Micro Exam One

unicellular microorganism that lacks a nucleus and membrane-bound organelles; much small than eukaryotes; live everywhere, even in extreme environments; reproduce asexually

any organism made up of cells containing a nucleus composed of genetic material surrounded by a distinct membrane

a microorganism capable of causing disease

the use of heat to kill pathogens and reduce the number of spoilage microorganisms in food and beverage

the use of microbes or their toxins to terrorize human populations

Vaccines/medicines; Fermentation; Decomposition/fertilizer; Algae/Food supply; Digestion; Infections

observed microbes and introduced most types of microorganisms to the world; "Father of bacteriology and protozoology"

investigated spontaneous generation which led to scientific method; also developed pasteurization

proved that bacteria can cause disease; developed technique of agar colonization; established Koch's Postulates to prove the cause of an infectious disease

developed a staining technique to distinguish between different bacteria

unicellular eukaryotes; nutrition and cell structure similar to animals; liquid habitat; most reproduce asexually, some sexually

eukaryotes; saprophytic (obtain nutrition from dead organisms); rigid cell walls; [molds, yeasts]

unicellular or multicellular; photosynthetic; live in fresh and salt water; sexual or asexual reproduction

hypothesis formed by Pasteur that microorganisms are responsible for disease

• 1. Suspected causative agent must be found in every case and absent from healthy hosts
• 2. Agent must be isolated and grown outside of the host
• 3. When introduced to healthy host, host must get disease
• 4. Same agent must be found in diseased experimental host

type of bond in which there is unequal sharing of electrons between atoms with opposite electrical charges

type of chemical bond in which there is equal sharing of electrons between atoms which have similar electronegativities

a type of bond formed from the attraction of opposite electric charges; electrons are not shared

the electrical attraction between a partially charged hydrogen atom and a full or partial negative charge on a different region of the same molecule or another molecule

compound that dissociates into one or more hydrogen ions and one or more anions

molecule that bonds with hydrogen ions when dissolved in water

a crystalline compound formed by ionic bonding of metallic with nonmetallic elements

a substance, such as protein, that prevents drastic changes in pH.

concentration of hydrogen ions in a solution

an arrangement of atoms common to all members of a class of organic molecules

process by which a protein's 3-D structure is altered, eliminating function

the primary short-term, recyclable energy molecule feuling cellular reactions

stabilize the 3-D shapes of large molecules which is critical for the functioning of enzymes, antibodies, intercellular chemical messengers, and the recognition of target cells by pathogens; also weak bonds, so they can be overcome easily if necessary

• 1. Water molecules are cohesive, generating surface tension, which allows dissolved material to transport into and out of a cell
• 2. Water is a solvent, dissolving electrically charged molecules easily
• 3. Water can remain liquid over a whide range of temperatures
• 4. Water can absorb significant amounts of heat energy without changing temperature; when heated, molecules evaporate and take much of the energy with them
• 5. Water molecules participate in many chemical reactions including hydrolysis and dehydration synthesis

fluctuations outside of these ranges inhibit metabolism and may cause fatalities; too hot = denaturation, too cold = no growth

• Lipids - fats, phosopholipids, waxes, steroids
• Carbohydrates - starch, glycogen, glucose, fructose
• Protein - glycoproteins, lipoproteins, nucleoproteins
• Nucleic acids - DNA, RNA

contain two fatty acid chains and a phophate functional group; "head" of phospholipid is hydrophilic, "tail" is hydrophobic; bilayers compose the outer membranes of all cells and the inner membranes of plant, fungal, and animal cells

steroids with an -OH functional group that interfere with the tight packing of fatty acid chains of phospholipids keeping the membranes fluid and flexible at low temperatures

Large carbs are used for long-term storage of chemical energy, while smaller carbs serve as a ready energy source in most cells; also form part of the DNA and RNA backbones; other carbs are converted into amino acids; polymers of carbs form cell walls and are involved in intercellular interactions between animal cells

