Transcript Bacteria - Conackamack Middle School

Virus Review!
1.What are the two main parts that make up
the structure of a virus?
2.What is the difference between an active and
a hidden virus?
3.What is the term used to describe the
chemical that prevents viruses? How does it
actually work?
4.The influenza of 1918 is known as, “one of
the worst pandemics the world has ever
known.” What do think a pandemic is?
Bacteria
Pages 217-225
Two Domains/
Two Kingdoms
DOMAINS: 1. Archaea 2. Bacteria 3. Eukarya
• KINGDOM
• KINGDOM
Archaebacteria
Eubacteria
– Live in extreme
enviroments
• Water as hot as 110°C
• Acidic as lemon juice
• Intestines, mud, and
sewage
– Produce foul odors
– DO NOT live in
extreme enviroments
– Live everywhere else
• Coat your skin
• Swarm in your nose
– Most are either useful
or harmless to you
Bacteria
• HISTORY: Anton van
Leeuwenhoek found
bacteria first in teeth
scrapings
• STRUCTURE:
single celled
prokaryotes
– DNA floats in cytoplasm
(no nucleus)
– Ribosomes; no other
organelles
Three cell shapes
• Rodlike
(Phylum Bacilli)
• Spherical
(Phylum Cocci)
• Spiral Shaped
(Phylum Spirilli)
Phylum Cocci
Streptococcus aureus
Causes Strep Throat
Staphylococcus aureus
Causes staph infections
Neisseria gonorrhoeae
Causes a sexually transmitted
disease called gonorrhea
Phylum Bacilli
Escherechi coli
Causes food poisoning
Bacillus anthracis
Causes anthrax, can grow in aerobic
OR anaerobic environments
Bacillus thuringiensis
A bacterium found in soil that
keeps away insects.
Phylum Spirilla
Borrelia burgdorferi
Found in intestines of ticks,
carries Lyme disease
Treponema pallidum
Causes the sexually transmitted
disease, syphilis.
Spirillum minus
found in rodents
causes rat bite fever
in those people who
come in contact with
infected rats
How do Bacterial Cells Move?
• Flagellum – a long
whip-like structure that
moves the cell like a
propeller.
• May also have tiny
protein fibers called pili.
• Most bacteria without
flagellum cannot move
on their own and must
rely on other things to
move them.
Two Types of Reproduction
• Sexual Reproduction – involves two parents who
combine their genetic material to produce a new
organism, which differs from both parents.
– Conjugation – one bacterium transfers some of its
genetic material to another bacterium through a thin,
threadlike bridge that joins the two cells
– The term sexual reproduction is loosely used here.
There is an exchange of DNA, however no NEW cells
are created.
A pilus bridges
from one cell to
the other
Two Types of Reproduction
• Asexual Reproduction – reproductive process that
only involves one parent and produces offspring
that are
– Binary Fission – process by which one cell divides to
form two identical cells. A form of asexual reproduction.
identical to the parent.
Stages of Bacterial Growth
• LAG PHASE: Growth is slow at
first, while the microbes acclimate
to the food and nutrients in their
new habitat.
• LOG PHASE: Once used to the
environment, they start multiplying
exponentially, doubling in number
every few minutes.
• STATIONARY PHASE: As more
and more microbes are competing
for dwindling food and nutrients,
booming growth stops and the
number of bacteria stabilizes.
• DEATH PHASE: Toxic waste
products build up, food is depleted
and the microbes begin to die.
Lag
• Some bacteria are
autotrophic and make their
own food.
– They can use the sun’s
energy the same way plants
do (photosynthesis), or they
can use chemical substances
in their environment to make
food (chemosynthesis).
• Other bacteria are
heterotrophic. They get their
food by eating autotrophs or
other heterotrophs.
Getting
Food
Respiration
• Like many other organisms most bacteria
need oxygen to break down their food to
get energy. (AEROBES)
• A few kinds of bacteria do not need
oxygen, and it is actually like poison to
them. (ANAEROBES)
An anaerobic bacteria
found in soil
Is All Bacteria Bad?
• Bacteria is not all bad. There are several ways
in which Bacteria is helpful.
1. Involved in fuel and food production
2. Environmental recycling and cleanup.
3. Decomposers - break down large chemicals in dead
organisms into small chemicals
Illness and Health
• Some bacteria can make you sick.
Bacterial diseases can be passed in many ways.
– Direct contact, like touching, hugging, or kissing.
– Indirect contact, such as inhaling drops of moisture, or
sharing food and drink.
– Who has a cell phone?
Treatment?
• Bacterial diseases are treated with antibiotics,
such as penicillin, and amoxicillin.
– A chemical that can kill bacteria without harming a
person’s own cells.
• You also have bacteria in you digestive system
to help break down food.
Bacteria Review