Download Helpful and Harmful Microorganisms

HARMFUL AND BENEFICIAL
MICROORGANISMS
HELPFUL AND HARMFUL
MICROORGANISMS
A
microorganism is
a living thing that is
too small to see
without a microscope.
These include:
 Amoebas
 Algae
 Bacteria
 Viruses
 Protists
 Fungi
 Other tiny
organisms
BACTERIA ARE ONE-CELLED ORGANISMS.
BACTERIA
Bacteria are onecelled organisms.
 They can only be seen
using a microscope.
 There are more
bacteria than any
other living thing.
 Bacteria are the
oldest form of life on
Earth.

Bacteria have no
nucleus.
 The cytoplasm of
bacteria carries the
material that would
be in the nucleus of
other cells.
 There are both helpful
and harmful types of
bacteria.

HOW DOES BACTERIA GROW?
Imagine a colony of 10 bacteria that doubles
every 20 minutes.
 Let’s do the Math! Calculate how many bacteria
will be in the colony after two hours.
 Create a graph with your results.
 Based on this information, guess how long it
would take for the colony to surpass one million
organisms.
 Turn and talk about your guesses!

HOW ARE MICROORGANISMS BENEFICIAL
TO HUMANS?
Digestion-
FoodFood like cheese, pickles, olives, sausages,
chocolate, bread, wine, beer and soy sauce
are all made with the help of different types
of bacteria and yeast. In most of these food
products, bacteria play a major role because
they produce lactic acid.
Certain types of bacteria live in the
intestines of human beings. They help in
digestion and in destroying the harmful
organisms. Intestinal bacteria also produce
some vitamins required by the human body.
Certain bacteria helps break down lactose in
the digestive tract. Healthy stomach bacteria
are releases many useful vitamins such as
vitamin B and vitamin K, etc.
Microorganisms
Decompositionbacteria, fungi, moulds, protozoa and other
organisms feed upon decaying organic
materials. In the later stages of
decomposition, mites, millipedes, centipedes,
springtails, beetles and earthworms further
break down and enrich these composting
materials.
MedicineOne of the most important groups of
medicines, antibiotics, is produced by
fungi and bacteria. Most antibiotics
used today were found originally in
fungi. Fungi get their nourishment
from dead animals or plant matter.
ALGAE
BENEFICIAL MICROORGANISM, KNOWN AS A
PRIMARY PRODUCER, IMPORTANT TO FOOD
CHAIN.
Yeast
Beneficial one celled organism,
helps bread to rise. Yeast is rich in
protein, mineral, carbohydrates and
vitamin B.
HELPFUL MICROORGANISMS
You might be surprised to find that we could not
live without microorganisms.
 Without algae and other tiny plants floating in
the ocean, we would not have enough oxygen to
stay alive!
 Plankton is another tiny organism that floats on
the surface of the ocean, providing food for the
ocean food chain.

HELPFUL OCEANIC MICROORGANISMS
Algae
Plankton
BACTERIA
SMALL ORGANISMS THAT CAN BE FOUND IN ALL NATURAL
ENVIRONMENTS. THEY ARE HELPFUL AND HARMFUL.
BACTERIA IS USED IN FUEL PRODUCTION, FOOD (YOGURT,
CHEESE, SOUR CREAM) AND MEDICINES.
Plankton
Very important to life on
earth and in bodies of
water. Major source of food.
HELPFUL LAND MICROORGANISMS
Certain fungi help plants take up nutrients from
the soil.
 Microorganisms help provide us with other kinds
of foods.
 Bacteria turn milk into yogurt.
 Bacteria also helps produce certain kinds of
cheese.
 Yeast makes bread, rolls, and cake rise.

 Without
microorganisms, we would have
trouble eating any food. Certain bacteria in our
bodies help digest our food.
 Without microorganisms, we would also have
fewer medicines. Penicillin is made from a
mold. Streptomycin is made from bacteria.
Both help treat or cure many diseases.
 Some microorganisms help remove harmful
wastes from sewage at water treatment plants.
 Others help clean up oil spills.
 Microorganisms make dead things decay.
Without them, Earth would be covered in a
very thick layer of dead plants and animals!
HARMFUL MICROORGANISMS
Some
harmful
bacteria can
make you
very sick.
They are
found on raw
meat, raw
eggs, and
other foods.
Salmonella
E. Coli
The strep
bacteria can
cause strep
throat. It can
lead to
serious
illness in the
young, old,
or those
already sick.
Staph
Staph
bacteria is
on our skin
all the time.
It can cause
pimples or
infections.
Strep
A virus is
another
microorganism
that causes
disease. It is
even smaller
than bacteria.
.Flu Virus
Cold Virus
A virus must
use living
cells to grow
and
reproduce.
Viruses often
change as they
reproduce.
A medicine
that killed the
first virus often
cannot kill the
changed virus.
DID YOU WASH YOUR HANDS TODAY WITH
SOAP AND WATER?
WHY ARE SOME MICROORGANISMS
HARMFUL?