Function as structural components, enzymatic catalysts, cell function regulators, substance transporters, and defense/offense mechanisms; primary structure-sequence of amino acids, can vary in length and sequence; tertiary structure-consists of the 3-D shape designed to complete its function; denaturation occurs when the 3-D structure is disrupted by heat, change in pH, or salt concentration

Nucleotides consist of phosphate, a pentose sugar, and one 5 cyclic ring of nitrogenous bases; DNA=deoxyribose, A,G,C,T, no hydroxyl group; RNA=ribose, A,G,C,U, hydroxyl group

Composed of three phosphate groups and is the principle, short-term, recyclable energy supply for cells; when phosphate bonds are broken, energy is released and ATP is converted to ADP; energy from ATP can be used for synthesis reactions, locomotion, and transportation of substances into and out of cells

glycocalyx composed of repeating units of organic chemicals firmly attached to the cell surface

long, whiplike structures protruding from a cell

sticky, proteinaceous extensionsof some bacterial cells that function to adhere cells to one another and to environmental surfaces

tubules involved in bacterial conjugation

in most cells, structural boundary composed of polysaccharide or protein chains that provides shape and support against osmotic pressure

prokaryotic cell having a thick peptidoglycan wall containing teichoic acids; appears purple in Gram-Stain

prokaryotic cell having a wall composed of a thin layer of peptidoglycan, an external membrane, and a perimplasmic space between; appears pink on Gram-stain

potentially fatal toxin released from cell wall of dead and dying Gram-negative bacteria

membrane surrounding all cells and composed of a fluid mosaic of phospholipids and proteins

diffusion of water molecules across a selectively permeable membrane

characteristic of a solution having the same concentration of solutes and water as another

solution having a higher concentration of solutes than another; causes cells to shrink

solution having a lower concentration of solutes than another; causes cells to swell and sometimes burst

nonmembranous organelle found in prokaryotes and eukaryotes, composed of protein and ribosomal RNA and functions to make polypeptides

spherical to ovoid membranous organelle containing a eukaryotic cell's primary genetic material

netlike arrangement of hollow tubules continuous with the outer membrane of the nuclear envelope and functioning as a transport system

in eukaryotic cells, a series of flattened, hollow sacs surrounded by phospholipid bilayers and functioning to package large molecules for export in secretory vesicles

vesicle in animal cells that contains digestive enzymes

spherical to elongated structures found in most eukaryotic cells that produce most of the ATP in the cell

light-harvesting organelle found in photosynthetic eukaryotes

proposal that eukaryotes were formed from the phagocytosis of small prokaryotes by larger prokaryotes, forming organelles

• prokaryotes=no membrane-bound organelles, smaller
• eukaryotes=membrane-bound organelles, larger & more complex

glycocalyx composed of organized repeating units of organic chemicals firmly attached to the cell surface; help protect cells from drying out, may prevent bacteria from being recognized or devoured by defensive cells of the host

fibriae are stikcy, bristle-like projections that help bacteria stick to one another and substances in the environment; pili mediate the transfer of DNA from one cell to another by conjugation; both are shorter than flagella which functions in locomotion

Gram-positive bacterial cell walls have a thick layer of peptidoglycan and teichoic acids, a negative charge, and a purple color; gram-negative bacterial cell walls have a thin layer of peptidoglycan, phospholipids, proteins, and lipopolysaccharides, and appear pink

found in outer cell wall of Gram-negative cells; toxic component is known as LPS or Lipid A; may cause septic shock

made up of phospholipid bilayer composed of lipids and proteins; selectively permeable, proteins transport substances across it, and it helps maintain a concentration and electrical gradient; in photosynthetic bacteria, also harvests light energy

osmosis is the diffusion of water across a selectively permeable membrane; in isotonic solutions neither side of the membrane will experience a net gain or loss of water, in hypertonic solutions cells will lose water and shrivel, in hypotonic solutions cells will take in water and expand, sometimes causing it to burst in animal cells, however plant and bacterial cells have a cell wall to prevent this