lake inhabitants

9

Thermoacidophiles or

Thermophiles

Live in

extremely hot environments

Found in

volcanic vents, hot springs, cracks on ocean floor that leak acid

10

Clicker Question!

Have a membrane bound nucleus and organelles:

A: Prokaryotes

B: Eukaryotes

C: Nokaryotes

Eubacteria vs

Archaebacteria

Prokaryotic &

Eukaryotic Cells

13

Earliest

Prokaryotes

Most numerous

organisms on

Earth

Include all

bacteria

Earliest fossils

date 2.5 billion years old

14

What domain can be found in harsh environments like: Undersea volcanic vents, acidic hot springs, salty water?

A: Bacteria

B: Archaea

C: Eukarea

15

Clicker Question!

Some eubacteria gain energy from the sun (cyanobacteria), but the rest have to gain energy by consuming other organisms. These are called:

A. Homotrophs

B. Heteroeaters

C. Heterotrophs

D. Homoconsumers

Bacterial Structure

Microscopic

Do not have a nucleus or

membrane-bound organelles

PLASMIDS

Have ribosomes

Single, circular

chromosome

Have plasmids

Unicellular

17

Bacterial Cell

18

Sticky Bacterial Capsule

Prevents drying out, allows it to attach to other surfaces, prevents it from being engulfed, & shelters it from antibiotics

19

Pili in Conjugation

Hairlike structures that help them attach to surfaces and allow for transfer of genetic material between two bacteria

20

21

Flagella

Bacteria that

are motile have appendages called flagella

A bacteria can

have one or many flagella

22

Monotrichous

Amphitrichous

Lophotrichous

Peritrichous

23

Clicker Question!

What structure does this bacterium use for motility?

A: Flagella

B: Cilia

C: Pili

24

Bacterial

Shapes

25

Shapes Used to

Classify

Bacillus:

Coccus:

Spirillum:

26

27

Grouping of Bacteria

Diplo-

Strepto-

Staphylo-

28

29

30

Clicker Question!

What shape and grouping describes the bacteria pointed out below?

A: Staphalacoccus

B: Streptobacillus

C: Diplococcus

31

Staphylococcus

Bacterial

32

Streptococcus Causes

Strep Throat

33

Bacillus - E. coli

34

Streptobacilli

35

Spirillum

36

Leptospira

37

Clicker Question!

1. _________

2. _________

3. _________

4. _________

5. _________

A. Staphylococcus

B. Coccus

C. Spirillum

D. Bacillus

E. Streptococcus

F. Diplococcus

6. _________

38

Gram Staining

Developed in 1884 by

Hans Gram

Bacteria treated with

purple Crystal Violet & red

Safranin stains

Cell walls either stain

purple or pink

39

Gram Positive

Have a thick

layer of peptidoglycan

Stain purple

Can be treated

with antibiotics

40

Gram Negative

Bacteria

Thin layer of peptidoglycan in

cell wall

Outer layer of lipids

Stain pink

Hard to treat with antibiotics

41

Gram Negative

Rickettsiae are

bacteria carried by ticks

Cause Lyme

disease & Rocky

Mountain

Spotted Fever

42

Clicker Question!

Which type of bacteria is susceptible to antibiotics?

A: Gram Positive (Dark Purple)

B: Gram Negative (Light Pink)

2 kinds of reproduction:

• Binary fission

• Conjugation

Cellular organism copies it’s genetic information then splits into two identical daughter cells

45

Binary Fission E. coli

46

Clicker Question!

What kind of reproduction is depicted in the photo below?

A: Asexual

B: Conjugation

C: Binary fission

47

Bacterial Respiration

Anaerobes

Aerobes

48

Modes of Nutrition

Saprobes

– feed on dead organic matter

Parasites

cell

– feed on a host

Photoautotroph

– use sunlight to make food

Chemoautotroph

– oxidize inorganic matter such as iron or sulfur to make food

49

Bacteria and Survival

Bacterial Survival:

Mutations

• Reproduce quickly

• Low rate to fix mistakes in DNA

• Leads to increase in genetic diversity

51

Bacterial Survival:

Endospores

Ecology of Bacteria

All living things need

Nitrogen

Bacteria fix nitrogen to make it usable!

Bacteria decompose and recycle nutrients!

Normal Flora

•Harmless

•Live on, in, and around you

E. coli helps make

Vitamin K used to help clot blood

Useful Bacteria

Some

bacteria can degrade oil

Used to

clean up oil spills

56

Bacteria make food

Yogurt

Cheese

Buttermilk

Pickles

Chocolate

57

Bacteria make Medicine

• Vitamins

• Antibiotics:

–Streptomycin

–Bacitracin

–Tetracycline

–Vancomycin

Pathogens

STD: Syphilis, gonorrhea, Chlamydia

Respiratory: Strep throat, pneumonia, whooping cough, tuberculosis, anthrax

Skin: Acne, boils

Digestive: Gastroenteritis, food poisoning, cholera

Nervous: Botulism, tetanus, bacterial meningitis

Other: Lyme disease, typhoid fever

59

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