Food poisoning: Food contains bacteria. If food is not stored at the proper
temperature then the bacteria multiplies very rapidly. If this food is eaten it can
cause nausea, vomiting, diarrhea, or in serious cases, death. Food poisoning can also
be caused by eating food that is not cooked properly, like chicken or eggs. When food
is cooked, harmful bacteria is killed (bacteria is not the only cause of food poisoning).
E. Coli, Salmonella are more well known bacteria in food.
Prevention: Cook food thoroughly, especially meats. Refrigerate foods..

Bacterial Infections: includes strep throat, ear infections, pneumonia, and
bronchitis. These are different from viruses. If treated properly, they are not life
threatening, but if not treated can spread to other organs in the body.
Solution: Antibiotics

Acne: caused in part by infection of bacteria in pores.
Prevention: do not touch face and spread bacteria to face; wash face
Cavities: caused by bacteria that eat sugar and convert it into acid plaque eats at
tooth enamel.
Solution: brushing teeth and flossing
 Body Odor: when we sweat, bacteria begins to multiply rapidly n the warm, moist
skin. The bacteria quickly multiply, then dies, releasing an odor as they decompose
or rot.
Prevention: washing daily and wearing deodorant.

SALMONELLA
CAN ENTER THE HUMAN SYSTEM THROUGH
CONTAMINATED WATER, MEET OR EGGS
WITH CRACKED SHELLS. IT IS DIFFICULT TO DETECT
BECAUSE IT GIVES NO OBVIOUS WARNINGS.
E. Coli
Normally inhabit the intestine of
humans and animals. E. Coli is both
helpful and harmful. It can compromise
the immune system but also gives us a source of
vitamins B12 and K.
STREPTOCOCCAL
INFECTION
OF THE MUCUS
MEMBRANE LINING IN THE
PHARYNX.
MOST COMMON IN SCHOOL AGED
CHILDREN, PASSED FROM PERSON TO PERSON.
FUNGUS
(PLURAL: FUNGI)
Like plants,
fungi cannot
move
around.
Like animals,
fungi cannot
make their
own food.
Mold is a type
of fungi.
Each bit of
mold is very
small, but
when it grows
in large groups,
you can see it.
Yeast is a onecelled fungi.
Harmful
mold and
other fungi
can spread
through
crops and kill
them.
Fungi get
their energy
by eating
other living
or dead
organisms.
Mold
Mushrooms
are multicelled fungi.
Fungi can
cause skin
diseases such
as athlete’s
foot and
ringworm
(which is not
really a
worm).
Harmful
mold and
fungi can
also rot
wood and
food.
Rotten Wood
Ringworm
Athlete’s
Foot
OUR SURVIVAL ACTUALLY DEPENDS ON THE
HELPFUL MICROORGANISMS IN AND AROUND
US!
TURN AND TALK, THEN WRITE DOWN YOUR
ANSWERS IN YOUR SCIENCE JOURNAL.
Discussion Question:
 Why do many people
think that all
microorganisms are
harmful?

Discussion Question:
 Do you think that the
world is better of with
or with out bacteria?
Why?

LET’S TAKE A POLL!
We will conduct a poll to determine if people
consider bacteria helpful or harmful.
 You will tally the results and make graphs for
the subgroups polled such as: first grade
students, second grade, third and fourth grade
students.
 We will then share our results. If most students
consider bacteria is harmful you will create a
poster sharing the beneficial effects of bacteria.
If most students believe bacteria is beneficial you
will create a poster showing the harmful effects
of bacteria.

WHAT IS THE ROLE OF ANTI-BACTERIAL
AGENTS THAT PROMOTE HEALTH AND WELL
BEING?
Why should I use hand sanitizer isn’t it the same
as soap?
 Let’s experiment!
 Compare the images on the next slide.
 Turn and talk to your partner!
 Which would you use regular soap or sanitizer?

SANITIZER
TOP DAY- 1
BOTTOM DAY- 5
SOAP
TOP- DAY 1
BOTTOM- DAY 5
WHAT IS THE ROLE OF ANTI-BACTERIAL
AGENTS THAT PROMOTE HEALTH AND WELL
BEING?
Though soap and warm water may be more
effective, in the world of kid play, where, when
asked to clean their hands, most kids do it
quickly, in cold water.
 Antibacterial hand lotion is a great, and more
effective alternative to soap and water.
 Antibacterial hand lotion promotes good hygiene
and protects your body against SOME bad
bacteria, Not All Bacteria.

FOR MORE INFORMATION

www.amnh.org/explore/infection/index.html
“Infection Detection Protection” is a Web site hosted by the American
Museum of Natural History that contains a great deal of information about
microbes and their effect on our lives. Several interactive games that teach about
bacteria are also included.

www.microbe.org/microbes/bacterium1.asp
The American Society for Microbiology hosts “Stalking the Mysterious
Microbe,” a site for elementary students interested in learning more
about microorganisms including bacteria.