MIC 1 - EUKARYOTIC CELL.docx

**ALGAE** - Photosynthetic, eukaryotic organism - Classified in the second kingdom **(Protista)** **PHYCOLOGY/ALGOLOGY** -- study of algae **PHYCOLOGIST/ALGOLOGIST** -- person who studies algae **PARTS (UNIQUE)** **PELLICLE** - a thickened cell membrane **STIGMA** - light sensing or...

**ALGAE** - Photosynthetic, eukaryotic organism - Classified in the second kingdom **(Protista)** **PHYCOLOGY/ALGOLOGY** -- study of algae **PHYCOLOGIST/ALGOLOGIST** -- person who studies algae **PARTS (UNIQUE)** **PELLICLE** - a thickened cell membrane **STIGMA** - light sensing organelle, also known as an *eyespot* **CHARACTERISTICS** - range in size from tiny, unicellular, microscopic organisms (e.g., diatoms, dinoflagellates, desmids) to large multicellular, plantlike seaweeds - not all algae are microorganisms - found in freshwater and slat water, in wet soil, and on wet rocks - produce their energy by photosynthesis - few species use organic nutrients, and others survive with very little sunlight - most algal cell wall contains cellulose, a polysaccharide not found in the cell wall of any other microorganism - classified as green, golden (or golden brown), brown, or red **DIATOMS** - tiny - important members of phytoplankton - have silicon dioxide - refracture **DINOFLAGELLATES** - microscopic, unicellular, flagellated, often photosynthetic algae - important members of the phytoplankton, producing much of the oxygen in our atmosphere and serving as important links in food chains - some produce light -- referred to as fire algae - responsible for "red tides" **GREEN ALGAE** **DESMIDS** - unicellular algae - resemble a microscopic banana **SPIROGYA** - filamentous alga - often producing long green strands in pond water **CHLAMYDOMONAS** - unicellular biflagellated alga - containing one chloroplast and a stigma **VOLVOX** - multicellular alga (sometimes referred to as colonial alga or colony - consist 60,000 interconnected, biflagelllated cells, arranged to form a hollow sphere - flagella beat in a coordinated manner - move through the water in a rolling motion **EUGLENA** - possess features possessed by both algae and protozoa - contains chloroplast, is photosynthetic. And stores energy in the form of starch - protozoan features include the presence of a primitive mouth (called a cytostome) and the absence of a cell wall (no cellulose) - Cytostome is for attachment - Possess photo sensing organelle (stigma), flagellum, and pellicle **MEDICAL SIGNIFICANE** **PROTOTHECA** - very rare cause of human infection (causing disease known as protothecosis) - lives in soil and can enter wounds - produce a small subcutaneous lesion that can progress to a crusty, warty looking lesion - if the organism enters the lymphatic system, it may cause a debilitating, sometimes fatal infection - several other genera secrete substances (phycotoxins) that are poisonous to humans, fish, and animal **FUNGI** - (sing., Fungus) are in a kingdom all by themselves - Found almost everyday - **SAPHROPHYTIC FUNGI** -- living on organic matter, in water and soil - **PARASITIC FUNGI** -- living on and within animals and plants - Needs a living host to get nutrients and live - PARASITISIM -- first one benefit but other one is harm - Live on many unlikely materials *HARMFUL FUNGI* - Cause detorioration of leather and plastics - Spoilage of jams, pickles *BENEFICIAL FUNGI* - Cheeses, beer, wine - Certain drugs (immunosuppressant drug cyclosporine - Antibiotics (penicillin) **MYCOLOGY** -- study of fungi **MYCOLOGIST** -- person who studies fungi **GENERAL CHARACTERISTICS** - Diverse group of eukaryotic organisms - Includes yeast, molds, and mushrooms - SAPROPHYTES -- source of food is dead and decaying organic matter - Garbage disposers, vultures - Original recyclers -- by secreting digestive enzymes into dead plant and animals, natter- decompose this material into absorbable nutrients - Produce both asexual and sexual spores - Fungal spores are very resistant structures - Resistant to heat, cold, acids, bases *DIFFER FROM PLANTS AND ALGAE* - Not photosynthetic - No chlorophyll or other photosynthetic pigments - Don't contain algal and plant cells in their cell wall - Contain a polysaccharide called **Chitin** (not found in the cell walls of any other organism) **REPRODUCTION** - Cells can reproduce by budding, hyphal extension, or the formation of spores **TWO GENERAL CATEGORIES** 1\. **SEXUAL SPORES** - Produce by the fusion of two gametes (thus by the fusion of two nuclei) - Have a variety of names (e.g. ascospores, basidiospores, zygospres) **2. ASEXUAL SPORES** - Formed in many different ways but not by fusion - Also called as conidia **CLASSIFICATION** TWO PHYLA "LOWER FUNGI" - **ZYGOMYCOTINA** (OR ZYGOMYCOTA) - Bread moulds - Cause food spoilage - **CHYTRIDIOMYCOTINA** (OR CHYTRIDIMYCOTA) - Not consider to be true fungi - Live in water (water moulds) and