Bacteria, Protists, Algae, and Marine Plants

1. Bacteria, Protists, Algae,and Marine Plants ENV 121 Lab

2. Tree of Life Figure 4.24

3. Definitions: Prokaryotes: Unicellular organisms whose cells do not have a nucleus or other organelles, simple Eukaryotes: Unicellular or multicellular organisms with cells possessing a nucleus and other organelles that are enclosed by membranes

4. Definitions: Nutrition: Process by which an organism obtains from its environment 1. Energy 2. Chemical elements (carbon) needed for its survival and growth.

5. Definitions: 1.Energy Phototroph: organisms using sunlight as a source of energy Chemotroph: organisms using chemicals as a source of energy i.e. hydrogen sulfide, ammonia, methane gas

6. 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)

7. Definitions: Primary Producers organisms that manufacture organic matter from CO2, usually by photosynthesis

8. Tree of Life Figure 4.24

9. Domain Archaea • Oldest group of organisms (3.8 billion years) • Prokaryotic cells • DNA analysis – more closely related to eukaryotes • Heterotrophs or Autotrophs • important decomposers, nitrogen fixers

10. Domain Archaea Autotrophs: “extremophiles” 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.

11. 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.

12. Domain Bacteria • Most are heterotrophs • - important decomposers, some are nitrogen fixers • - degrade pollutants • Some are Autotrophs: • Photosynthetic bacteria contain chlorophyll a • Chemosynthetic bacteria use energy released by • breakdown of ammonia, hydrogen sulfide and other sulfur or iron compounds

13. Domain Bacteria • Cyanobacteria(formerly “blue-green algae”) • most primitive plant-like organisms • Photoautotrophic bacteria • Prokaryotic cells • Pigments: chlorophyll a, phycocyanin, and phycoerythrin • Important role in O2 accumulation in our atmosphere, some • carry out nitrogen fixation • Solitary or colonial • ****DRAWING****

14. Domain Bacteria Prochlorococcus Synechococcus

15. Kingdom Protista • General information: • Often separated into many different Kingdoms • Variation in cellular anatomy, ecological role, and • life cycles • Planktonic, unicellular, and multicellular • Structure: • Mostly unicellular – complex an organism as any • whole plant or animal • Size range: 0.8 to 2,000 μm (=2mm), larger than • bacteria

16. Kingdom Protista • Feeding: • Some are photoautotrophs  phytoplankton • Some are heterotrophs  zooplankton • Others are mixotrophs  Euglena sp. • Locomotion: • Flagella or cilia

17. Kingdom Protista • Phytoplankton: • Make up ~1% of global chlorophyll biomass, but are responsible for ~50% global photosynthesis • Are the base of the oceanic food web • Regulate global climate • Sink for atmospheric CO2 Chl a Absorbance

18. 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

19. Photosynthetic Protists: • Diatoms • “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 • Reproduction: • Asexual = Cell division • Sexual  egg + sperm in auxospore stage • ****DRAWING****

20. 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 naked • Have chlorophyll, can also ingest food particles • Have Chlorophyll a, Chlorophyll c2, and peridinin Photosynthetic Protists: Fig. 5.7 Gonyaulax polyedra

21. Photo by DC Tulipani, 8/2003 Photosynthetic Protists: • Dinoflagellates • 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***** Zooxanthellae from anemone, Bartholomea annulata

23. http://www.whoi.edu/redtide/

25. Photosynthetic Protists: • Coccolithophores: (Class Haptophyta) • Covered with small calcareous coccoliths • Flagellates • Major source of primary production • <20µm in diameter

26. 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

27. Foraminiferans • Most live on bottom, free or attached • Important contributors in coral reefs and sandy beaches (Bermuda’s “pink” beaches) Non-photosynthetic Protists: ****DRAWING****

28. http://earthguide.ucsd.edu/earthguide/imagelibrary/orbulinauniversa.htmlhttp://earthguide.ucsd.edu/earthguide/imagelibrary/orbulinauniversa.html http://www.ucl.ac.uk/GeolSci/micropal/foram.html

29. Fig. 5.11 Non-photosynthetic Protists: • Radiolarians (Phylum Polycystina) • Planktonic, marine • Secrete tests made of silica (SiO2) • Tests typically spherical with • radiating spines • psuedopodia – diatoms (Why?) • Open waters throughout ocean • Shells settle to bottom and form siliceous ooze, called radiolarian ooze • ****DRAWING****

30. Non-photosynthetic Protists: • Genus Euglena • ~150 species, freshwater • Flagellum used for locomotion • Mixotrophs: • Contain chlorophyll  photosynthesize • Some eat small particles of living matter Euglena acus Euglena spirogyra

31. Photosynthetic Protists: Multicellular Algae • General Structure: • More complex than unicellular algae • Still lack the highly specialized structures and reproductive mechanisms of land plants Fig. 6.1

32. Photosynthetic Protists: Multicellular Algae • Phylum Chlorophyta: “Green algae” • Contain chlorophyll a – no pigment to mask • Unicellular (3 examples - DRAWINGS) • Desmids • Volvox sp. • Cladophora sp. • Multicellular (2 examples - DRAWINGS) • Ulva sp. • Codium sp. Ulva sp. Codium fragile

33. 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.

34. Pelagophycus Pelagophycus Macrocystis Egregia

35. Photosynthetic Protists: Multicellular Algae • Phylum Rhodophyta: “Red algae” • 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? • 2 examples – DRAWINGS • Corallina sp. (calcified)

36. Pelagophycus Halimeda Porphyra