microbiology

an organism that is too small to be seen clearly  with the naked eye and is often unicellular, or if multicellular, does not exhibit a high degree of differentiation

cells having a type of structure characterized by the lack of a true, membrane-enclosed nucleus. All known members of Archaea and most Bacteria exhibit this type of cell structure; some members of the bacterial phylum Planctomycetes  have a membrane surrounding their genetic material.

are usually single-celled organisms. most have cell walls that contain the structural molecule peptidoglycan . although most bacteria exhibit typical prokaryotic cell sturcture (i.e., they lack a membrane -bound nucleus), a few members of the unusual phylum Plactomycetes have their genetic materia surrounded by a membrane

are distinguished  from bacteria by many features , most notably their distinctive rRNA sequences, lack f peptidoglycan in their cell walls and unique membrane lipids. some have unusual metabolic characteristics,such as  the methanogensm which generate methane  (natural) gas. Many archaea are found in extreme environments , including those with high temperatures ( theromphiles) and high concentrations of salt (extreme halopiles)

includes microoganisms classified as protists or fungi. animals and plants are also placed in this domain

Unicellular and sometimes colonial eukaryotic organism that lack cellular differentiation into tissues. Many chemoorganotrophic protists are referred to as protozoa; many phototrophic protists are referred to as algae

a common term for several unrelated groups of photosynthetic eukaryotic microorganisms lacking multicellular sex organs ( except for the charophytes) and conducting vessels. Most are now considered protists

a common term for a group of related unicellular, chemoorganotrophic protists

common term for the members of the protist taxa Myxogastris and  Dictostelia

a collective name for protists also known as oomycetes. formerly thought to be fungi

achlorophyllous, hetetrophic, spore-bearing eukaryotes which absorptive nutrition ans a walled thallus; sometimes called "true fungi" or Eumcycota

an infectious agent having a simple acellular organization with a protein coat and a nucleic acid genome, lacking independent metabolism and multiplying only within living host cells

an infectious agent that is a single stranded RNA not associated with any proteins; the RNA does not code for any protein and is not translated

subviral infectious agents composed only of DNA or RNA; they may encode some proteins and require a helper virus for their replication

an infectious agent consisting only of protein' prions cause a variety of spongiform encephalopathies such as scrapie in sheep and goats

a protein catalyst with specificity for the reaction catalyzed and its substrates

an RNA molecule with catalytic activity

the theory that protists that the 1st self-replicating molecule was RNA and this led to the evolution of the 1st primitive cell

a phylogentic tree that considers the evolutionary relationships among organism from all 3 domains of life: Bacteria, Archaea and Eukarya

the hypothesis that mitochondria, hydogenosones and chloroplasts arose from bacterial endosymbionts of ancestral eukaryotic cells

a hypothesis that consider the origin of the eukaryotes through the development of the hydrogenosome. it suggest the organelle arose as the result of a endosymbiotic anaerobic bacterium that produced  CO₂ and H₂ as the products of femantation

species of higher organisms are groups on interbreeding or potentially interbreeding natural population that are reproductively  isolated . Archaeal a d bacteria species are often defined as collections of strains that have many stable properties in common and differ significantly from other strains.however, there definition of archaeal and bacterial species

a population of organisms that descends from a single organism or pure culture isolate

the study of organism that are usually too small the be seen with the naked eye. special techniques are require to isolate and grow them

an early belief that living organisms could develop from nonliving matter

criteria for proving the causal relationship between a microorganism and a specific disease

the full set of genes present in a cell or virus; all the genetic material in an organism

the study of the molecular organization of genomes, their information content and rthe gene products they encode

the interdisciplinary field that  manages and analyzes large biologic data sets, including genome and protein sequences

a measure of how much a substance deflects a light ray from a straight path as it passes from one medium (e.g., glass) to another (e.g., air). it is calculated as the ratio of the velocity  of light passing through the  1st medium to that of light passing trough the second medium

the lens closest to the specimen

a microscope that illuminates that specimen directly with bright light and forms a dark image on a darker background

or simply condenser is mounted within or beneath the stage and focuses a cone of light on the slide

also know as the eyepieces

a microscope that retains proper focus when the objectives are changed

the ability of a microscope to separate or distinguish between small objects that are close together

the property of a microscope lens that determines how much light can enter and how great resolution the lens can provide

microscopy in which the specimen is brightly illuminated while the background is dark

a microscope that converts slight differences in refractive index and cell density into easily observed differences in light intentsiy

a light microscope that employs 2 beams of plane polarized light. the beams are combined after passing through the specimen and their interference is used to create the image

the light emitted by a substance when it is irradiated with light of a shorter wavelenght

a microscope that exposes a specimen to light of a specific wavelength and then forms an image from the fluorescent light produced

a fluorescent dye

the process which the internal and external structures of cells and organisms are preserved and fixed in position. 2 methods are commonly used: heat fixation and chemical fixation

same as fixation

same as fixation

a chemical group with double bonds that absorbs visible light and gives a dye its color

a staining procedure that requires only a single dye

a differential staining procedure that divides bacteria into Gram-positive and Gram-negative groups based on their ability to retain crystal violet when decolorized with an organic solvent such as enthanol

staining procedures that divide bacteria into separate groups based on  staining properties

