Flashcards About Test on Exam 1 – Microbiology
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| Antoni van Leeuwenhoek |
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| Dutch (1623-1723) first microscopes. Viewed "beasties"- microbes. He was able to view bacteria, archea, fungi, algae, single-celled protozoa, and small multi-cellular animals. |
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| microorganism/microbe |
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| an organism too small to be seen without a microscope |
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| Carolus Linnaeus |
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| Swedish (1707-1778) developed taxonomic system for naming plants and animals and grouping similar organisms together. |
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| prokaryotes |
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| -lack nuclei and unicellular -includes bacteria and archea -reproduce asexually |
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| bacteria (ch1 definition) |
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| prokaryotic microorganisms typically having cell walls composed of peptidoglycan. |
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| archea (ch1 definition) |
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| -prokaryotic organisms with cell walls that contain polymers other than peptidoglycan -found in extreme environments such as acidic hot springs, swamp mud, or Great Salt Lake -not known to cause disease |
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| eukaryotes |
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| any organism made up of cells containing a nucleus composed of genetic material surrounded by a distinct membrane. includes animals, plants, algae, fungi, and protozoa |
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| fungi |
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| -eukaryotic microbes with cell walls -obtains food from other organisms (heterotrophic) -possess cell walls -includes molds and yeast |
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| heterotrophic |
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| an organism which must obtain food from other organisms |
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| mold |
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| -multicellular fungi -grows in long filaments -distinguishable from yeast with the presence of hyphae/mycelium -reproduces by sexual and asexual spores |
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| yeast |
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| -unicellular fungi -reproduce asexually by budding -some produce sexual spores -responsible for bread rising and alcohol fermentation |
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| protozoa |
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| -greek for "first animals" -similar to animals in nutrient needs and cellular structure -single-celled eukaryotes -live freely in water; some live in animal hosts -asexual (most) and sexual reproduction *categorized by locomotion: pseudopodia, cilia, or flagella |
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| algae |
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| -unicellular or multicellular eukaryotes **photosynthetic -unicellular common in fresh water -largest examples are seaweed and kelp -differ from plants due to their simple reproductive structures |
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| viruses |
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| -acellular obligatory parasites -composed of genetic material surrounded by a protein coat -could not be seen until the electron microscope was invented in 1932 |
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| Golden Age of Microbiology the general questions of that time |
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| -is spontaneous generation of microbial life possible-what causes fermentation-what causes disease-how can we prevent infection and disease? |
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| abiogenesis |
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| -aka "spontaneous generation" -living thing can arise from nonliving matter -proposed idea of Aristotle (384-322 BC) |
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| Francesco Redi |
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| Italian physician (1626-1697) ->demonstrated experiments with decaying meat and maggots. covered jars lacked the presence of maggots. ->first to provide doubt in spontaneous generation. |
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| John T Needham |
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| British investigator(1713-1799) ->supported spontaneous generation theory with gravy & infusion boiling experiments ->he explained there must be a "life force" |
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| Lazarro Spallanzani |
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| Italian scientist(1729-1799) ->repeated Neeham's experiments with tighter seal and longer boil to point out its flaws -refuted against spontaneous generation -his findings were still unaccepted (until Pasteur) |
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| Louis Pasteur |
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| "father of microbiology" (1822-1895) ->finally disproved the spontaneous generation theory by boiling infusions with swan-neck bottles. ->fermentation: by experimenting with grape juice and yeast in sealed versus unsealed flasks, Pasteur proved that bacteria ferments grape juice to produce acids while yeast alone ferments grape juice to produce alcohol ->pasteurization: process of heating grape juice just enough to kill most contaminating bacteria without changing the juice's basic qualities. ->created the germ theory in 1857 ->responsible for the field of biotechnology or industrial microbiology |
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| scientific method |
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| -process by which scientists prove or disprove hypotheses through observations of the outcomes of carefully controlled experiments -the debate over spontaneous generation led in part to the development of generalized scientific method |
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| biotechnology |
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| -aka industrial microbiology -intentionally using microbes to manufacture products -Pasteur responsible for developing this field (with his pasteurization) |
