February 16th & 18th Notes
February 16th & 18th Notes Bio 102
Popular in Introduction to Biology
verified elite notetaker
Popular in Biology
This 9 page Class Notes was uploaded by Alyssa Shriver on Monday February 22, 2016. The Class Notes belongs to Bio 102 at University of Tennessee - Knoxville taught by Dr. Jeremy Chandler in Spring 2016. Since its upload, it has received 17 views. For similar materials see Introduction to Biology in Biology at University of Tennessee - Knoxville.
Reviews for February 16th & 18th Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/22/16
February 16, 2016 Environments of prokaryotes, classification and the eukaryotic explosion How do microbes acquire the building blocks of biomass? All of Earth’s lifeforms are based on carbon, which they acquire in different ways o Autotrophs fix carbon and assemble into organic molecules (mainly sugars). (Make their food from non living material in the environment) o Heterotrophs use preformed organic molecules. (Rely on other organisms as their food sources) Descriptive prefixes Chemo obtains energy from chemicals in the environment Photo uses light energy to harvest chemical compounds Modes of Nutrition Plant: Photoautotrophs Bacteria: Chemoautotrophs Rhodopseudomonas: Photoheterotrophs Kingfisher: Chemoheterotrophs Bacterial Autotrophs Cyanbacteria o Largest group o In oceans, freshwater, exposed rocks and soil o Photosynthesize o Oldest photosynthetic organisms o Some perform nitrogen fixation Conversion of atmospheric nitrogen into a form that plants can use for growth Do not all rely on sunlight Some obtain energy from geological sources o Inorganic gases of hydrothermal vents Myxococcus xanthus Fruiting bodies for survival SurvivalEndospores Thought to remain in vegetative states indefinitely until conditions are favorable for growth Positive purple Negative pink The cyanobacterium Spirulina It has high carotene concentrations, giving it a distinct pink color A major food for the pink flamingo Limits of Growth The “normal” growth condition are: o Sea level o Temperature 20C40C o Neutral pH o 0.9% salt, and ample nutrients o Any ecological niche outside this window is called “extreme”, and organisms inhabiting them are called extremophiles Some Bacteria Are Highly Resistant to Extreme Environmental Threats Deinococcus Radiodurans o Nickname “Conan the bacterium” o Has the greatest ability to survive radiation of any known organism o Has exceptional capabilities for repairing DNA damaged by radiation o Was genetically engineered for use in bioremediation Philes in Classificiations A lover of or enthusiast of.. word preceeding it In microbial life often coincides with a peak in growth rate Archaea Similar to bacteria Lack a nucleus Genetically distinct “Extremophiles” o Hyperthermophiles Live in extremely hot places o Methanogens Live in oceans hypothermal vents o Halophiles Live in places with high salt content Microbes Classified by Temperature Microorganisms can be classified by their growth temperature o Psychrophiles 020 degrees C o Mesophiles 1545 degrees C o Thermophiles 4080 degrees C o Hyperthermophiles 65121 degrees C All of these organisms have evolved membranes and proteins best suited for their temperatures Microbes in your stomach are classified as Mesophiles Majority of Earth’s atmosphere is cold Cold microbes have adaptation that allows them to survive. We can adapt these abilities for ourselves Microbes that protect themselves from ice Microbes that use ice to get into plants Acidophiles Neurtrophiles Alkaliphiles Aerobes and Anaerobes Strict aerobes can only grow in oxygen Strict anaerobes die in the least bit of oxygen Facultative anaerobes can live with or without oxygen They possess both the ability for fermentative metabolism and respiration (anaerobic and aerobic) If a microorganism does not have a catalase positive, what might this tell you about their environment? It lives in an anaerobic environment Anaerobic reactions between sulfur and iron cause hidden hazards for human technology, such as the corrosion of steel in underwater bridge supports In anaerobic conditions, sulfurreducing bacteria can corrode iron Other specialized structures Cyanobacterial Heterocysts Anabaena differentiates into specialized cells called heterocysts o Allow it to fix nitrogen anaerobically while maintaining oxygenic photosynthesis o Nitrogen fixation from N2 is solely performed by bacteria Microbial Ecology Sergei Winogradsky was among the first to study bacterial in natural habitats Discovered lithotrophs Developed enrichment cultures Built the Winogradsky column Winogradsky and other showed the importance of bacterial in geochemical cycling Important Dates 4.5 billion years ago origin of Earth 3.5 billion years ago prokaryotes dominate 2.5 billion years ago oxygen accumulates (photosynthesis) 2.1 billion years ago eukaryotes first nucleated cells (singlecelled) 1.2 billion years ago first multicelled eukaryotes .5 billion years ago Cambrian explosion of multicellular life Eukaryotic Diversity Eukaryote o Organism with cells characterized by membraneenclosed nucleus and organelles Protists o Eukaryote that cannot be classified as a plant, animal, or fungus o Usually unicellular o Some are heterotrophic o Ancestral to all other eukaryotes o Algae Protozoans Protozoans with flagella are called flagellates and Are typically freeliving, but o Some are nasty parasites Amoebas are characterized by o Great flexibility in their body shape and o The absence of permanent organelles for locomotion o Most species move and feed by the means of pseudopodia (singular, pseudopodium), temporary extensions of the cell Cell Shape and Movement Cilia may extend from nonmoving cells On cells lining the human trachea, cilia help sweep mucus with trapped debris out of the lungs Cilia are not found in prokaryotes Today’s Objectives Practice classifying organisms