Microorganisms2012Mrs. Erickson

Science Benchmark

Microorganisms are those living things that are visible as individual organisms only with the aid of magnification. Microorganisms are components of every ecosystem on Earth. Microorganisms range in complexity from single to multicellular organisms. Most microorganisms do not cause disease and many are beneficial. Microorganisms require food, water, air, ways to dispose of waste, and an environment in which they can live. Investigation of microorganisms is accomplished by observing organisms using direct observation with the aid of magnification, observation of colonies of these organisms and their waste, and observation of microorganisms’ effects on an environment and other organisms.

New words…• Language science students

should use: • Algae• Antibiotic• Fungi• Microorganism• Decomposer• Single–celled organism• Bacteria• Host• Infectious disease• virus

• Protozoan• Producer• Parasite• Spore• Vaccine• Hypothesis• Experiment• Investigation• Variable• Control• Culture

Core-Standard 5Students will understand that microorganisms range from simple to complex, are found almost everywhere, and are both helpful and harmful. • Objective 1

Observe and summarize information about microorganisms.

• Examine and illustrate size, shape, and structure of organisms found in an environment such as pond water.

• Compare characteristics common in observed organisms (e.g., color, movement, appendages, shape) and infer their function (e.g., green color found in organisms that are producers, appendages help movement).

• Research and report on a microorganism's requirements (i.e., food, water, air, waste disposal, temperature of environment, reproduction).

Core (cont.)• Objective 2

Demonstrate the skills needed to plan and conduct an experiment to determine a microorganism's requirements in a specific environment.

• Formulate a question about microorganisms that can be answered with a student experiment.

• Develop a hypothesis for a question about microorganisms based on observations and prior knowledge.

• Plan and carry out an investigation on microorganisms.

• Display results in an appropriate format (e.g., graphs, tables, diagrams).

• Prepare a written summary or conclusion to describe the results in terms of the hypothesis for the investigation on microorganisms.

Core (cont. #2)• Objective 3

Identify positive and negative effects of microorganisms and how science has developed positive uses for some microorganisms and overcome the negative effects of others.

• Describe in writing how microorganisms serve as decomposers in the environment.

• Identify how microorganisms are used as food or in the production of food (e.g., yeast helps bread rise, fungi flavor cheese, algae are used in ice cream, bacteria are used to make cheese and yogurt).

• Identify helpful uses of microorganisms (e.g., clean up oil spills, purify water, digest food in digestive tract, antibiotics) and the role of science in the development of understanding that led to positive uses (i.e., Pasteur established the existence, growth, and control of bacteria; Fleming isolated and developed penicillin).

• Relate several diseases caused by microorganisms to the organism causing the disease (e.g., athlete's foot -fungi, streptococcus throat -bacteria, giardia -protozoa).

• Observe and report on microorganisms' harmful effects on food (e.g., causes fruits and vegetables to rot, destroys food bearing plants, makes milk sour).

Microorganisms

• …those living things that are visible as individual organisms only with the aid of magnification.•We use microscopes to see

microorganisms.• …need food, water, air, ways to dispose of

waste, and an environment in which they can live.

Types of Microorganisms

1. Algae2. Archaea3. Bacteria4. Fungus 5. Mold6. Prion7. Protozoan8. Viroid9. Virus10. YeastWe will focus on the ones in bold.

Viruses

• This is a microscopic organism that invades the cell(s) of other living things.• Virus are non-living.• Viruses are different from bacteria because they

cannot make more of themselves without a healthy cell.• They invade other cells and reproduce inside

that cell. That cell is called a host.

Viruses 2

• A parasite is an organism that lives in or on a host and causes harm to that host.• Almost all viruses act like parasites.• Some viruses in humans are: HIV, chicken

pox, colds, cold sores, hepatitis, influenza, measles, mumps, rabies, yellow fever.• There is NO cure for viruses.

Viruses (3)

Naming Viruses• They are named after:•Diseases which they cause.•Organisms they infect.•Places they are found.• Scientist(s) that discover them.

Viruses (4)

Virus Structure• All viruses have two basic parts—an outer

coat that protects the virus & an inner core made of basic genetic material.• Outer coat is made of proteins. It is like

the chocolate on the outside of a candy.• Inner core is the like the gooey filling

inside the candy.

Virus Structure-pictures

Virus structure-drawings

Virus invading host

Still invading…

Bacteria

• These are single-celled life forms.• They come in many different shapes.•Many bacteria are helpful to humans. •One bacteria is a called a bacterium.•Good (helpful) bacteria are called

“probiotics.”