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| Eduard Buchner |
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| -German scientist 1897 -demonstrated that fermentation did not require living cells ->began the field of biochemistry and study of metabolism, also genetics |
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| biochemistry |
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| -branch of chemistry which studies the chemical reactions of living things -E. Buchner responsible for beginning this field -Kluyver & van Niel (early 1920s): microbes as model sytems fro biochemical reactions |
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| Fracastoro |
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| Italian philosopher (1478-1553) -1546, first to conjecture that "germs of contagion" cause disease |
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| germ theory of disease |
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| theory developed in 1857 by Pasteur which suggested that microbes are responsible for diseases |
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| pathogen |
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| microorganism capable of causing disease |
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| etiology |
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| -study of the causation of disease -Robert Koch responsible for creation of this field |
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| Robert Koch |
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| German doctor (1843-1910) ->examined the blood of anthrax infected animals and injected endospores of bacteria into mice -first to prove that batcerium cause disease ->Koch also responsible for culture & colonization: took samples of specimens and used potatoes or gelatin as a medium to allow the bacteria and fungi to multiply and form distinct colonies **each colony consists of the progeny of a single cell Koch's other contributions: -simple staining techniques -first photomicrograph of bacteria -first photomicrograph of bacteria in diseased tissue -use of steam to sterilize -use of Petri dishes |
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| Koch's postulates |
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| a series of steps that must be taken in order to prove the cause of infectious disease: 1. The suspected causative agent must be found in every case of the disease and absent from healthy hosts. 2. The agent must be isolated and grown outside the host. 3. When the agent is introduced to the healthy, susceptible host, the host must get the disease. 4. The same agent must be found in the diseased experimental host. |
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| Charles Leveran |
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| 1845-1922: used Koch's postulates to prove that a particular protozoa caused malaria |
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| Edwin Klebs |
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| 1834-1913: used Koch's postulates to find the bacteria which causes diptheria |
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| Ivanowski and Beijernick |
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| 1851-1931: tobacco plant pathogen. described "filterable viruses" (now just called viruses) Ivanowski: responsible for virology Beijernick: environmental microbiology |
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| Walter Reed |
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| 1900: proved that viruses could cause diseases such as yellow fever in humans |
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| Hans Christian Gram |
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| Danish scientist (1853-1938) ->developed a the staining technique in 1884 -now called Gram-positive (purple) and Gram-negative (pink) |
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| nosocomial infections |
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| infections acquired in a health care setting |
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| Ignaz Semmelweis |
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| Vienna physician (1818-1865) ->first to suggest handwashing after infants were dying of puerperal fever -he theorized that students carried "particles" from cadavers to the delivery rooms |
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| Joseph Lister |
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| English surgeon (1827-1912) ->became founder of antiseptic surgery. |
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| Florence Nightingale |
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| English nurse (1820-1910) ->introduced cleanliness and antiseptic techniques to nursing throughout the Crimean War ->notable for nursing education |
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| John Snow |
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| English physician (1813-1858) ->studied the occurrences of cholera & showed that they centered around public water supply -supported the need for adequate sewage treatment and pure water supply *foundation for 2 branches of microbio- infection control & empidemiology |
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| Edward Jenner |
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| English physician (1749-1823) ->first to vaccinate a boy with the cowpox to immunize against small pox [named vaccination after vaccinia virus, which causes cowpox] *began the field of immunology. |
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| Paul Ehrlich |
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| German microbiologist (1854-1915) ->studied chemicals to find a "magic bullet" that would destroy pathogens while remaining nontoxic to humans *began the branch of medical microbiology known as chemotherapy |
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| Alexander Fleming |
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| -1929: discovered penicillin -responsible for pharmaceutical microbiology |
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| Beadle & Tatum |
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| microbial genetics |
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| microbial genetics |
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| functions of DNA and RNA -Beadle and Tatum |
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| molecular biology |
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| combines aspects of biochemistry, cell biology, and genetics -specifically interested in genome sequencing -branches include: genetic engineering and gene therapy -Pauling & Woese |
