Microbiology: Chapter 4
Microbiology: Chapter 4 Bio 221
Popular in Microbiology
verified elite notetaker
Popular in Biology
This 6 page Class Notes was uploaded by Savannah Carter on Wednesday September 14, 2016. The Class Notes belongs to Bio 221 at College of Western Idaho taught by Teresa Rich in Fall 2016. Since its upload, it has received 19 views. For similar materials see Microbiology in Biology at College of Western Idaho.
Reviews for Microbiology: Chapter 4
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/14/16
Microbiology: Chapter 4 – Eukaryotic Structure History of Eukaryotes o Last Common Ancestor All cells came from the last common ancestor Characteristics common to bacteria, archaea, and eukaryotes Groups split up and developed their own unique characteristics o Endosymbiosis One organism lives inside another one The evolutionary development of different cell structures Nucleus Pinched off from the cytoplasm and surrounded DNA Endoplasmic Reticulum Pinched off from the cell membrane Mitochondria Was a prokaryotic organism that was engulfed by the eukaryotic cell It helped the cell rather than hurt it, so it was not destroyed Produce ATP Have their own DNA o Most closely related to E. Coli Chloroplasts A photosynthetic bacterium was engulfed by the eukaryotic cell It helped the cell rather than hurt it, so it was not destroyed Have their own DNA o Most closely related to cyanobacteria o Multicellular Organisms Most eukaryotes are unicellular Most protozoa, fungi, and algae Cells work together and each have their own jobs Humans, plants, animals, some fungi, some algae Eukaryotic Cell Structure o External Structures Flagella Bundles of microtubules in a 9+2 arrangement o ATP is used to pull the bundles back and forth to move the cell Bacteria Motion – turn 360 , like a propeller Eukaryote Motion – wave back and forth Cilia Short flagella Same arrangement – bundles of microtubules (9+2) Move coordinately Glycocaylx Composed of polysaccharides Same as the extracellular matrix Functions protection, attachment, communication o Boundary Structures Cell Wall Fungi Composition – chitin Algae Composition – cellulose Animals and protozoa never have cell walls Cell Membrane Phospholipid bilayer Contains sterols o Provide stability (vital for cells without cell walls) Semipermeable Transmembrane Proteins o Move large substances in and out o Internal Structures Nucleus Contains DNA Double membrane with pores Contains nucleolus o Produces rRNA o Produces subunits of ribosomes Endoplasmic Reticulum The factory that makes things Contains enzymes that synthesize molecules Rough studded with ribosomes, makes proteins, receive mRNA Smooth studded with enzymes, synthesize carbs and lipids Golgi Apparatus Post office that packages things Enzymes modify macromolecules from the ER Lysosomes Contains digestive enzymes Pinch off from the cell membrane Vacuoles UPS trucks that transport things Can fuse with lysosomes Pinch off from the cell membrane Can contain food, waste, things that need to be moved in/out/around Mitochondria Energy producers Smooth outer membrane Folded inner membrane Have their own DNA and 70S ribosomes Chloroplasts Oxygen producing photosynthesis Inner and outer membrane Have their own DNA and 70S ribosomes Found in algae, plants, protozoa Cells that have chloroplasts always have mitochondria too Ribosomes 80S in eukaryotes Make protein Composed of protein and rRNA Bound or free floating Cytoskeleton Gives support and shape to the cell Can change the cell shape Transports things around the cell Composed of o Actin Filaments smallest, cell division, contraction, extension, pinching off of lysosomes and vacuoles o Intermediate Filaments structural reinforcement, cell to cell connections o Microtubules largest, form the mitotic spindle, internal structure of cilia and flagella, structure for cells w/o a cell wall Fungi o Characteristics Eukaryotes Chitin in cell walls Do not photosynthesize Absorb nutrients from the environment Unicellular (yeast) or multicellular (mold and mushrooms) o Structure Unicellular Round Yeast Multicellular Hyphae: long, branching filamentous cells o Combine to form mycelium: the vegetative part Mycelium is visible to the naked eye Dimorphic: sometimes like a yeast, sometimes like a mold Yeast-like at body temperature Mole-like at room temperature o Pathogens Humans are very resistant to fungal infections Most cause mild symptoms Opportunistic pathogens: cause disease when they have an opportunity People with compromised immune systems After good bacteria are wiped out from antibiotics o Nutrition Release enzymes into their surroundings to break down food into small enough molecules to be moved into the cell Cell wall prevents large chunks Saprobe: food is dead Parasite: food is alive “kings of digestive enzymes” o Benefits to Humans Mushrooms Add flavor to cheese Make bread Make beer and wine Clean up natural disasters o Reproductive Strategies Asexual Reproduction Done by all fungi A fungus clones itself through mitosis Spore Formation Resistant forms Resist drying, lack of food Sexual Reproduction Combines 2 different genomes to create genetic diversity o Hope that the genetically different offspring will be better suited to the environment than either parent Two of the same species fuse a haploid cell to create a new diploid cell Diploid cell forms spores through meiosis that form new fungi Protozoa o Organisms that do not fit in with other eukaryote groups o Locomotion Pseudopods: temporary extensions of cells (false feet) Engulf prey by wrapping their pseudopods around them Cilia Flagella Non-motile – wait for the environment or a vector to move them o Nutrition Heterotrophic: eat other creatures Rather than making sugars from sunlight Some non-pathogenic protozoa are photosynthetic Mixotrophs: heterotrophic and photosynthetic o Habitat Range Found anywhere moist Cysts form in dry environments o Life Cycle Alternate between TROPHOZITE (feeding stage) and CYST (resting stage) Cysts are resistant to drying, lack of food, and are hard to kill o Classification of pathogens Grouped by their method of motility Sarcodina Pseudopods Ciliophora Cilia Mastigophora Flagella Sporozoa Gliding Helminths o General Worm Morphology Cells don’t have cell walls Multicellular Animals Groups Roundworms (nematodes) o Most are nonpathogenic and essential to the environment Flatworms o Flukes (trematodes) o Tapeworms (cystoids) o Life Cycle and Reproduction Start as fertilized eggs/embryos Develop into larvae Matures into an adult that produces eggs o Schistosoma Life Cycle Starts as a fertilized egg in a human intestine Excreted into an aquatic environment Egg develops into a larva and enters a snail Develops into a second-stage larva and leaves the snail Bores through the skin of the legs or feet of a human, enters the blood stream and looks for the intestine Matures into an adult Reproduces a large number of eggs hoping some will survive Can last for years and cause chronic inflammation o Pin Worm Life Cycle Causes inflammation of the intestine A human swallows microscopic eggs picked up from another infected person Eggs hatch in the intestine and release larva that mature into adults Male and female worms mate Female worm migrates out to the anus to deposit eggs Eggs cause intense itchiness Scratching contaminates the fingers, and everything they touch Infects others and reinfects the original human o Distribution - Found everywhere humans live