Chapter 4 Flashcards
prokaryote
A cell whose genetic material is not enclosed in a nuclear envelope
eukaryote
A cell having DNA inside a distinct membrane-enclosed nucleus
binary fission
Prokaryotic cell reproduction by division into two daughter cells
coccus
A spherical or ovoid bacterium (plural cocci)
bacillus
Any rod-shaped bacterium (2) When written as a genus (Bacillus) refers to rod-shaped, endospore-forming facultatively anaerobic, gram-positive bacteria (plural bacilli)
spiral
A corkscrew-shaped bacterium with axial filaments
diplococci (singular: diplococcus)
Cocci that divide and remain attached in pairs
streptococci (singular: streptococcus)
(1) Cocci that remain attached in chains after cell division. (2) When written as a genus, refers to gram-positive, catalase-negative bacteria
tetrad
A group of four cocci
sarcina (plural: sarcinae)
(1) A group of eight bacteria that remain in a packet after dividing. (2) When written as a genus, refers to gram-positive, anaerobic cocci
staphylococci (singular: staphylococcus)
Cocci in a grapelike cluster or broad sheet
diplobacilli (singular: diplobacillus)
Rods that divide and remain attached in pairs
streptobacilli (singular: streptobacillus)
Rods that remain attached in chains after cell division
coccobacillus (plural: coccobacilli)
A bacterium that is an oval rod
spirillum (plural: spirilla)
(1) A helical or corkscrew-shaped bacterium. (2) When written as a genus, refers to aerobic, helical bacteria with clumps of polar flagella
vibrio
(1) A curved or comma-shaped bacterium. (2) When written as a genus (Vibrio), a gram-negative, motile, facultatively anaerobic curved rod
spirochete
A corkscrew-shaped bacterium with axial filaments
monomorphic
Having a single shape; most bacteria always present with a genetically determined shape
pleomorphic
Having many shapes, characteristic of certain bacteria
glycocalyx
A gelatinous polymer surrounding a cell
capsule
An outer, viscous covering on some bacteria composed of a polysaccharide or polypeptide
slime layer
A glycocalyx that is unorganized and loosely attached to the cell wall
extracellular polymeric substance (EPS)
A glycocalyx that permits bacteria to attach to various surfaces
flagellum (plural: flagella)
A thin appendage from the surface of a cell; used for cellular locomotion; composed of flagellin in prokaryotic cells, composed of 9 + 2 microtubules in eukaryotic cells
atrichous
bacteria that lack flagella
peritrichous
Having flagella distributed over the entire cell
polar flagella
Having flagella at one or both ends of a cell
monotrichous
Having a single flagellum
lophotrichous
Having two or more flagella at one end of a cell
amphitrichous
Having flagella at both ends of a cell
motility
The ability of an organism to move by itself
taxis
Movement in response to an environmental stimulus
chemotaxis
Movement in response to the presence of a chemical
phototaxis
Movement in response to the presence of light
H antigen
Flagella antigens of enterics, identified by serological testing
serovar
A variation within a species; also called serotype
axial filaments or endoflagella
The structure for motility found in spirochetes; also called endoflagellum
fimbria (plural: fimbriae)
An appendage on a bacterial cell used for attachment
pilus (plural: pili)
An appendage on a bacterial cell used for conjugation and gliding motility
cell wall
The outer covering of most bacterial, fungal, algal, and plant cells; in bacteria, it consists of peptidoglycan
peptidoglycan
The structural molecule of bacterial cell walls consisting of the molecules N-acetylglucosamine, N-acetylmuramic acid, tetrapeptide side chain, and peptide side chain
polypeptides
(1) A chain of amino acids. (2) A group of antibiotics
lipopolysaccharide (LPS)
A molecule consisting of a lipid and a polysaccharide, forming the outer membrane of gram-negative cell walls
porins
A type of protein in the outer membrane of gram-negative cell walls that permits the passage of small molecules
lipid A
A component of the gram-negative outer membrane; endotoxin
mycolic acid
Long-chained, branched fatty acids characteristic of members of the genus Mycobacterium
protoplast
A gram-positive bacterium or plant cell treated to remove the cell wall
L form
Prokaryotic cells that lack a cell wall; can return to walled state
spheroplast
A gram-negative bacterium treated to damage the cell wall, resulting in a spherical cell
osmotic lysis
Rupture of the plasma membrane resulting from movement of water into the cell
plasma (cytoplasmic) membrane
The selectively permeable membrane enclosing the cytoplasm of a cell; the outer layer in animal cells, internal to the cell wall in other organisms
fluid mosaic model
A way of describing the dynamic arrangement of phospholipids and proteins comprising the plasma membrane
selective permeability
The property of a plasma membrane to allow certain molecules and ions to move through the membrane while restricting others
chromatophore
An infolding in the plasma membrane where bacterio-chlorophyll is located in photoautotrophic bacteria; also known as thylakoids
mesosomes
An irregular fold in the plasma membrane of a prokaryotic cell that is in artifact of preparation for microscopy