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| Pauling & Woese |
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| molecular biology genetic engineering gene therapy |
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| recombinant DNA technology |
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| type of biotechnology in which scientists change the genotypes and phenotypes of organisms |
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| gene therapy |
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| use of recombinant DNA technology to insert a missing gene or repair a defective gene in human cells |
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| bioremediation |
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| the use of living bacteria, fungi, and algae to detoxify polluted environments |
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| environmental microbiology |
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| branch of microbiology studying the role of microorganisms in soils, water, and other habitats -Beijernick & Winogradsky |
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| von Behring & Kitasato |
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| their studies developed into serology and immunology |
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| George Domagk |
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| 1935: discovered use of sulfa drugs -pharmaceutical microbiology |
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| Kluyver & van Niel |
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| -early 1920s: microbes as model systems for biochemical reactions -contributed to biochemistry |
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| valence |
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| combining capacity of an atom -positive if has electrons to give up -negative if has spaces to fill -stable when outer electron shells contain full capacity |
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| chemical bonds |
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| attachment of atoms combined by sharing or transferring valence electrons |
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| atomic number |
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| number of protons in nucleus |
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| atomic mass |
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| sum of protons and neutrons |
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| isotope |
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| atoms of a given element that differ in number of neutrons |
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| electronegativity |
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| sharing of atoms for electrons; the more electronegative an atom, the greater the pull its nucleus exerts on electrons |
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| SPONCH |
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| S sulfur 2 P phosphorus 5 O oxygen 2 N nitrogen 3 C carbon 4 H hydrogen 1 |
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| substrate |
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| aka reactants in a chemical reaction |
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| synthesis reaction |
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| -building reaction -involves forming larger molecules -requires energy *endothermic ->most common = dehydration synthesis water molecule is formed by pulling hydrogen and hydroxyl from reactants ->all synthesis reactions in an organism: anabolism |
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| anabolism |
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| all synthesis reactions |
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| decomposition reaction |
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| -breakdown reaction -breaks bonds within larger molecules to form smaller atoms, ions, and molecules -releases energy *exothermic ->most common = hydrolysis ionic components of water are added to the reactants in order to break the bonds -> all decomposition reactions = catabolism |
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| catabolism |
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| all decomposition reactions |
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| metabolism |
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| sum of all chemical reactions in an organism |
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| water |
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| -most abundant substance in organisms -most of it special characteristics is due to two polar covalent bonds -cohesive molecules-surface tension -excellent solvent -remains liquid across wide range of temperatures -participates in many chemical reactions -capillary action due to cohesiveness -ice: hydrogen bonds lock into place |
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| acid |
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| dissociated by water into one or more H+ and one or more anions *0-7 pH acidic |
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| base |
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| binds with H+ ions when dissolved into water; some dissociate into cations and OH- *7-14 on pH scale aka alkaline |
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| pH scale |
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| concentration of H+ in solution ->each decrease in pH number = 10x increase of H+ concentration below 7= acidic 7= neutral above 7= alkaline |
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| salts |
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| compounds that dissociate in water into cations and anions OTHER THAN H+ & OH- |
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| electrolytes |
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| cations and anions of salts -create electrical differences between the inside and outside of cell -transfers electrons from one location to another |
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| functional groups |
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| -contain carbon and hydrogen atoms -atoms often appear in certain common arrangements |
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| monomers |
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| basic building blocks of macromolecules |