based on their carbon and energy sources on your own Explain other descriptive terms around “philes, tolerant, and sensitive” organisms Explain how we classify the various extremophiles we mentioned in class based on environments they inhabit Explain the role of catalase in oxygenic systems Explain endosymbiosis and what evidence we have to support it Explain some classifications of protists by locomotion we discussed in class o February 18 Lecture Primitive Eukaryotes continued and the Eukaryotic Explosion Eukaryote o Organism with cells characterized by membraneenclosed nucleus and organelles Amoebas use ___ for movement o Pseudopodia Algae o Algae are Photosynthetic protists whose chloroplasts support food chains in Freshwater rand Marine ecosystems Many unicellular algae are component s of plankton, the communities of mostly microscopic organisms that drift or swim weakly in aquatic environments o Unicellular algae include Dinoflagellates, with Two beating flagella, also External plates made of cellulose Diatoms, with glassy cells walls containing silica and Green algae Can you see algae from space? o Yes, example: algal blooms Emiliania huxleyi diatom o Photosynthetic plankton species covered in calcite disks o Infected by giant viruses causes mass release of discs Seaweeds o Large, multicellular marine algae, o Grow on or near rocky shores o Are only similar to plants because of convergent evolution o Are most closely related to unicellular algae and o Are edible o Classified into three different groups, based partly on the types of pigments, Green algae Red algae Brown algae Slime Molds o Resemble fungi in appearance and lifestyle due to convergence, but o Are more closely related to amoebas o The two main groups are Plasmodial slime molds And unicellular slime molds o Plasmodial slime molds Are named for the feeding stage in their cycle, and amoeboid mass called a plasmodium, Are decomposers on forest floors and Can be large Can solve complex problems with nutrients o Cellular slime molds have an interesting and complex life cycle of successive stages: A feeding stage of solitary amoeboid cells, A swarming stage as a sluglike colony that can move and function as a single cell units and A stage during which they generate a stalklike multicellular reproductive structure Dictyostelium Discoideum o Use cAMP a chemical messenger to coordinate activities Cells that don’t cooperate with the slime mold group will be killed off by the cooperating cells The Origin of Multicellular Life o Colonial protists likely formed the evolutionary links between Unicellular and Multicellular organisms Eukaryotic Diversity: Fungi o Unicellular or multicellular o Eukaryotic o Obtains nutrients by secreting digestive enzymes onto organic matter and absorbing o Decomposers Digest and use organic molecules in dead organisms as sources of nutrients and energy o Body composed of threadlike structures, hyphae o A hypha is a chain of many cells, capable of absorbing nutrients o Hyphae interweave to form mycelium o Mushrooms, mold, yeast List some features of plants.. o Where do they get Energy: from the sun Carbon: photoautotrophs Water and nutrients: from it’s roots o Physical features/ attributes? Eukaryotic Diversity: Plants o Plant Multicellular eukaryote Has cell walls Photosynthetic Autotroph Adapted o Bryophytes Earliest plants Nonvascular plant Lack roots and tissue for transporting water and nutrients Grow only in damp environments Does not produce seeds o Ferns First vascular plant No seeds Vascular tissue keeps stems rigid o Gymnosperms Seedbearing plants “Naked” seeds typically held in cones o Angiosperms Seed plants Seeds in fruit Flowering Today’s Objectives o Explain some unique characteristics of slime molds, algae and fungal organisms Slime molds Resemble fungi in appearance and lifestyle due to convergence but are more closely related to amoebas Plasmodial slime molds o are named after the feeding stage in their life o Are decomposers on forest floors, and can be large Cellular slime molds: o A feeding stage of solitary amoeboid cells, o A swarming stage as a sluglike colony that can move and function as a single unit, and o A stage during which they generate a stalklike multicellular reproductive structure Algae Photosynthetic protists whose chloroplasts support food chains in o Freshwater and o Marine ecosystems Many unicellular algae are components of plankton, the communities of mostly microscopic organisms that drift or swim weakly in aquatic environments Unicellular algae include o Dinoflagellates, with Two beating flagella and External plates made of cellulose o Diatoms, with glassy cell walls containing silica, and o Green algae Fungi Fungus o Unicellular or multicellular o Eukaryotic o Obtains nutrients by secreting digestive enzymes onto organic matter and absorbing o Decomposers Digest and use organic molecules in dead organisms as sources of nutrients and energy o Body composed of threadlike structures, hyphae o A hypha is a chain of many cells, capable of absorbing nutrients o Hyphae interweave to form mycelium o Mushrooms, mold, yeast o Read over the scientific paper discussing farming in slime molds on blackboard o Explain the eukaryotic progression from early protists to more complex multicellular eukaryotes o Explain some main differences between the types of plants we have discussed thus far Bryophytes Lacks roots and tissue for transporting water and nutrients Grow only in damp environments Does not produce seeds Nonvascular plants Ferns No seeds Vascular tissue keeps stems rigid Gymnosperms Seedbearing plants “naked seeds” typically held in cones Angiosperms Seed plants Seeds in fruit Flowering o For next time: rewatch the sun dew video and come up with reasons the plants knew not to eat rocks and paper. We’ll resume group work on some questions next time.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'