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Bacteria, Protists, and Algae,. ENV 121 Lab. Goals. To provide a solid foundation in science To collect, assimilate and convey scientific information To appreciate the diversity of life in the ocean
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Bacteria, Protists, and Algae, ENV 121 Lab
Goals • To provide a solid foundation in science • To collect, assimilate and convey scientific information • To appreciate the diversity of life in the ocean • To foster a sense of responsibility/stewardship for conservation/preservation of ocean environment, resources
“Earth’s richest seascape” Sharks that walk on fins and more Islands off New Guinea • “species factories”, dozens of new fish (2 new sharks), shrimp, coral • Most biodiverse marine area anywhere • Study Area ~ 2 football fields had 250 coral species (4 x Caribbean), total area = 45 mil acres, 600 sp (75% of world’s known total) • Threats include fishing with dynamite, cyanide, commercial fishing, poor water quality
Bioprospecting: • Scientific search for organisms in nature that may provide medical cures, vaccines, alternative fuel, detergent, you name it!
Tree of Life Figure 4.24
Definitions: Prokaryotes: Greek-Pro = before, karyon = kernal Unicellular organisms whose cells do not have a nucleus or other organelles, simple Eukaryotes: Eu = true, karyon = kernal Unicellular or multicellular organisms with cells possessing a nucleus and other organelles that are enclosed by membranes
Definitions: Nutrition: Process by which an organism obtains from its environment 1. Energy 2. Chemical elements (carbon) needed for its survival and growth.
H H S Definitions: 1.Energy Phototroph: + 6H2O + 6CO2 C6H12O6 + 6O2 organisms using sunlight as a source of energy Chemotroph: organisms using chemicals as a source of energy, use hydrogen donors other than water i.e. hydrogen sulfide, ammonia, methane gas
Definitions: 2.Obtain Carbon molecules Autotroph: organisms capable of synthesizing their own food from simple inorganic molecules (e.g. carbon from CO2) Heterotroph: organisms that obtain food from organic compounds (i.e. other living organisms) (e.g. carbon from glucose)
Definitions: Primary Producers organisms that manufacture organic matter from CO2, usually by photosynthesis
Tree of Life Figure 4.24
Domain Archaea Methanothermus • Oldest group of organisms (3.8 billion years) • Prokaryotic cells • DNA analysis – more closely related to eukaryotes • Heterotrophs or Autotrophs • important decomposers, nitrogen fixers Methanococcus
Domain Archaea Autotrophs: “extremophiles”- although not all are Methanogens – chemoautotrophs that produce methane gas from CO2 and hydrogen gas. Halophiles – live in high salt environments, some are photoautotrophs (performing photosynthesis) Thermophiles – live in environments of very high temperatures, like hot springs or near hydrothermal vents.
Tree of Life Figure 4.24
Domain Bacteria • Structure: • unicellular • Size ranges from 0.5 to 15 μm, among smallest living organisms • Prokaryotic cells • Shapes include: spheres, spirals, rods, and rings • Reproduction: • Simple asexual division • Generation time = 1-3 hrs.
Domain Bacteria • Heterotrophs (most) • - important decomposers (natural recyclers of essential nutrients • - found everywhere, especially in bottom sediments • - some are nitrogen fixers (chief process by which atmospheric nitrogen enters biosphere, becomes available nutrient to other organisms • - degrade pollutants • Autotrophs (some): make own organic compounds, both phototrophs and chemotrophs as before • Photosynthetic bacteria contain chlorophyll a • Chemosynthetic bacteria use energy released by • breakdown of ammonia, hydrogen sulfide and other sulfur or iron compounds, e.g., (e.g., Pseudomonas-oil eating bacteria)
Domain Bacteria • Cyanobacteria(form. “blue-green algae”) *DRAWING* • most primitive plant-like organisms • Photoautotrophic bacteria – what does this mean? • Prokaryotic cells specialized to perform photosynthesis • Pigments: chlorophyll a, phycocyanin (namesake), and phycoerythrin (red pigment) • Important role in O2 accumulation in our atmosphere, some • carry out nitrogen fixation • Solitary or colonial • ****DRAWING of Nostoc**** • Observe purple with blue outer fringe, string of pearls
Domain Bacteria Reduce N2 to NH3, fixation Prochlorococcus Synechococcus
Tree of Life Figure 4.24
Kingdom Protista • General information: • Variation in cellular anatomy, ecological role, and • life cycles • Planktonic, unicellular, and multicellular • Plankton, planktos=wandering, • Communities that drift passively or swim weakly • Eukaryotes – what are these again? • Unicellular or multicellular organisms with cells possessing a nucleus and other organelles that are enclosed by membranes • Structure: • Mostly unicellular – however, complex an organism as any • whole plant or animal • Size range: 0.8 to 2,000 μm (=2mm), larger than • bacteria
Kingdom Protista • Feeding: • Nearly all are aerobic in metabolism (use mitochondria for cellular respiration) • Some are photoautotrophs phytoplankton • Some are heterotrophs (absorb or ingest organic matter (food) zooplankton • Others are mixotrophs Euglena sp. • Locomotion: • Flagella or cilia