soil FIFTH PHYLUM - **DEUTEROMYCOTINA** (OR DEUTEROMYCOTA) - No mode of sexual reproduction - Fungi imperfecti - *Aspergillus and Penicillium* - **DEUTEROMYCETES** -- where antibiotic came from **YEAST** - Eukaryotic single cell (unicellular) that lacks mycelia - BLASTOSPORES/BLASTOCONIDIA -- individual yeast cell that can only be observed using microscope - Found in soil and water and on the skins of many fruits and vegetables - Yeast on skin of grapes were responsible for fermentation process - Common yeast "Saccharomyces cerevisiae" (baker's yeast) - Good source of nutrients for humans because they produce many vitamins and proteins - Some yeast (*Candida albicans and Cryptococcus neoformans*) are human pathogen - C. albicans is most frequently isolated from human clinical specimens **MOULDS** - Grow in the form of cytoplasmic filaments or hyphae - Reproduction is by spore formation, either sexually or asexually - Have great commercial importance - For example, within the Ascomycotina and the Basidiomycotina classes are found many antibiotic-producing moulds, such as Penicillium and Cephalosporium - Produce large quantities of enzymes - Amylase, which converts starch to glucose, citric acid, **DIMORPHIC FUNGI** - Few fungi, can live either yeast or as moulds depending on growth condition - *Phenomenon* is called dimorphism, and the organisms referred to as dimorphic fungi **FLESHY FUNGI** - Large fungi that are encountered in forest - Mushrooms, toadstools - Not microorganism - Mushroom -- class of true fungi that consist of a network of filament or strands (mycelium) that grow in a soil or in a rotting log **LICHENS** - Appear as colored, often circular patches on tree trunks and rocks - **ALGA (cyanobacterium)** -- combination of two organisms - **FUNGUS** -- living together in such a close relationship that they appear to be one organism - Not associated with human disease - Some substances produce may have antibacterial properties **SLIME MOULDS** - Found in soil and rotting logs - Have both fungal and protozoal characteristics - Some start as independent amebae, ingesting bacteria and fungi by phagoytosis - Not known to cause human disease **MEDICAL SIGNIFICANCE** - They cause disease - Many diseases of crop plants, grains, corn and potatoes are caused by moulds - Produce toxins (mycotoxins) - **MYCOSES** -- moulds and yeast cause variety of infection disease to animal and human - Very few are pathogenic to human **ALGAE** - Eukaryotic organism - Classified in the second kingdom (PROTISTA) PROTOZOOLOGY -- study of protozoa PROTOZOOLOGIST -- person studies protozoa **CHARACTERISTICS** - Unicellular - Fee-living organisms, found in soil and water - More animal-like - Do not have cell walls but some have flagellates and some ciliates - Possess pellicle -- serve as protection - Ingest foo through primitive mouth or opening called **cytostome** - **CONTRACTILE VACUOLE** -- pumps water out of cell - *Vorticella spp*. (pond water ciliates) have a contractile stalk, within the stalk is a primitive muscle fiber called **myoneme** - Some are parasites - **PARASITES** -- break down and absorb nutrients from the body of host - Many parasitic protozoa are pathogen - MUTUALISTIC SYMBIOTIC RELATIONSHIP -- a relationship in which both organism benefit - Ex. Termite and its intestinal protozoa **PROTOZOAN LIFE CYCLE** 1\. TROPHOZOITE - Motile, feeding, dividing stage 2\. CYST - Nonmotile, dormant, survival stage **AMEBAE (AMEBAS)** - Move by means of cytoplasmic extensions called **PSEUDOPODIA** (pseudopodium; false feet) - **AMEBOID MOVEMENT** -- process in which an ameba first extends to pseudopodium in the direction intents to move and then rest of the cell slowly flows into it - Ingest a food particle by the process of phagocytosis - One medically important is - *Entamoeba histolytica* - Causes amebic dysentery (amebiasis) - Extraintestinal amebic abscesses **CILIATES** - Move about by means of large numbers of hair-like cilio on their surfaces - Oarlike motion - Complex of all protozoa - Pathogenic ciliate - *Balantidum coli --* transmitted to human by drinking water that has been contaminated by swine feces - Only ciliated protozoan that causes disease to human **FLAGELLATED PROTOZOA** - Move by means of whiplike flagella - **KINETOSOME/KINETOPLAST** -- anchors each flagellum within cytoplasm - Exhibit wavelike motion - Some are pathogenic - *Trichomonas vaginalis* -- causes STD (trichomoniasis) - *Giardia lamblia* -- causes persistent diarrheal disease **NON-MOTILE PROTOZOA** - Lacking pseudopodia, flagella, or cilia - Classified in a category of SPOROZOA - Most important pathogen - *Plasmodium spp. --* causes malaria - *Toxoplasmosis --* cause toxoplasmosis - *Plasmodium vivax --* few cases of malaria - Malaria parasites is transmitted by female ANOPHELES mosquitos - Become infected when they ate blood meal from a person with malaria