a substance that helps fix dye on or in a cell

a staining procedure that differentiates between bacteria based on their ability to retain dye when washed with an acid alcohol solution

like acid-fast staining, it requires heat to drive the dye into a target, in this case the endospore

a technique that reveals the presence of capsules, a network usually made of polysaccharides that surrounds many bacteria and some fungi

provides taxonomically valuable information about the presence and distribution pattern of flagella on the bacterial and archaeal cells

a microscope in which an image is formed by passing an electron beam through a specimen and focusing the scattered electrons with magnetic lenses

an electron microscope that scans a beam of electrons over the surface of a specimen and forms an image of the surface from the electrons that are emitted by it

a specialized electron microscopy procedure that involves rapid freezing on intact specimens, maintenance of the specimen in a frozen state while being examined and imaging from different angles. the information from each angle is used to create a three-dimensional reconstruction

a microscope used to study surface features by moving a sharp probe over the object's surface(e.g., atomic force and scanning tunneling microscopes)

same as scanning probe microscope

same as scanning probe microscope

a pair of cocci

a rod-shaped bacterium or archaeon

a rod-shaped bacterial cell that is curved to forma commalike shape or an incomplete spiral

a rigid, spiral-shaped bacterium

a flexible, spiral-shaped bacterium with periplasmic flagella

refers to cells or viruses that are variable in shape and lack a single, characteristic form

a mass of branching hyphae found in fungi and some bactera

the plasma membrane plus all other external layers

the selectively permeable membrane surrounding  the cell's cytoplasm; also called the cell membrane, plasmalemma, or cytoplasmic membrane. for most cells it is lipid bilayer ( some archaea have a lipid monolayer) with proteins embedded in it (integral proteins) and associated with the surface (peripheral proteins)

the model of cell membranes in which the membrane is a lipid bilayer with intregral proteins buried in the lipid and peripheral proteins more loosely attached to the membrane surface

term describing a molecule that has both hydrophohilic and hydrophobic regions (e.g., phospholipids

polar substance that has a strong affinity of water ( or is readily soluble in water)

a nonpolar substance lacking affinity for water  ( or which is not readily soluble in water)

the selectively permeable membrane surrounding  the cell's cytoplasm; also called the cell membrane, plasmalemma, or cytoplasmic membrane. for most cells it is lipid bilayer ( some archaea have a lipid monolayer) with proteins embedded in it (integral proteins) and associated with the surface (peripheral proteins)

same as plasma membrane

lipids found in bacterial membranes that are similar in structure and function to the sterols found in eukaroytic membranes

a nutrient that is required in relatively large amounts (e.g., carbon and nitrogen)

nutrients such as zine , manganese and copper that are required in very small quantities for growth and reproduction also called trace elements

same as micronutrients

organic compounds that must be supplied in the diet for growth because they are essential cell components or precursors of such components and cannot be synthesized by the organism

the process in which molecules move from a region of higher concentration to one of lower consentration as a result of random thermal agitation

diffusion across the plasma membrane that is aided by a channel protein or carrier protein

the transport of  solute molecules across a membrane against a gradient; it requires a carrier protein and the input of energy.3 major types are primary active transport, which uses hydrolysis of ATP to power transport; secondary active transport, which uses ion gradients across a membrane to power active transport; and group translocation

same as active transport

carrier proteins that move a single solute across a membrane

transport system that uses ATP hydrolysis to drive translocation across the plasma membrane , can be used for nutrient uptake  (ABC importer) or export of substance  (ABC exporter ) including protein secretion

same as active transport

linked transport of 2 substances in the same direction

coupled transport of 2 molecules in which 1 molecule enters the cell as the other leaves the cell

a transport process in which a molecule is moved across a membrane by carrier proteins while being chemically altered at the same time (e.g., phosphoenolpyruvate: sugar phosphotransferase system)

an import group translocation system used by many bacteria. as a sugar is transported into the cell, hydrolysis of a high-energy phosphate bond fuels it import, and sugar is modified by the covalent attachment of the phosphoryl group

a set of proteins involved in the transfer of phosphate from one protein in the set to another. it is often used to regulate protein activity or transcription

a small molecule that complexes with ferric iorn and supplies it to the cell by aiding in it transport across the plasma membrane

a large polymer composed of long chains of altering N-acetlyglucosamine and N-acetymuramic acid residues. the polysaccharide chains are linked to each other through connection between tetrapeptide chains attached to the N-acetymuramic  acids. it provides much of the strength and rigidity possessed by bacterial cell walls; also called murein

a membrane located outside the peptidoglycan layer in the cell walls of typical Gram-negative bacteria

the space between the plasma membrane and the outer membrane in typical Gram-negative bacteria, and  between the plasma membrane and the cell wall in typical Gram-positive bacteria. a similar space is sometimes observed between the plasma membrane and the cell wall of some bacteria

a peptide chain that connects the tetrapeptide chains in the peptidoglycan of some bacteria

polymer of glycerol  or ribitol joined by phosphates; they are found in the cell walls of typical Gram-positive bacteria

a molecule containing both lipid and polysaccharide, which is important in the outer membrane of the typical Gram-negative cell wall. in many bacteria ,it consists of 3 components: lipid A, core polysacchride and o antigen