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| HYDROXYL |
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| -OH alcohols: names usually end in -ol |
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| CARBONYL |
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| -C=0 | -ketones if the carbonyl croup is within carbon skeleton -adlehydes if carbonyl group is at the end of the carbon skeleton |
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| CARBOXYL |
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| -C=O | OH -acid. carboxylic acid. -H breaks off-> H+ ions= acidic sol'n |
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| AMINE/AMINO |
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| H / -N H absorbs another H+ taking H+ ions= basic solution |
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| SULFHYDRYL |
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| -SH thiols two sulfhydryl groups can interact to help stabilize protein structures |
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| PHOSPHATE |
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| O O || || ~ O-P-O- or ~ O-P-O-H | | O- O | H organic phosphates |
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| lipids |
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| one common trait: hydrophobic -> linked by nonpolar covalent bonds four groups: fats, lipids, waxes, steroids |
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| fats |
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| triglyceride= glycerol + 3 fatty acids C H O P *major role in organisms is to store energy saturated- if every carbon atom is covalently linked to 2 hydrogen atoms. solid at room temp. unsaturated- at least one double bond between two adjacent carbon atoms. kinked structure. liquid at room temp. |
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| phospholipids |
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| =glycerol + 2 fatty acids + phosphate *usually make up bilayer membranes -fatty acid tails are hydrophobic -phosholipid head is polar, thus hydrophillic |
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| wax |
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| contain one long chain of fatty acid covalently linked to long chain alcohol by ester bond -completely insoluble in water: lack the hydrophilic head -Mycobacterium uses waxes. ie, TB & leprosy |
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| steroid |
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| -have 4 fused carbon rings -hydrophobic -hormones -passes straight through membranes |
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| carbohydrates |
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| C H O or (CH2O)n functions: -long term storage of chemical energy -ready energy source -part of backbones of nucleic acids -converted to amino acids -form cell walls -involved in intracellular interactions between animal cells -animal stores=glycogen -plant stores=starch -plant cell walls= cellulose ->glucose is the monomer |
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| monosaccharides |
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| monomers of carbohydrates -glucose -fructose -N-acetyl glucosamine |
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| disaccharide |
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| glucose + fructose = sucrose also: lactose and maltose |
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| polysaccharides |
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| polymers of carbohydrates -starch -cellulose -glycogen -peptidoglycan |
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| proteins |
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| C H O N S primary functions: -structure -enzymatic catalysis -regulation -transportation -defense & offense |
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| amino acids |
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| monomers of proteins amino(NH2)+carboxyl(-OOH)+R H H O | // N - C - C / | H R OH most organisms use 20-21 different amino acids |
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| peptide bonds |
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| by a dehydration synthesis reaction, a covalent bond is formed between the carbon of the carboxyl group of one amino acid and the nitrogen of the amine group of another amino acid in the chain |
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| protein structure |
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| -primary: sequence of amino acids -secondary: ionic bonds, hydrogen bonds, and hydrophobic/hydrophilic characteristics cause many polypeptide chains to fold in coils (alpha helices or beta pleated sheets) -tertiary: further folding into complex 3-D structures that are not repetitive like helices or pleated sheets "globular folding" -quarternary: 2 or more polypeptide chains linked together by disulfide bridges or other bonds |
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| denaturation |
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| process by which a protein's 3-D structure is altered, eliminating its function common causes: heat, pH changes, salt concentration |
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| nucleotides |
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| structure has 3 parts: 1. phosphate (PO4) 2. pentose sugar (deoxyribose or ribose) 3. one of 5 cyclic nitrogenous bases ppp-C5 O / C4 C1->nitrogenous base | | C3_____C2 / covalent H (in DNA) bond or OH (in RNA) |
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| nitrogenous bases |
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| -purines are double ringed: adenosine(A) & guanine(G) -pyridimines are single ringed: cytosine(C), thymine(T) & uracil(U) thymine=DNA only uracil= RNA only C::G & A::T or A::U |
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| nucleic acids |
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| -polymers of nucleotides -linked by covalent bonds between the phosphate group of one nucleotide and the sugar of another |
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| ATP |
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| -nucleotide with 3 phosphate groups -principle, short-term energy supply for cells -the phosphate-phosphate bonds of ATP are called high energy bonds |
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| Carl Woese (domains of life) |
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| archea, bacteria, eukarya |
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| overview of prokaryotic cells |