Kingdom Protista • Phytoplankton: • Make up ~1% of global chlorophyll biomass (small in size, structure), but are responsible for ~50% global photosynthesis (important function) • Are the base of the oceanic food web • Sink for atmospheric CO2
Diatoms: (Class Bacillariophyta) • ~ 12,000 species, half are marine • Unicellular, but aggregate • Centric (cylindrical): planktonic • Pennate (boat-shaped): benthic • Enclosed by cell walls made of • silica (SiO2) • Yellow and brown color carotenoid pigment is fucoxanthin PhotosyntheticProtists: Fig. 5.5 Pennate
Photosynthetic Protists: Diatoms • Diatoms (*DRAWING*) • “Shell” Frustule • light passes through holes • perforations allow gasses and nutrients • Frustules of dead diatoms diatomaceous ooze • Important primary producers – temperate and polar regions • Can produce domoic acid (deadly neurotoxin) • Reproduction: • Asexual = Cell division • Sexual egg + sperm in auxospore stage • ****DRAWING**** Asexual Sexual
Photosynthetic Protists: • Dinoflagellates: (Class Dinoflagellata) • ~ 1,200 species, all marine • Important primary producers – • Warm regions • Unicellular • 2 unequal flagella • External cell wall armored with plates made of cellulose or have no cell wall • Have chlorophyll, can also ingest food particles • Have Chlorophyll a, Chlorophyll c2, and peridinin Fig. 5.7 Gonyaulax polyedra
Photo by DC Tulipani, 8/2003 Photosynthetic Protists: • Dinoflagellates (*DRAWING*) • Massive blooms cause “red tides” • Some release toxins that cause shellfish poisoning (PSP, NSP, DSP) • Some bioluminesce • Some are symbiotic to other organisms and called zooxanthellae • ****DRAWING***** • Prorocentrum and Ceratium Pyrocystis Zooxanthellae from anemone, Bartholomea annulata
Ceratium and Prorocentrum http://www.nmnh.si.edu/highlight/sem/highlight/dinos/dinoflagellates.htm
http://www.whoi.edu/redtide/ Red tides: Begin by sudden increase in dinoflag. Water becomes “colored” at 200,000 – 500,000 cells/liter
Photosynthetic Protists: • Coccolithophores: (Class Haptophyta) • Covered with small calcareous coccoliths • Flagellates • Major source of primary production • <20µm in diameter
Non-photosynthetic Protists (Zooplankton): • Foraminiferans: (Phylum Granuloreticulosa) • foramen = little hole, ferre = to bear • Planktonic protozoans (animal-like protists), • exclusively marine • Shells (tests) made of calcium carbonate • (CaCO3) • “Amoeba with a shell” • Pseudopodia • Shells of planktonic forams sink to bottom to • form foraminiferan ooze
Foraminiferans (*DRAWING*) • Most live on bottom, free or attached • Important contributors in coral reefs and sandy beaches (Bermuda’s “pink” beaches) Non-photosynthetic Protists: ****DRAWING****
http://earthguide.ucsd.edu/earthguide/imagelibrary/orbulinauniversa.htmlhttp://earthguide.ucsd.edu/earthguide/imagelibrary/orbulinauniversa.html http://www.ucl.ac.uk/GeolSci/micropal/foram.html
Fig. 5.11 Non-photosynthetic Protists: • Radiolarians (Phylum Polycystina) • Planktonic, marine • Secrete tests made of silica (SiO2- glass) • Tests typically spherical with • radiating spines • pseudopodia – diatoms (Why?) • Open waters throughout ocean • Shells settle to bottom and form siliceous ooze, called radiolarian ooze • ****DRAWING****
Protists: • Genus Euglena *DRAWING* • ~150 species, freshwater • Flagellum used for locomotion • Mixotrophs: • Contain chlorophyll photosynthesize • Some eat small particles of living matter Euglena acus ***DRAWING*** Euglena spirogyra
Photosynthetic Protists: Multicellular Algae • General Structure: • More complex than unicellular algae • Still lack the highly specialized structures and reproductive mechanisms of plants Fig. 6.1
Photosynthetic Protists: Multicellular Algae • Phylum Chlorophyta: “Green algae” • Contain chlorophyll a • Unicellular (DRAWINGS) • Volvox sp. • Multicellular (2 examples - DRAWINGS) • Ulva sp. Ulva sp. Volvox sp. Codium fragile
Photosynthetic Protists: Multicellular Algae • Class Phaeophyta: “Brown algae” • Multicellular, mostly marine • Olive-green to dark brown color from carotenoid pigment: Fucoxanthin • Also have chlorophyll a and c • Often dominant primary producers on temperate and polar rocky shores • 2 examples - DRAWINGS • Macrocystis pyrifera • Egregia sp. REMEMBER, WHERE ARE THE: Blade Stipe Pneumatocyst Holdfast
Pelagophycus Pelagophycus Macrocystis Macrocystis Egregia
Photosynthetic Protists: Multicellular Algae • Phylum Rhodophyta: “Red algae” (**Drawings**) • Essentially marine, all multicellular • Common, more species than green/brown combined • Contain red pigments called phycobilins • Most are soft bodied, • some coralline reds encrusted with hard calcium carbonate, Why? Reef-building, stabilizing • 2 examples – DRAWINGS • Corallina sp. (calcified) • Ceramium (slide)
Pelagophycus Halimeda Porphyra - nori
1st Lab practical • Stations around the room with a microscope and slide, photo, or large object to examine • Give 1 minute to answer questions before moving on to next station • 17-18 questions, total worth 25 points • Make a study guide from lecture notes • Need to identify organisms • Name something important about them • Memorize the definitions used in this lab
Example lab practical question: (2 pts) What type of organism is this? _____________ Their frustules are made of __________. They dominate in __________waters and when they sink, form ______________ at the bottom of the ocean. (Diatom Picture)