Cell Diversity and Photosynthesis Diversity of Metabolisms Photosynthesis

Cell Diversity and Photosynthesis • • • Diversity of Metabolisms Photosynthesis Prokaryotic and Eukaryotic Cells Prokaryotes—Archaea and Bacteria Eukaryotes—Protists, Plants, Fungi, Animales • Viruses and Phages Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Basic metabolic requirements • • Energy to build carbon chains Oxygen…sometimes Nitrogen, Iron and other chemicals Physical environment Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Energy and Carbon sources Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Depending on carbon and energy source: • • Photoautotrophs: CO 2, light Photoheterotrophs: organics, light Chemoautotrophs: CO 2, chemical Chemoheterotrophs: organics, chemical Thought question: Which is most common among macrobiological organisms? What are we? Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Photosynthesis overview Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Photosynthesis I. Light reaction (Photosystem I and II are part of this) Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Photosynthesis II. Calvin cycle Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Other chemical requirements • Nitrogen: necessary component of amino acids and nucleotides, can be limiting, nitrogen-fixing bacteria (Rhizobium) very important in food chain • Iron, may be limiting factor in bacterial survival (reading from “Why we get sick? ”) • Common ions: sodium, phosphorous, potassium, chlorine, magnesium, calcium Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Physical aspects of cell’s environment • Temperature—how hot is it? • p. H—how acid is it? • Water osmotic pressure—how salty is it? • Water hydrostatic pressure—how deep is it? • More on these factors in Unit III Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Overview of Diversity Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Prokaryotes—simple cells with no organelles The primitive Archaea are frequently "extreme-ophiles, " including these heat-tolerant forms that live in hot springs Electron micrograph of rod-shaped bacteria--Bacillus? Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Prokaryotes—simple cell division, no chromosomes Larry M. Frolich, Ph. D. Biology Department, Yavapai College

• Typical shapes of prokaryotic cells • Cells are tiny—as small as 1 micron Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Archaea • Archaea are a group of bacteria-like prokaryotes that are believed to be very close to the root of the tree of life • Characteristics of Archaea (different from bacteria): Archaea in solar evaporation ponds near San Francisco Bay--often have red or orange pigment to protect them from intense solar energy – Lack peptidoglycan in cell wall – Cell membrane lipids with branched hydrocarbon chains – AUG start codon for protein precursor is methionine (like eukaryotes) and not Nformylmethionine (like bacteria) Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Archaea Principally "extremophiles“ – live in harsh environments: – Thermophiles – Halophiles--highly saline habitats like Dead Sea, Great Salt Lake and solar evaporation ponds for salt production – Methanogens--obligate anaerobes in high methane environments-deep sea vents, colons of animals, sewage treatment plants Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Bacteria Cell Shapes and Groupings Cocci—rod-shaped bacteria Bacilli—ball-shaped bacteria Larry M. Frolich, Ph. D. Biology Department, Yavapai College

• Lots of bacterial groups!! Lots of bacteria!! • closeness of disks shows similarity of r. RNA sequence See course website for link to images, descriptions of bacterial groups Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes • Ciliates • Have cilia around cell to propel and encounter environment • Paramecium being devoured by Didinium (at right) Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes • Apicomplexans • All pathogens of animals • Includes Plasmodium-protozoan that causes malaria (life cycle at right) Larry M. Frolich, Ph. D. Biology Department, Yavapai College

• • • Dinoflagellates photosynthetic using carotene and chlorophylss make up large part of freshwater and marine plankton Often have protective "skeleton" of silica (at right) that frequently forms fossils Many are bioluminescent Some produce neurotoxins that can poison fish are people who handle infected fish Eukaryotes Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes • • • Amoebae not clear where amoebae belong in taxonomic scheme or if they are all related all feed and move with pseudopodia lack mitochondria include Radiolarians and foraminifera (planktonic forms with silica and calcium carbonate armor) At right is typical amoeba and Radiolarian Larry M. Frolich, Ph. D. Biology Department, Yavapai College

• Euglenozoa • have choloroplasts • lack cell walls and have flagella • plant allies or animal allies-own kingdom? ? • Euglena, at right, is classic example Eukaryotes Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes-- Fungi • Soil decomposers • Mycorrhizae--fungal filaments on roots of plants (90% of plants have them) help to absorb minerals and water • Nutritious food source--mushrooms • Important spiritual source--hallucinogenic forms • Produce antibiotics (penicillin, etc. ) • Food preparation--bread, alcohol, citric acid for soft drinks and other prepared drinks) • All fungi reproduce by cell division or asexually • Almost all have sexual reproduction by budding, asexual spores or sexual spores on thalli or fruiting bodies (large mushrooms are example) • Basidiomycota is mushroom group • Ascomycota is mold and yeast group Larry M. Frolich, Ph. D. • Zygomycota is small, mostly parasitic group, also includes some molds Biology Department, Yavapai College

Penicillin with asexual spores at ends Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes-- Lichens • symbiotic fungus and cyanobacteria growing together • sometimes algae replaces cyanobacteria • sometimes not symbiotic in that fungus kills photosynthetic component • important soil forming organism--break down new rock • good air quality indicators--do not grow in polluted environment Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes-- Algae • Seaweed is multicellular algae-most seaweeds have single-cell part of life cycle • Many algaes only live as singlecelled form • Important component of marine plankton, especially diatoms • Several groups of algaes--green algae, red algae, yellow, golden and diatoms, brown algae • Diatoms have cell walls, composed of silica and cellulose --the silica often fossilizes and forms huge diatomaceous deposits much sought-after by gardeners for their high silica content and light weight porous nature Diatom frustrules (two halves fit together like petri dish) Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Eukaryotes– Water Molds and Slime Molds • Previously grouped with fungi, but significant differences • Water molds decompose dead animals in aqueous environment, also parasitic forms--Irish Potato famine caused by Phytophthora or late blight, still most damaging potato crop disease to this day. • Slime molds may represent early forms of sexual reproduction-complex life cycle with large multi-nucleated, mobile (in amoeba-like form), synchtiums. Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Viruses and Phages • All are obligatory intracellular parasites--need to be inside a prokaryotic or eukaryotic cell to reproduce • Viruses infect eukaryotic cells; phages infect prokaryotic cells • Virus particles, when outside of cells, cannot be seen in light microscope--size is 10 -300 nm • Particle consists of nucleic acids surrounded by one or two protein coats and sometimes protein appendage Larry M. Frolich, Ph. D. Biology Department, Yavapai College

Viruses and Phages Viruses reproduce by making copies of proteins and nucleic acids inside host celll Larry M. Frolich, Ph. D. Biology Department, Yavapai College

• • • Viruses are characterized and grouped according to what kind of nucleic acids are found in the particles, and therefore how they reproduce themselves within cells. RNA viruses require reverse transcriptase (to go from RNA to DNA) which has been very important in genetic engineering: viruses types are ds. DNA, ss. RNA, ds. RNA, retroviruses (ds=doublestranded; ss=single-stranded) Viruses do not all causes infectious diseases and may be involved in normal development or secondary factors in cancers, diabetes and other conditions Viroids are small circular pieces of RNA without any protein capsid that infect plants Prions ("PROteinaceous INfective agents) are proteins that can convert cells into a disease state Viruses and Phages Larry M. Frolich, Ph. D. Biology Department, Yavapai College