MicroorganismsUNIT THREE, LESSON 3.6BY MARGIELENE D. JUDAN

LESSON OUTLINE Activity IntroductionFungiProtozoansBacteriaViruses

Through the help of microscopes, biology became a complex science. It enabled us to cure more diseases and explore life at a detailed level. Many things that cannot be seen by the naked eye have been discovered: cells, tissues, and microorganisms.

Turn to p.112. We will compare the microorganisms in a stagnant water, moist stale bread, and hay infusion under a microscope. Get your notebook. Draw the organisms that you will see in each setup.

Microorganisms in stagnant water

Microorganisms in moist stale bread

Microorganisms in hay infusion

Compare and contrast the organisms in each setup. Write them also on your notebook. (9 pts)*Drawing = 2 pts each (6pts)

Total = 15 pts

All the specimens you encountered in the activity are microorganisms.

Microorganisms in stagnant water

euglena oscillatoria

anabaenaamoeba (rarely seen)

Microorganisms in moist stale bread

Bread mold or Rhizopus

Microorganisms in hay infusion

Paramecium

Did you know that microorganisms are the most diverse organisms on the planet?

The group, led by microbiologist William B. Whitman, estimates the number to be five million trillion trillion that's a five with 30 zeroes after it. 

5,000,000,000,000,000,000,000,000,000,000 bacteria! And that doesn’t include other microorganisms like the viruses, fungi and protists!

If each bacterium were a penny (coin), the stack would reach a trillion light years. That’s a way farther than the farthest galaxy discovered, which is just 13.3 billion light years away.

Microorganisms are present everywhere on earth. They can thrive in harsh environments including lava pits, acidic environments and the arctic.

Types of Microorganisms1. Fungi2. Protozoans3. Bacteria4. Viruses

FUNGIPlant-like organisms (but have no chlorophyll)Some act as decomposers (ex. Mushrooms, yeast, mold, penicillium)

FUNGITwo species of fungi: 1. Penicillium notatum – source of antibiotic Penicillin2. Aspergillus flavus – source of aspergillic acid

FUNGISome are beneficial (ex. yeast)Some are harmful (ex. Pathogenic fungi like Tinea capitis, they cause fungal infections like buni, athlete’s foot, etc.)

PROTOZOANSUnicellular (single celled) and eukaryotic (have nucleus)Vary in shape and locomotive structure: flagella, cilia, or pseudopodia* (*pseudo=false, podia=feet; false feet)

Different forms of an amoeba

PROTOZOANSSome species are parasitic; you get infected usually by eating/drinking See the video (next slide) of an amoeba eating two paramecia (also a protozoan)

PROTOZOANSSome examples:1. Amoeba – irregularly-

shaped; some parasitic; moves by pseudopodia

2. Trypanosoma – moves by flagella (tail); can cause sleeping sickness via tsetse fly.

amoeba

Notice the resemblance of a trypanosome to an eel

PROTOZOANSSome examples:3. Trichonympha – moves by

flagella; lives inside termites (they help digest wood)

4. Plasmodium – nonmotile (doesn’t move); all species parasitic; can cause malaria via the mosquito Anopheles

Trichonympha (termite guts)

Plasmodium

BACTERIASmallest among the microorganisms; smallest living cells; simpler cell structure Prokaryotic (no nucleus)Most bacteria are harmless (though we often think of them as the cause of a disease)

BACTERIAImportant for life; they help in various environmental process (ex. Decomposition, nitrogen cycle, oxygen cycle, carbon cycle, etc. by converting substances to usable forms)They help in a process called decay. They break (eat) organic products and recycle them.

BACTERIAGerm Theory of Disease (by Louis Pasteur)Bacteria can cause disease by:1. Becoming so numerous that

they *interfere w/ the normal functioning of the body

2. Some produce toxins or poisons that *.

BACTERIATypes of Bacteria (3 Major Groups)1. Coccus – spherical 2. Bacillus – rod-shaped3. Spirillum – spiral

VIRUSESMarginal organisms (they are not living things because they lack some characteristics of living things)They always rely on a host to reproduce (become living).Virus + host = livingVirus alone = nonliving

VIRUSESWhen not attached into a host, they exist as a protein coat or capsid with DNA or RNA inside. In some cases, they are covered with spikes.They are pathogenic (capable of causing disease; ex. measles, chicken pox, small pox, mumps, rabies, and warts)

Picture Quiz tomorrow (15 items):

Know the appearance of the following by looking at their pictures and drawings (in your notebook)Fungi1. Mold/Rhizopus2. Yeast

Protozoans1. Amoeba2. Trypanosoma3. Trichonympha4. Plasmodium5. Paramecium6. Euglena7. Oscillatoria

8. AnabaenaBacteria (Structure)1. Coccus2. Bacillus3. SprillumVirus

Assignment 1:Answer p. 119 (Check Your Knowledge)

Assignment 2: Differentiate the microorganisms in terms of:a) Cell Structureb) Nucleus (prokaryotic or eukaryotic)c) Function and Activities

Write your answers in a whole sheet of paper. To be passed two days after.

Sources:Science Links 7http://www.sdearthtimes.com/et0998/et0998s8.htmlhttp://www.sciencedaily.com/terms/protozoa.htmhttp://www.differencebetween.info/difference-between-bacteria-and-protozoahttp://www.microbiologyonline.org.uk/about-microbiology/introducing-microbes/bacteria