Helpful Bacteria in Foods

•Bacteria are good for making:• Dairy products like cheese, buttermilk,

and yogurt• Sour dough• Vinegar• Soy sauce • “Pickled” foods like olives and pickles

Bacteria can eat…

• Anything humans eat, plus:• Wood• Paper• Glue• Tar• There are even bacteria eating the hull of the Titanic

and within a short time it will be gone.• Bacteria turn dead plants and animals into humus.• Humus is dark rich topsoil we need for growing plants.• Bacteria is helpful in composting.

Decomposers

• Bacteria and other microorganisms that help things to decompose, break down, or “rot.”• Necessary to life.• Biodegradable means that the object is

something that can be decomposed by bacteria or another microorganism.• Sewage treatment plants purify water though

the use of bacteria so it is drinkable.

Bacteria are found…

•We find most of them in the soil.• They can also be found in the air, water,

dry surfaces, and your body.• Although many bacteria are helpful, some

are harmful.

Shapes of Bacteria• Three basic:1. cocci: round (spherical) shaped2. bacilli: rod shaped3. spirilla: spiral shapedThe shape of the bacteria is determined by the chemical makeup of the cell wall.

Shapes of Bacteria (2)

A few others:

1. vibrios: shaped like end rods2. diplo: paired3. staphylo: clustured4. strepto: linked in chains

Bacteria Structure

• Genetic material (center but not in nucleus)• Cytoplasm (around genetic material, gel-

like)• Ribosome (in cytoplasm, create protein)• Cell wall (protective wall)• Flagellum (whip-like, used as propeller of

cell; not all cells have flagella)

Bacteria Structure (2)• Please label the hereditary material, cytoplasm, and cell wall.

What bacteria need to live…

• Certain temperatures• Moisture• Respiration (breathing)• Aerobic (need oxygen to live)• Anaerobic (can live without oxygen)

• Food

Endospores

• Some bacteria form endospores when they dry out• These are thick-walled structures that form

around the bacteria’s hereditary material and some cytoplasm protect it.• When conditions improve, they will come back

to life.

Bacteria Reproduction

• Bacteria have the ability to make more of themselves.• This process is called fission.• One bacteria can split into two. Two can split in

to four, etc.• They can keep making more of the themselves as

long as they have moisture, right temperature, and food.

Bacteria Division• 1 then 2 then 4 then 8…

• http://www.youtube.com/watch?v=o2Njd7eJ3O0&feature=related&safety_mode=true&persist_safety_mode=1&safe=active (12 seconds)

• http://www.youtube.com/watch?NR=1&feature=endscreen&v=HqOg78T5cic&safety_mode=true&persist_safety_mode=1&safe=active (1.41 minutes)

Examples of Bacterial Illnesses• Bubonic Plague• Cholera• Pertussis• Typhoid Fever• Diphtheria• Pneumonia• Tetanus• Strep Throat(Think about what you can take medicine for—like strep—and get better—caused by bacteria—vs. what you just have to get better on your own from—like a cold—cause by a virus.)

Germs

•Germs are bad microorganisms that can make you sick.

Bubonic Plague

• In Europe between 1347-1351 AD.• About 25 million people died.• Nobody knew what caused it. They didn’t not

microorganisms existed.• Was spread by animals.• Some fleas had the bacteria Pasteurella Pestis.• Fleas lived on rats and passed on the bacteria.• Rats lived with humans in many areas & infected them.• Rats would get sick and die.• Fleas would look for another rat to live on. They also

lived on humans.

Anthony Van Leeuwenhoek (pronounced laven hawk)• Lived 300 years ago• Used a powerful

lens like a microscope to discover “wee beasties.” (bacteria)• Hand crafted the

first microscope

Microscope

Louis Pasteur• Proved many

diseases are caused by bacteria.• Invented vaccination

and Pasteurization.

Vaccination • The process (usually by an injection or shot) of putting

weakened bacteria of that disease into a person or animal.• This helps the body to create antibodies for a particular virus.

Sir Alexander Fleming• Discovered the germ-

killing power of green mold Penicillium Notatum.• We have antibiotics

because of him.

Penicillin• This is a powerful antibiotic made from a mold used to treat

infections caused by bacteria.• It prevents formation of the bacteria cell wall.• It will NOT kill viruses.

Immune System• Helps defend the body against bacteria, viruses, and other

harmful invaders.

Protists• Are one-celled organisms with nuclei and organelles.• Bacteria don’t have nuclei and organelles.• Plant and animal cells do have organelles and nuclei.

• Protists move in three ways.1. Flagellum

• A long tail-like thing that whips around causing the cell to move

2. Cilia• Tiny hairs all over the cell that it uses to get around

3. Pseudopod• A structure that allows a protist to “jet” in and out of their cytoplasm

and move around.

Protists (2)• Plant-like protists contain the green pigment chlorophyll.

• http://www.labartlibrary.com/symbiosis/botanyindex.html• http://www.labartlibrary.com/symbiosis/cellsmain2.html• http://lensonleeuwenhoek.net/microscopes.htm