Kingdom Protista

Kingdom Protista Quiz: Tues. 12/6 over microscopes and protists Test: Tues. 12/13 over microscopes, protists, transport, respiration, photosynthesis

Classification of Protists • Kingdom with the most diverse members • Unicellular and multicellular • Heterotrophs, autotrophs, or both • Various types of cell walls Are all Eukaryotes!! (nucleus!)

Classify by how they obtain nutrition So…how do we classify them?? • Animal Like—Heterotrophs • Plant Like—Autotrophs • Fungus Like—Decomposer, Parasites Amoeba This classification system does not explain evolutionary relationships and will probably change in the future.

Also classified by how they move • Some use pseudopods (false feet) • Some use flagella (like a whip) • Some use cilia (tiny hair like structures) • Some don’t move at all This classification system does not explain evolutionary relationships and will probably change in the future.

Amoeba Movement Video Animal-Like Protists • Amoeba and Entamoeba • Pseudopods are temporary projections of cytoplasm (false feet)

Animal-Like Protists • Flagellates: • Have flagella-whip like structure that aid in movement • EX: Triconympha—lives in the gut of termites and helps digest wood • Trypanosomas—African sleeping sickness caused by bite of a Tsetse fly

Animal-Like Protists • Ciliates: Move with cilia • Hair-like projections used for moving and catching food • EX: Paramecium Contractile Vacuole—used to pump out excess water from the cell Gullet for food intake

Animal-Like Protists • Phylum Sporozoans—parasitic protists • Nonmotile—do not move • EX: Plasmodium—causes Malaria, carried by Anopheles mosquito

http://www.youtube.com/watch?v=8GPn9rqg_HA

Ecology of Animal-Like Protists • Why are they important?? • Live symbiotically with other organism (termites gut) • Live in lakes/oceans, bottom of marine food chain (zooplankton) • Recycle nutrients/make organic matter

Plant-Like Protists—Algae • Unicellular and multicellular • Autotrophs • Produce most of the worlds oxygen • Use chlorophyll and accessory pigments to collect light

Unicellular Algae—Diatoms • Glass-like cell walls made of silica • Forms diatomaceous soil when they die and sink to the ocean floor. • Uses: • Filter ponds • Abrasive in cleaners • Brightener in paints • Kills pests (slices exoskeleton)

Diatoms

Unicellular Algae—Euglena • Has 2 flagella • Contractile vacuole—pumps out excess water to maintain homeostasis • Pellicle—Cell wall • Eye spots—detect light • Both heterotrophic and autotrophic (plant and animal like)

Euglena

Multicellular Algae Pond scum Volvox: colonial algae Red Algae-used to make agar Brown Algae: Sea Kelp

Diseases… • Giardia - causes humans to become sick when drink water with cyst • Gonyaulax - produces toxins that paralyze and kill (red tide) • Potato blight - threatened crops in Ireland, potato famine 1846 • Toxoplasmosis- found in cat feces, can be fatal to developing fetus

Videos • Pond water video—good amoeba and euglena http://www.youtube.com/watch?v=kB6vgZi99gw • Amoeba eating—good to look at after talking about active transport http://www.youtube.com/watch?v=ojrkxmD6tT8&feature=related

Cellular Processes of ProtistsActive Transport • Moves substances against concentration gradient • Move from HIGH to LOW conc.

Bulk Transport Click Picture for Video • Endocytosis – in to cell (a) • Phagocytosis movement of large solid molecules into the cell • Pinocytosis is the ingestion of extracellular fluid • Exocytosis moves large molecules out of cell (b) • Ex: proteins, waste

Passive(no ATP) Simple diffusion Osmosis Facilitated diffusion High  Low Active(requires ATP) Endocytosis Phagocytosis Pinocytosis Exocytosis Low  High Passive or Active?

Kingdom Protista