Chapter 4 Flashcards
Lipid bilayer that encloses the cytoplasm of bacterial cells
cytoplasmic (cell) membrane
A circular body in bacteria that contains the primary genetic material
bacterial chromosomes or nucleoid
A bilobed macromolecular complex of ribonucleoprotein that coordinates the codons of mRNA with tRNA anticodons and, in so doing, constitutes the peptide assembly site.
ribosome
Dense fluid encased by the cell membrane; the site of many of the cell’s biochemical and synthetic activities
cytoplasm
A small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell
endospore
A complex association that arises from a mixture of microorganisms growing together on the surface of a habitat
biofilm
Term referring to microbes that are free-floating in a liquid medium
planktonic
A spherical-shaped bacterial cell
coccus
One of the basic shapes of bacteria
coccus (round), rod (bacillus), or curved
One of the basic shapes of bacteria
coccus (round), rod (bacillus), or curved
Groups of four
tetrads
A cubical packet of 8, 16, or more cells
sarcina
Accessory structures that sprout from the surface of bacteria. They can be divided into two major groups: those that provide motility and those that enable adhesion
appendages
A structure that is used to propel the organism through a fluid environment
flagellum
Self-propulsion
motility
A helical structure composed of proteins that is part of bacterial flagella
filament
Term to describe a molecule with an asymmetrical distribution of charges. Such a molecule has a negative pole and a positive pole
polar
Describing a microorganism that bears a single flagellum
monotrichous
Describing bacteria having a tuft of flagella at one or both poles
lophotrichous
Having a single flagellum or a tuft of flagella at opposite poles of a microbial cell
amphitrichous
In bacterial morphology, having flagella distributed over the entire cell
peritrichous
The tendency of organisms to move in response to a chemical gradient (toward an attractant or to avoid adverse stimuli)
chemotaxis
Bacteria moving towards a stimulus in a straight line
run
The way that bacteria move when they are not attracted to a substance
tumble
The movement of organisms in response to light
phototaxis
A type of flagellum (called an endoflagellum) that lies in the periplasmic space of spirochetes and is responsible for locomotion.
axial filaments or periplasmic flagellum
Long, tubular structures made of pilin protein produced by gram-negative bacteria and used for conjugation.
pili (singular pilus)
A short, numerous-surface appendage on some bacteria that provides adhesion but not locomotion
fimbria
A class of protein that makes up bacterial pili
pilin
In bacteria, the contact between donor and recipient cells associated with the transfer of genetic material such as plasmids. Can involve special (sex) pili. Also a form of sexual recombination in ciliated protozoans
conjugation
Single layer of thousands of copies of a single type of protein linked together on the surface of a bacterial cell that is produced when the cell is in a hostile environment
s layer
A filamentous network of carbohydrate-rich molecules that coats cells
glycocalyx
A diffuse, unorganized layer of polysaccharides and/or proteins on the outside of some bacteria
slime layer
In bacteria, the loose, gel-like covering or slime made chiefly of polysaccharides. This layer is protective and can be associated with virulence
capsule
A differential stain for bacteria useful in identification and taxonomy. Gram-positive organisms appear purple from crystal violet mordant retention, whereas gram-negative organisms appear red after loss of crystal violet and absorbance of the safranin counterstain
gram stain
A category of bacterial cells that describes bacteria with a thick cell wall and no outer membrane
gram-positive
A category of bacterial cells that describes bacteria with an outer membrane, a cytoplasmic membrane, and a thin cell wall
gram-negative
In bacteria, a rigid structure made of peptidoglycan that lies just outside the cytoplasmic membrane;
cell wall
A network of polysaccharide chains cross-linked by short peptides that forms the rigid part of bacterial cell walls. Gram-negative bacteria have a smaller amount of this rigid structure than do gram-positive bacteria
peptidoglycan
A type of carbohydrate or polysaccharide that is combined with another organic molecule such as a lipid or protein; examples include peptidoglycan and glycocalyx
glygan
The physical rupture or deterioration of a cell
lysis
Anionic polymers containing glycerol that appear in the walls of gram-positive bacteria
teichoic acid
lipoteichoic acid
A thick, waxy, long-chain fatty acid found in the cell wall of Mycobacterium and Nocardia that confers resistance to chemicals and dyes
mycolic acid
A solution containing carbol fuchsin, which, when bound to lipids in the envelopes of Mycobacterium species, cannot be removed with an acid wash
acid-fast stain
Normal variability of cell shapes in a single species
pleomorphism
V
cell membrane
Lipid bilayer that encloses the cytoplasm of bacterial cells
cytoplasmic membrane
The passage of nutrients across a membrane
transport
Describes a property of cell membranes in which certain substances are able to pass through the membrane, while other substances cannot pass through unaided and require special carrier proteins in order to enter or exit the cell
selectively permeable
An additional membrane possessed by gram-negative bacteria; a lipid bilayer containing specialized proteins and polysaccharides. It lies outside of the cell wall
outer membrane
A molecular complex of lipid and carbohydrate found in the bacterial cell wall.