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| -lack nucleus -lack phospholipid membrane bound structures -small: 1 micrometer in diameter -simple structure -includes bacteria & archea |
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| overview of eukaryotic cells |
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| -have a nucleus -have internal membrane bound organelles -are larger at about 10-100 micrometers in diameter -more complex structure -includes algae, protozoa, fungi, animals and plant cells |
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| Schwann & Schleiden |
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| in the 1800s: composed the theory that all living organisms are composed of cells |
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| glycocalyx |
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| -gelatinous, sticky substance that surrounds the outside of the cell -literally means sugar cup -composed of polysaccharides, polypeptides, or both **both prokaryotic and eukaryotic 2 types: capsule- organized repeating units of organic chemicals, firmly attached to the surface of bacterium slime layer- loosely attached to the cell, water soluble |
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| capsule |
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| type of glycocalyx -organized repeating units of organic chemicals -firmly attached to surface of bacterium -may prevent bacteria from being recognized & destroyed by host |
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| slime layer |
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| type of glycocalyx -loosely attached to the cell -water soluble -sticky layer allows prokaryotes to attach to surfaces |
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| biofilms |
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| -organized layered systems of bacteria and other microbes attached to a surface -use of pili -bacteria in biofilms behave differently than free floating: turn on genes, communication with other microbes, different abx sensitivities **2/3 of all infections are biofilms ->also can be beneficial when used in waste treatment systems |
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| flagella (prokaryotic) |
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| -flagella are not present on ALL prokaryotes -responsible for movement -composed of protein: flagellin -3 parts: filament, hook, basal body ->note that gram + has single pair of rings while gram- has 2 pairs of rings -runs= counterclockwise rotation -tumble= clockwise rotation |
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| flagella arrangements |
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| -monotrichous: one flagella -lophotrichous: small tuft at one end -amphitrichous: both ends -peritrichous: surrounds entire cell -endoflagella: found in spirochetes, flagella forms axial filaments which surrounds the cell |
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| taxis |
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| cell movement that occurs as a positive or negative response to light (phototaxis) or chemicals (chemotaxis) -positive: toward stimuli, more runs -negative: away from stimuli, more tumbles |
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| fimbriae |
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| -sticky, bristle like projections that bacteria use to adhere to one another and substances in their environment -fimbriae can be used for motion like pulling a rope, extension and contraction -also allows for electrical signals in biofilms -special type of fimbriae= pili **note that prokaryotes do not have cilia |
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| pili |
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| -special type of fimbriae -longer than fimbriae, shorter than flagella -composed of pilin protein -known as conjugation pili (due to mediation of conjugation) |
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| conjugation |
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| -with use of pili, allows for transfer of DNA from one cell to another |
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| prokaryotic cell walls |
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| -provide the structure and shape -protect from osmotic forces -assist some cells in attaching to other ells in eluding animicrobial drugs *bacteria and archae have different cell wall chemistry **this is the target for many antibiotics |
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| bacterial cell wall |
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| -most composed of peptidoglycan -peptidoglycan= regularly alternating sugars NAG & NAM (-glycan) & crossbridges of four amino acids aka tetrapeptides (peptido-) -Gram positive & Gram negative |
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| Gram positive cell walls |
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| -stain purple -1 cell membrane -1 thick exterior cell wall -contains teichoic acids (not found in gram negative cell walls ->some are lipoteichoic acids that anchor peptidoglycan to cell membrane |
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| Gram negative cell walls |
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| -stain pink -composed of cell membrane, thin cell wall & exterior cell membrane -only a thin layer of peptidoglycan -bilayer membrane outside of peptidoglycan contains: phospholipids, proteins, and lipopolysaccharide (LPS) -LPS = endotoxin [very toxic] |
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| archael cell walls |
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| composed of other organic molecules such as polysaccharides or proteins OTHER THAN peptidoglycan -allows archea to live in extreme environments -> gram positive archea stain purple -> gram negative archea stain pink |
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| isotonic |
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| equal solutes -no effect on cells when placed in isotonic solutions |
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| hypertonic |
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| GREATER concentration of solutes "salt sucks" -if cell placed in hypertonic sol'n, osmosis causes water to leave the cell. cell shrinks and shrivels. -animal cells= crenation -plant cells= plasmolysis |
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| hypotonic |
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| LESS concentration of solutes -if cell placed into hypotonic sol'n, water will enter the cell by osmosis. the cell will swell or burst. -RBC's= lysis -plant cells= turgid |
