The document provides an overview of bacteria, including their structures, types, shapes, reproduction, how they obtain food, and ways to control bacteria. It discusses that bacteria are single-celled organisms that can be harmful or helpful. Blue-green bacteria are notable as they perform photosynthesis to produce their own food.
2. Introduction to Bacteria
2 TYPES OF BACTERIA:
•Bacteria
-Get food from an outside source
•Blue-green Bacteria
-Make their own food
2
3. BACTERIA
Bacteria - small one celled monerans
Bacteria like a warm, dark, and moist
environment
They are found almost everywhere:
-water -air
-soil -food
-skin -inside the body
-on most objects 3
4. 3 Shapes of Bacteria
Bacteria are classified by shape into 3 groups:
Spiral:
spirilla
rod-shaped:
bacilli,
bacillus
Round:
cocci
4
6. 7 Major Structures of a Bacteria Cell
•Capsule
•Cell wall
•Ribosomes
•Nucleoid
•Flagella
•Pilli
•Cytoplasm 6
7. 7 Major Structures of a Bacteria Cell
Capsule
keeps the cell
from drying out
and helps it
stick to food or
other cells
7
8. 7 Major Structures of a Bacteria Cell
Cell wall
Thick outer
covering that
maintains the
overall shape of
the bacterial
cell
8
9. 7 Major Structures of a Bacteria Cell
Ribosomes
cell part where
proteins are made
Ribosomes give
the cytoplasm of
bacteria a granular
appearance in
electron
micrographs 9
10. 7 Major Structures of a Bacteria Cell
Nucleoid
a ring made
up of DNA
10
11. 7 Major Structures of a Bacteria Cell
Flagella
a whip-like
tail that some
bacteria have
for locomotion
11
13. 7 Major Structures of a Bacteria Cell
Pilli
hollow hair-like
structures made
of protein
allows bacteria
to attach to
other cells.
Pilli-singular
Pillus-plural 13
14. 7 Major Structures of a Bacteria Cell
Cytoplasm
clear jelly-like
material that
makes up most
of the cell
14
15. Reproduction of Bacteria
•Binary Fission- the process of one organism
dividing into two organisms
•Fission is a type of asexual reproduction
•Asexual reproduction- reproduction of a
living thing from only one parent
How?...
The one main (circular)
chromosome makes a
copy of itself
Then it divides into two 15
17. Reproduction of Bacteria
•The time of reproduction depends on how
desirable the conditions are
•Bacteria can rapidly reproduce themselves in
warm, dark, and moist conditions
•Some can reproduce every 20 minutes
(one bacteria could be an ancestor to
one million bacteria in six hours)
17
19. Bacteria Survival
Endospore-
•a thick celled structure that forms inside
the cell
•they are the major cause of food poisoning
•allows the bacteria to survive for many years
•they can withstand
boiling, freezing, and
extremely dry conditions
•it encloses all the
nuclear materials
and some cytoplasm 19
21. Bacteria Survival – Food sources
parasites – bacteria that feed on living things
saprophytes – use dead materials for food
(exclusively)
decomposers – get food from breaking down
dead matter into simple chemicals
important- because they send minerals
and other materials back into the soil so
other organisms can use them 21
22. Harmful Bacteria
• some bacteria cause diseases
•Animals can pass diseases to humans
Communicable Disease –
Disease passed from one organism to another
This can happen in several ways:
•Air
•Touching clothing, food, silverware, or toothbrush
•Drinking water that contains bacteria
22
23. Harmful Bacteria
Human tooth with accumulation of bacterial
plaque (smooth areas) and calcified tartar
(rough areas) 23
24. Helpful Bacteria
•Decomposers help recycle nutrients into the
soil for other organisms to grow
•Bacteria grow in the stomach of a cow to
break down grass and hay
•Most are used to make antibiotics
•Some bacteria help make insulin
•Used to make industrial chemicals
24
26. Helpful Bacteria
•Used to treat sewage
Organic waste is consumed by the bacteria,
used as nutrients by the bacteria, and is no
longer present to produce odors, sludge,
pollution, or unsightly mess.
•foods like yogurt, cottage & Swiss cheese,
sour cream, buttermilk are made from
bacteria that grows in milk
26
27. Controlling Bacteria
3 ways to control bacteria:
1) Canning- the process of sealing food in
airtight cans or jars after killing bacteria
•endospores are killed during this process
2) Pasteurization- process of heating milk
to kill harmful bacteria
3) Dehydration- removing water from food
•Bacteria can’t grow when H2O is removed
•example: uncooked noodles & cold cereal
27
28. Controlling Bacteria
Antiseptic vs. Disinfectants
Antiseptic- chemicals that kill
bacteria on living things
•means – “against infection”
Examples: iodine, hydrogen peroxide,
alcohol, soap, mouthwash
Disinfectants- stronger chemicals that
destroy bacteria on objects or nonliving
things
28
29. BLUE-GREEN BACTERIA
Autotrophs – make their own food
through photosynthesis
larger than most bacterial cells
commonly grow on water and surfaces that
stay wet…such as rivers, creeks and dams
Some live in salt water, snow, and acid
water of hot springs
food source for animals that live in the
water 29
30. BLUE-GREEN BACTERIA
can be toxic to humans and animals
Blooms- occur when the
bacteria multiplies in great
numbers and form scum on
the top of the water
30
32. Bacteria Survival
Endospore-
•a thick celled structure that forms inside
the cell
•it encloses all the nuclear materials
and some cytoplasm
•They can withstand boiling, freezing, and
extremely dry conditions
•Allows the bacteria to survive for many years
32
33. Bacteria Survival – Food sources
parasites – bacteria that feed on living things
saprophytes – use dead materials for food
decomposers – get food from breaking down
dead matter into simple chemicals
important- because they send minerals
and other materials back into the soil so
other organisms can use them
33
34. Harmful Bacteria
• some bacteria cause diseases
•Animals can pass diseases to humans
Communicable Disease –
Disease passed from one organism to another
This can happen in several ways:
•Air
•Touching clothing, food, silverware, or toothbrush
•Drinking water that contains bacteria
34
35. Harmful Bacteria
Human tooth with accumulation of bacterial
plaque (smooth areas) and calcified tartar
(rough areas) 35
36. Helpful Bacteria
•Decomposers help recycle nutrients into the
soil for other organisms to grow
•Bacteria grow in the stomach of a cow to
break down grass and hay
•Most are sued to make antibiotics
•Some bacteria help make insulin
•Used to make industrial chemicals
36
39. BLUE-GREEN BACTERIA
Make their own food through
photosynthesis
Bigger than most bacterial cells
Commonly grow on water and surfaces
that stay wet…such as rivers, creeks and
dams
39
40. BLUE-GREEN BACTERIA
It can be toxic to humans and animals
Blooms- occur when the bacteria
multiplies in great numbers and
form scum on the top of the
water
40