facilitated diffusion
The movement of a substance across a plasma membrane from an area of higher concentration to an area of lower concentration, mediated by transporter proteins
osmosis
The net movement of solvent molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration
osmotic pressure
The force with which a solvent moves from a solution of lower solute concentration to a solution of higher solute concentration
isotonic solution
A solution in which, after immersion of a cell, osmotic pressure is equal across the cell’s membrane
hypotonic solution
A solution that has a lower concentration of solutes that an isotonic solution
hypertonic solution
A solution that has a higher concentration of solutes than an isotonic solution
active transport
Net movement of a substance across a membrane against a concentration gradient; requires the cell to expend energy
group translocation
In prokaryotes, active transport in which a substance is chemically altered during transport across the plasma membrane
cytoplasm
In a prokaryotic cell, everything inside the plasma membrane; in a eukaryotic cell, everything inside the plasma membrane and external to the nucleus
cytoskeleton
Microfilaments, intermediate filaments, and microtubules that provide support and movement for eukaryotic cytoplasm
nucleoid
The region in a bacterial cell containing the chromosome
plasmid
A small circular DNA molecule that replicates independently of the chromosome
ribosome
The site of protein synthesis in a cell, composed of RNA and protein
inclusion
Material held inside a cell, often consisting of reserve deposits
metachromatic granule
A granule that stores inorganic phosphate and stains red with certain blue dyes; characteristic of Corynebacterium diphtheriae. Collectively known as volutin
volutin
Stored inorganic phosphate in a prokaryotic cell. See also metachromatic granule
gas vacuole
A prokaryotic inclusion for buoyancy compensation
magnetosome
An iron oxide inclusion, produced by some gram-negative bacteria, that acts like a magnet
endospore
A resting structure formed inside some bacteria
sporulation or sporogenesis
The process of spore and endospore formation; also called sporogenesis
germination
The process of starting to grow from a spore or endospore
cilium (plural: cilia)
A relatively short cellular projection from some eukaryotic cells, composed of nine pairs plus two microtubules. See flagellum
microtubules
A hollow tube made of the protein tubulin; the structural unit of eukaryotic flagella and centrioles
glycocalyx
A gelatinous polymer surrounding a cell
endocytosis
The process by which material is moved into a eukaryotic cell
cytosol
The fluid portion of cytoplasm
cytoplasmic streaming
The movement of cytoplasm in a eukaryotic cell
organelle
A membrane-enclosed structure within eukaryotic cells
nucleus
The part of a eykaryotic cell that contains the genetic material
nuclear envelope
The double membrane that separates the nucleus from the cytoplasm in a eukaryotic cell
nuclear pore
An opening in the nuclear envelope through which materials enter and exit the nucleus
nucleolus (plural: nucleoli)
An area in a eukaryotic nucleus where rRNA is synthesized
histone
A protein associated with DNA in eukaryotic chromosomes
chromatin
Threadlike, uncondensed DNA in an interphase eukaryotic cell
chromosome
The structure that carries hereditary information, chromosomes contain genes
endoplasmic reticulum (ER)
A membranous network in eukaryotic cells connecting the plasma membrane with the nuclear membrane
cistern (plural: cisternae)
A flattened membranous sac in endoplasmic reticulum and the Golgi complex
rough ER
Endoplasmic reticulum with ribosomes on its surface
smooth ER
Endoplasmic reticulum without ribosomes
Golgi complex
An organelle involved in the secretion of certain proteins
transport vesicle
Membrane-bound sacs that move proteins from the rough ER to the Golgi complex
transfer vesicles
Membrane-bound sacs that move proteins from the Golgi complex to specific areas in the cell
secretory vesicles
A membrane-enclosed sac produced by the endoplasmic reticulum (ER); transports synthesized material into cytoplasm
storage vesicles
Organelles that form from the Golgi complex; contain proteins made in the rough ER and processed in the Golgi complex
mitochondria
An organelle containing Krebs cycle enzymes and the electron transport chain
crista (plural: cristae)
Folding of the inner membrane of a mitochondrion
matrix
Fluid in mitochondria
chloroplast
The organelle that performs photosynthesis in photoautotrophic eukaryotes
thylakoids
A chlorophyll-containing membrane in a chloroplast. A bacterial thylakoid is also known as a chromatophore
granum (plural: grana)
Stack of thylakoid membrane
peroxisomes
Organelle that oxidizes amino acids. fatty acids, and alcohol
centrosome
Region in a eukaryotic cell consisting of a pericentriolar area (protein fibers) and a pair of centrioles; involved in formation of the mitotic spindle
endosymbiotic theory
A model for the evolution of eukaryotes which states that organelles arose from prokaryotic cells living inside a host prokaryote.