lipopolysaccharide
A bacterial toxin that is not ordinarily released (as is exotoxin). Endotoxin is composed of a phospholipid-polysaccharide complex that is an integral part of gram-negative bacterial cell walls. Endotoxins can cause severe shock and fever
endotoxin
Transmembrane protein of the outer membrane of gram-negative cells that permits transport of small molecules into the periplasmic space but bars the penetration of larger molecules
porin
Dense fluid encased by the cell membrane; the site of many of the cell’s biochemical and synthetic activities
cytoplasm
A circular body in bacteria that contains the primary genetic material.
bacterial chromosome
The basophilic nuclear region or nuclear body that contains the bacterial chromosome
nucleoid
Extrachromosomal genetic units characterized by several features. It is is a double-stranded DNA that is smaller than and replicates independently of the cell chromosome; it bears genes that are not essential for cell growth; it can bear genes that code for adaptive traits; and it is transmissible to other bacteria
plasmids
A bilobed macromolecular complex of ribonucleoprotein that coordinates the codons of mRNA with tRNA anticodons and, in so doing, constitutes the peptide assembly site
ribosome
A relatively inert body in the cytoplasm such as storage granules, glycogen, fat, or some other aggregated metabolic product
inclusion bodies or inclusions
A type of inclusion in storage compartments of some bacteria that stain a contrasting color when treated with colored dyes
metachromatic granules
Protein component of long filaments of protein arranged under the cell membrane of bacteria; contributes to cell shape and division
actin
A small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell. The bacterial genera Bacillus and Clostridium are typical sporeformers
endospore
The process of spore formation
sporulation
dipicolinic acid
An organic acid found in the walls of endospores; contributes to their extreme resistance to chemicals, drying, and heat
dipicolinic acid
A fungal cell in which asexual spores are formed by multiple cell cleavage
sporangium
Prokaryotic single-celled organisms of primitive origin that have unusual anatomy, physiology, and genetics and live in harsh habitats
archaea
Methane producers
methanogens
A microorganism that thrives at low temperature (0°C–20°C), with a temperature optimum of 0°C–15°C
psychrophile
An organism whose optimal growth temperature is above 80°C (176°F), with a temperature range from 60°C to 113°C (140°F to 235°F)
hyperthermophile
The observable characteristics of an organism produced by the interaction between its genetic potential (genotype) and the environment.
phenotype
Taxonomic category of bacteria that have gram-negative envelopes
Gracilicutes
Taxonomic category of bacteria that have gram-positive cell envelopes
Firmicutes
Taxonomic category of bacteria that lack cell walls
Tenericutes
Taxonomic category of bacteria that have unusual cell walls; archaea
Mendosicutes
A microorganism that lives and grows in the presence of free gaseous oxygen (O2)
aerobe
A microorganism that grows best, or exclusively, in the absence of oxygen.
anaerobe
Pertaining to the capacity of microbes to adapt or adjust to variations; not obligate. Example: the presence of oxygen is not obligatory for a facultative anaerobe to grow. See obligate
facultative
Bacteria of the same species that have differing characteristics; also known as a bacterial type
subspecies
In microbiology, a set of descendants cloned from a common ancestor that retain the original characteristics. Any deviation from the original is a different strain
strain
The subdivision of a species or subspecies into an immunologic type, based upon antigenic characteristics
serotyping
