2. Quick Quiz True or False
1. 600 different kinds of bacteria live on your skin.
True
2. Saliva contains 30 different kinds of bacteria.
False; 6
3. Most bacteria multiply using the process of binary
fission.
True
4. You can see, taste, and smell bacteria.
False; cannot see with naked eye
5. Leaving foods at room temperature will slow
bacterial growth.
False; Place in cold environments
6. There are more microbes on your body than there
are humans on the entire planet.
True.
3. True / False con’t
7. Bacteria help our bodies with digestion and
produce
True: E. coli makes vitamin K and B12
8. Bacteria are used to make chocolate.
True; it helps digest the hard outer covering
of the bean
9. Only 50% of all bacteria are helpful.
False; 99%
10. The four shapes of bacteria are circular,
square, rod, and spiral.
False; No square
5. Bacteria
Can be found almost everywhere on
Earth.
Earliest known fossils 3.5 bya
Oldest group of organisms
All bacteria are prokaryotes
2 main groups (kingdoms)
Eubacteria
Archaebacteria
6. EUBACTERIA / TRUE BACTERIA
Most common today
Cause disease & decay
Cell wall protects and determines
shape.
Contains peptidoglycan (carbohydrate)
Example:
E. coli= live in intestines of humans
7. Archaebacteria “ancient bacteria”
Live in extreme environments
Direct ancestors of eukaryotes
Examples:
Methanogens= oxygen free
environments thick mud and digestive
tracks.
Halophites= Salty environments Utah’s
Great Salt Lake
8. Prokaryotes are Identified By
their…
1. Shape
2. Chemical Nature
3. The way they move
4. The way they obtain
energy.
12. Cell Walls of Bacteria
Gram staining helps distinguish between the 2
different types of bacteria.
Gram +
Thicker peptidoglycan walls
Keeps dark
stain
Appears purple
Gram –
Thinner
cell wall
Appears pink
13. Gram Staining- Use to diagnose
& treat disease
Gram + Gram –
Harmless Harmful
Important Unaffected by
in
food and many
dairy antibiotics.
Can’t penetrate
industries cell wall
Turns purple Turns pink
Ex)
Ex) E. coli
Streptococcus
pneumonia
14. Movement
1) Flagella- whip
like structures
2) Lash, snake, or
Flagella Position
spiral
3) Glide along
slime
15. Obtaining Energy
Heterotrophs-
Getenergy by consuming organic
molecules made by other organisms.
Autotrophs-
Make their own food from inorganic
molecules.
16. Autotrophs
Photoautotrophs
Use sunlight to convert carbon
dioxide & water to carbon
compounds and oxygen.
Ex: Cyanobacteria
Chemoautrotrophs
Use energy from chemical reactions
to make organic carbon molecules
Live in darkness; ocean bottoms.
17. Releasing Energy
Obligate aerobes- require oxygen
TB Mycobacteruim tuberculosis
Obligate anaerobes- NO oxygen
Clostridium botulinum (canned
food)
Facultative anaerobes- do not require
oxygen but are not killed by it.
E. coli (large intestines and canned
food)
18. Growth & Reproduction
Some bacteria can divide in ~20
min
3 ways bacteria divide
1) binary fission
2) Conjugation
3) Spore formation
19. Bacteria Reproduction
Binary fission
Asexual – clones
Splitting in ½
1st growth
2nd DNA is copied
3rd splits into 2
cells
21. Spore Formation
Formed in unfavorable
conditions
Can keep for months or years
Produces a thick internal wall
that encloses the DNA &
cytoplasm
Dangerous
24. 1) Producers / Nitrogen Fixers
Plants & animals depend on bacteria
for nitrogen
Need N2 to make amino acids.
N2 makes up ~ 80% of Earth’s atm
Plants take N2 convert it to NH3
(ammonia) this process is known as
nitrogen fixation is done by
bacteria.
25. 2) Decomposers
Bacteria recycle nutrients
Trees die -> Bacteria break
down -> Nutrients are returned
to the soil -> Process repeats
26. 3) Human Uses
Food- cheese, yogurt
Beverages- wine, milk
Industry- digest petroleum, clean
up oil spills
Medical uses- synthesize drugs
E. coli- makes vitamins the body
cannot make
Etc.