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| osmosis |
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| diffusion of water will move freely across cell membranes water flows from low solutes to high solutes in order to create even ratios of solutes to solvents |
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| facilitated diffusion |
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| still passive diffusion, but requires protein channels to pass through membranes |
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| active transport |
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| requires ATP -utilizes permease proteins -uniport: one direction against gradient -antiport: 2 directions, against gradient -symport: coupled transport |
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| inclusions |
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| -prokaryotic structures found in cytoplams -reserve deposits of starch, lipids, or compounds such as nitrogen, phosphate, or sulfur. also PHB. |
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| endospores |
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| -unique structures produced by some Gram positive bacteria -defensive strategy against unfavorable condtions |
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| prokaryotic ribosomes |
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| -site of protein synthesis -70s ribosomes found in prokaryotes |
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| hami |
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| external archae structures which work like grappling hooks to attach |
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| eukaryotic cell walls |
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| *fungi, algae, plants, and some protozoa have cell walls but no glycocalyx -plant cell wall= cellulose -fungal cell wall= cellulose, chitin, and/or glucomannan -algal cell wall= cellulose, proteins, agar, carrageenan, silicates, algin, calcium carbonate, or a combination |
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| endocytosis |
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| -active transport -manipulation of cytoplasm around the cytoskeleton -membrane extends pseudopodia to surround a substance bringing it into the cell -phagocytosis= food brought into the cell -pinocytosis= only liquid brought into the cell |
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| eukaryotic flagella |
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| -shaft composed of tubulin arranged to microtubules -"9 + 2" arrangement of microtubules in all flagellated eukaryotes -filaments anchored to cell by basal body which has "9+0" arrangement -may be singular or multiple, but generally found at one pole of cell **note: no hook (unlike prokaryotes) **also does not rotate like prokaryotic flagella but undulates rhythmically |
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| cilia |
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| **only a eukaryotic structure -shorter and more numerous than flagella -composed of tubulin in "9 + 2" and "9 + 0" arrangements -coordinated beating propels cells through their environment -or used to move substances past the surface of a cell |
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| eukaryotic ribosomes |
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| 80s ribosomes |
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| eukaryotic cytoskeleton |
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| -anchors organelles -cyoplasmic streaming & movement of organelles -endocytosis & amoeboid action -produces basic shape of the cell **made of.. tubulin microtubules (25nm) microfilaments composed of actin (7nm) and intermediate filaments composed of protein subunits (10nm) |
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| centrioles |
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| -play a role in mitosis, cytokinesis, formation of flagella and cilia -"9 + 0" arrangement of microtubules ->centrosome: region where centrioles are found |
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| nucleus |
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| "control center" -often the largest organelle -contains most of the DNA -semi-liquid portion called nucleoplasm contains chromatin (masses of DNA) -one or more nucleoli present: used for RNA synthesis and ribosomes assembled -surrounded by nuclear dual membrane with pores continuous with the endoplasmic reticulum |
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| golgi body |
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| receives, processes, and packages large molecules for transport |
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| endoplasmic reticulum |
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| *synthesis site -netlike arrangement of flattened, hollowed tubules continuous with nuclear envelope -smooth er: lipid synthesis -rough er: transports proteins produced by ribosomes |
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| lysosomes |
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| contain catabolic enzymes -phagolysosome: phagosome and lysosome fused together |
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| peroxisomes |
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| contain enzymes that degrade poisonous wastes |
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| mitochondria |
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| -two membranes composed of phospholipid bilayer -inner membrane= cristae -produces most of cell's ATP "power house" -interior matrix contains 70s ribosomes and circular molecule DNA |
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| chloroplasts |
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| -light harvesting structures found in photosynthetic eukaryotes -have 2 phospholipid bilayer membranes -has its own DNA + 70s ribosomes ->responsible for photosynthesis stacks= granuma thylakoid= inner membrane stroma= matrix |
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| Endosymbiotic Theory |
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| -eukaryotes formed from union of small aerobic prokaryotes with larger anaerobic prokaryotes -smaller prokaryotes became "internal parasites" -parasites lost ability to live independently -larger cell became dependent upon parasites for aerobic production of ATP -these evolved into mitochondria which still have their own DNA & 70s ribosomes |
