Clinical Microbiology Exam 1

microorganisms/microbes

organisms that are too small to be seen with the unaided eye

bacteria, fungi, protozoa, microscopic algae, and viruses

types of microorganisms

biogenesis

the hypothesis that living cells arise only from pre-existing living cells

aseptic technique

methods that prevent microbial contamination

fermentation

the microbial conversion of sugar to alcohol in the absence of air

pasteurization

the application of a high heat for a short time to kill harmful bacteria in beverages

chemotherapy

treatment of disease with chemicals

biotechnology

the use of biological processes for practical applications, such as producing foods and chemicals

pathogenic

disease causing

bacteriology

study of bacteria

mycology

study of fungi

parasitology

study of parasites

virology

study of viruses

microbial genetics

the study of how microbes inherit traits

microbial ecology

the study of the relationship between microorganisms and their environment

immunology

study of the immune system/immunity

molecular biology

the study of how DNA directs protein synthesis

genomics

study of whole genomes, including genes and their functions

pathogens

microbes that can cause disease and that carry out all or part of their life cycle in the infected host

disease

a condition that impairs normal functioning and typically shows distinguishing signs and symptoms

infectious disease

disease caused by pathogens invading a susceptible host

emerging infectious diseases (EIDs)

new diseases and diseases increasing in incidence

biofilm

community of microbes in which the cells stick to each other and usually to a surface; has a protective slime-like outer layer and is often resistant to antibiotics

resistance

the ability to ward off disease

normal microbiota

the microbes normally present in and on a healthy human body

microbiome

all the microorganisms in an environment

compound light microscope

microscope that uses a series of lenses to magnify objects and uses visible light

total magnification

objective lens x ocular lens

refractive index

a measure of the light-bending ability of a medium

resolution

The ability to clearly distinguish the individual parts of an object (details)

staining

coloring the microbe with a dye that emphasizes certain structures

smear

created when a thin film of material containing the microorganisms is spread

fix (fixed)

heat specimens using the flame from a Bunsen burner to attach them to the glass slide and kill them

simple stain

use of a single dye, highlights the entire microorganism to visualize cell shapes and structures (morphology)

morphology

the study of the structure and form of an organism

differential stain

used to distinguish between different species (stain); ex. gram stain

gram stain

A staining method that distinguishes between two different kinds of bacterial cell walls

gram-positive

thick peptidoglycan layer

gram-negative

thin peptidoglycan layer and outer membrane composed of lipopolysaccharide

crystal violet

primary stain in gram stain

iodine

mordant in gram stain

alcohol wash

decolorization in gram stain

safranin

counterstain in gram stain

acid-fast stain

a staining procedure for identifying bacteria that have a waxy cell wall

carbolfuchsin

primary stain in acid fast stain

acid-alcohol

decolorizer in acid-fast stain

methylene blue

counterstain in acid-fast stain

special stains

used to distinguish specific structures of microorganisms

capsule stain (negative stain)

capsule remains unstained and forms a while ring around stained cell and background

capsule

a sticky, gelatinous layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces; contributes to virulence

endospores

a resistant, dormant structure formed inside of some bacteria that can withstand adverse conditions

malachite green

primary stain in endospore stain

water

decolorizer in endospore stain

safranin

counterstain in endospore stain

flagella

structures used for bacterial locomotion

flagella stain

uses a mordant and carbolfuchsin dye to thicken appearance of flagella, making them visible under a light microscope

primary stain

first dye used to color microbes

counterstain

second dye used after a wash step

mordant

substance used to set/bind dye and acts to intensify staining

prokaryotic

one circular chromosome, not in a membrane; no histones; no organelles; peptidoglycan cell walls (bacteria); divide by binary fission, no true nucleus, pseudomurein cell walls (archaea)

bacteria

peptidoglycan cell walls

archaea

pseudomurein cell walls

glycocalyx

viscous and gelatinous polymer made of polysaccharide and/or polypeptide (made inside cell and excreted)

slime layer

unorganized and loosely attached to cell wall, often forms net-like structures between cells

fimbriae

hairlike appendages that allow for attachment (biofilm formation and virulence)

pili

appendages that allow bacteria to attach to each other and to transfer DNA (conjugation _____)

cell wall

complex semi-rigid structure that protects the cell, provides shape, and is an anchorage point for flagella

mycoplasma

only bacteria without a cell wall

lysozyme

an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria (cuts bonds in the peptidoglycan)

plasma membrane

phospholipid bilayer that encloses the cytoplasm; peripheral proteins, integral and transmembrane proteins, selective permeability

passive processes

move from high to low concentration, no energy (general term)

active processes

move from low to high concentration; energy expended (general term)

simple diffusion

molecules move from high to low concentration, a form of passive transport, until molecules reach equilibrium

facilitated diffusion

transport proteins move molecules from areas of high concentration to areas of low concentration (larger molecules or hydrophilic ions)

osmosis

movement of water across the membrane from high to low water concentration

isotonic solution

solute concentrations equal inside and outside of cell; water is at equilibrium

osmotic pressure

the pressure needed to stop the movement of water across the membrane

hypertonic solution

Solute concentration is greater than that inside the cell; cell loses water

hypotonic solution

Solute concentration is less than that inside the cell; cell gains water

osmotic lysis

swelling and bursting of a cell in a hypotonic solution ( cell wall prevents)

active transport

requires a transporter protein; substance is not changed during transport (from low to high)

group translocation

active transport requiring a transporter protein (exclusive to prokaryotes); substance is altered as it crosses the membrane so that it cannot exit again; allows bacteria to stockpile limited resources

cytoplasm

everything inside the plasma membrane

nucleoid

a non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated

bacterial chromosome

circular thread of DNA that contains the cell's genetic information

plasmids

extrachromosomal genetic elements; carry non-crucial genes

ribosomes

site of protein synthesis (70S = 50S + 30 S) in prokaryotes

inclusions

act as reserve deposits for certain nutrients

metachromatic granules (volutin)

phosphate reserves (type of inclusion)

polysaccharide granules

energy reserves (type of inclusion)

sporulation

formation of endospores

eukaryotes

paired chromosomes in nuclear membrane; histones; organelles; polysaccharide cell walls; divides by mitosis

cilia

short, numerous projections that look like hairs

cell wall

found in plants, algae, and fungi; made of carbohydrates; far less complex than in prokaryotes

sterols

complex lipids that provides protection from osmotic lysis

endocytosis

segment of plasma membrane surrounds particle, encloses it, and brings it into the cell

phagocytosis

pseudopods extend and engulf particles

pinocytosis

membrane folds inward, bringing in fluid and dissolved substances

receptor-mediated endocytosis

incoming substances bind receptors on outside of cell to trigger endocytosis

ribosomes

80S = 60S + 40S subunits in eukaryotes