Study

chapter 7

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  • Why doesn't a negative stain color a cell?
    negative stains are acidic-due to repulsion between the negative charges of the stain and the (-) bacterial surface, the dye will not penetrate the cell.
  • How are flagella stained?
    use mordant on flagella and stain with carbolfuchsin
  • Compare and contrast DNA and RNA differ?
    RNA contains the sugar ribose, DNA deoxyribose, DNA double strand, RNA single, RNA uses uracil, DNA thyamine; they both use Adenine, cytosil and guanine
  • Which can provide more energy for a cell and why: ATP or ADP?
     ATP has 3phosphate molecules and more energy than ADP, which only has 2
  • What two functional groups are in all amino acids?
    amine (–NH2) and carboxylic acid (–COOH) functional groups, linked to the same carbon atom.
  • What type of bond holds together Carbon and oxygen atoms in methanol
    Single covalent
  • Antacids neutralize acid by the following reaction. Mg(OH)2 + 2HCl ® MgCl2 + H2O Identify the acid, base, and salt.
    Mg(OH)=base; HCl=acid; MgCl2=salt
  • Which microscopes give a 3D image of a specimen?
    confocal and electron microscopes
  • give examples of inorganic molecules
    No carbon, structurally simple, water, salts, acids, bases
  • What functional group has a Carbon double bonded to an oxygen at the end of the molecule and reduces sugars
    an aldehyde
  • What are endospores
    resting cells, resistant to desiccation, heat, and chemicals.
  • under what conditions do endospores form?
    harsh environments, form spores around DNA. cell dies off and DNA remains protected. 
  • Give an example of a disacharide
    sucrose= glucose+fructose; lactose=glucose+galactose; maltose=glucose+glucose
  • What type of bond holds A hydrogen atom of one nucleotide to a nitrogen or oxygen atom of another nucleotide in DNA together
    Hydrogen bond
  • What functional group helps build organic acids, proteins and lipids, (COOH)
    carboxyl
  • This chemical reaction below is used to remove chlorine from water. What type of reaction is it? HClO + Na2SO3 ® Na2SO4 + HCl
    Exchange synthesis reaction
  • Define functional group
    specific group of atoms in a molecule responsible for the chemical reactivity and behavior of organic compounds
  • What gives electron microscopy greater resolution?
    shorter wavelengths
  • Give examples of a polysaccharide
    starch cellulose, glycogen
  • When preforming a gram stain you forgot the decolorizing step, what color would gram (+) bacteria be? Gram (-)?
    They would both be purple
  • Identify the building blocks and structure of proteins.
    Amino acids which is a carbon atom linked to an amino group, carboxyl group, H+ atom and a variable group
  • What happens when non acid fast bacteria are stained using acid fast staining technique?
    primary stain makes cells red but the cell walls lack waxy lipid component, is washed away by the decolorization step, then the counterstain makes cells blue
  • What type of bond holds Li+ and Cl- in LiCl together
    ionic
  • using the whiteboard, draw the following functional groups methyl, aldehyde, ketone, phophate, amino
    CH3, COH, CO, PO4, NH2
  • using the whiteboard draw the following functional groups; sulfhydyl, ester, ether, carboxyl
    SH, COO C2OH4, COOH
  • If a reaction is endergonic and anabolic, what type of reaction could it be?
    synthesis reaction
  • What functional group is found in DNA, participates in energy metabolism and is a carbon single bonded to 3 hydrogens
    Methyl
  • What happens when acid fast bacteria are stained?
    primary stain carbolfuchsin is retained during decolorization step because of cell walls waxy lipids, stays red after counterstain of methylene blue
  • What is a basic dye? What is an acidic dye?
    Basic- chromophore is a cation, basic dye (+) charged, is attracted to the (-) charged cell wall; acidic dyes are (-), chromophore is an anion, repels (-) cell
  • What stain would be used to identify mycobacterium and nocardia?
    acid fast
  • What are the building blocks of carbohydrates? 
    carbon,hydrogen,oxygen with hydrogen and oxygen in a 2:1 ratio
  • What is a monomer of sucrose?
    glucose, fructose
  • What is the difference between an Ionic bond and a covalent bond?
    Ionic is losing and gaining electron(s) Covalent is sharing the same electron(s)
  • What dyes are used in an endospore stain? What is the procedure? If endospores are present, how do they appear?
    primary stain of malachite green with heat, decolorize with water, counterstain with safranin, endospores will be green in red cell
  • What color are Gram(-) cells after adding the decolorizer, alcohol acetone? After the counter stain safranin?
    Clear after decolorizer and pink after counterstain
  • What are characteristics of an organic molecule? Give examples
    always contains a carbon! Structurally complex, protiens, nucleic acids, lipids...
  • Explain the steps of the gram stain technique and differentiate between gram-positive and gram-negative cells.
    primary-crystal violet, mordant (iodine), decolorization (alcohol wash), counterstain (safranin) (+) purple (-) pink
  • List several properties of water that are important to living systems.
    ability to act as a universal solvent, cohesion, adhesion,specific heat capacity help support the life processes and habitats of all organisms.
  • Which microscope could you use to view internal structures of live specimens?
    phase-contrast, two-photon, DIC, fluorescence,  and confocal microscopes