Unit 1 Ch 1 - Exploring the Microbial World Flashcards
from Unit 1 -The Foundations of Microbiology
Aseptic technique
the manipulation of sterile instruments or culture media in such a way as to maintain sterility
Cell wall
a rigid layer present outside the cytoplasmic membrane; it confers structural strength on the cell
Chemolithotrophy
a form of metabolism in which energy is generated from the oxidation of inorganic compounds
Colony
a macroscopically visible population of cells growing on solid medium, arising from a single cell
Contrast
the ability to resolve a cell or structure from its surroundings
Culture
a collection of microbial cells grown using a nutrient medium
Cytoplasm
the fluid portion of a cell, enclosed by the cytoplasmic membrane
Differentiation
modification of cellular components to form a new structure, such as a spore
Domain
one of the three main evolutionary lineages of cells: the Bacteria; the Archaea, and the Eukarya
DNA replication
the process by which information from DNA is copied into a new strand of DNA
Enrichment culture technique
a method for isolating specific microorganisms from nature using specific culture media and incubation conditions
Enzyme
a protein (or in some cases RNA) catalyst that functions to speed up chemical reactions
Eukaryotic
having a membrane-enclosed nucleus and various other membrane-enclosed organelles; cells of Eukarya
Evolution
a change over time in gene sequence and frequency within a population of organisms, resulting in descent with modification
Extremophiles
microorganisms that inhabit environments characterized by extremes of temperature, pH, pressure or salinity
Genome
an organism’s full complement of genes
Gram-negative
a bacterial cell with a cell wall containing small amounts of peptidoglycan and an outer membrane
Gram-positive
a bacterial cell whose cell wall consists chiefly of peptidoglycan; it lacks the outer membrane of gram-negative cells
Gram stain
a differential staining procedure that stains cells either purple (gram-positive) or pink (gram-negative)
Growth
in microbiology, an increase in cell number with time
Gut microbiome
the microbial communities present in the animal gastrointestinal tract
Horizontal gene transfer
the transfer of genes between cells through a process uncoupled from reproduction
Intercellular communication
interactions between cells through a process using chemical signals
Koch’s postulates
a set of criteria for proving that a given microorganism causes a given disease
Macromolecules
a polymer of monomeric units, for example proteins, nucleic acids, polysaccharides and lipids
Medium (plural: media)
in microbiology, the liquid or solid nutrient mixture(s) used to grow microorganisms
Magnification
the optical enlargement of an image
Metabolism
all biochemical reactions in a cell
Microbial community
two or more populations of cells that coexist and interact in a habitat
Microbial ecology
the study of microorganisms in their natural environments
Microorganism
an organism that is too small to be seen by the unaided human eye
Motility
the movement of cells by some form of self-propulsion
Nucleoid
the aggregated mass of DNA that makes up the chromosome(s) of prokaryotic cells
Nucleus
a membrane-enclosed structure in eukaryotic cells that contains the cell’s DNA genome
Organelle
a bilayer-membrane-enclosed structure such as the mitochondrion, found in eukaryotic cells
Pathogen
a disease-causing microorganism
Phylogenetic tree
a diagram that depicts the evolutionary history of organisms
Phylogeny
the evolutionary history of organisms
Plasmid
an extrachromosomal genetic element that is not essential for growth
Prokaryotic
lacking a membrane-enclosed nucleus and other organelles; cells of Bacteria or Archaea
Pure culture
a culture containing a single kind of microorganism
Resolution
the ability to distinguish two objects as distinct and separate when viewed under the microscope
Ribosomes
a structure composed of RNAs and proteins upon which new proteins are made
Ribosomal RNA (rRNA)
the types of RNA found in the ribosome
Spontaneous generation
the hypothesis that living organisms can originate from nonliving matter
Sterile
Free of all living organisms (cells) and viruses
Transcription
the synthesis of an RNA molecule complementary to one of the two strands of a double-stranded DNA moleculeT
Translation
the synthesis of protein by a ribosome using the genetic information in a messenger RNA as a template
