How can we help?

You can also find more resources in our Help Center.

66 terms

Chapter 4

STUDY
PLAY
Anthrax toxin
A powerful cytotoxin produced by Bacillus anthracis, which increases vascular permeability. It has three components: edema factor, protective antigen, and lethal factor.
Bacillus (plural bacilli)
A rod-shaped organism.
Biofilm
A structure composed of a variety of bacterial species that coexist. It is often seen as the beginning layer of plaque, which builds up on teeth.
Black death
Also known as pneumonic plague and bubonic plague. A noncontagious form of plague caused by Yersinia pestis and transmitted to humans by the bite of a flea. It is a systemic disease that spreads through the blood and lymph fluid.
Botulinum toxin
An extremely poisonous neurotoxin associated with botulism, a digestive intoxication resulting from food poisoning.
Capsule stain
Also known as a negative stain; the background is stained, making the capsule visible.
Capsule
A protective structure found around the outside of a bacterial cell. It can be made up of polysaccharides, polypeptides, or a combination of both.
Cholera toxin
An exotoxin produced by Vibrio cholera pathogens. It is an enterotoxin that causes increased permeability in the intestinal tract and a consequent loss of fluids.
Chromatin
The form of DNA seen in cells that are not ready to divide. It has the appearance of threads.
Chromosome
The structure containing DNA that is seen in cells that are ready to divide. It is derived from the condensation of chromatin.
Cilia (singular cilium)
Short cellular projections seen in eukaryotic cells used for movement that result from the beating of these projections in coordinated waves.
Coccus (plural cocci)
A spherical bacterium.
Cytoplasm
The semifluid substance inside cells, excluding the nucleus of eukaryotic cells.
Dental plaque
Adherent deposits that form as a result of bacterial colonization of the surface of the teeth.
Differential stain
The use of two or more dyes to differentiate between bacterial species or distinguish different structures of an organism.
Diphtheria toxin
An exotoxin produced by Corynebacterium diphtheriae that affects the membranes of the nose, throat, and larynx. It can also affect the heart and the central nervous system.
Diphtheria
An acute bacterial infection of the nose, throat, or larynx caused by Corynebacterium diphtheriae. It is marked by formation of a grey/white pseudomembrane.
Diplococcus (plural diplococci)
The arrangement of bacteria that grow in pairs. Streptococcus pneumoniae, the leading cause of pneumonia, is an important example.
Endocytosis
The process in which vesicles form by invagination of the plasma membrane of the cell and move substances into the cell.
Endoplasmic reticulum
An extensive network of membranes that form tubes and plates in the cytoplasm of eukaryotic cells. They are involved in the synthesis and transport of proteins and lipids.
Endospore
A highly resistant dormant structure that is formed by certain bacteria.
Endosymbiotic theory
Evolutionary theory holding that the organelles of eukaryotic cells arose from bacteria that came to live in a symbiotic relationship inside eucaryotic cells.
Eukaryote
A cell that has a distinct nucleus and other membrane-enclosed organelles.
Exocytosis
Process in which vesicles inside a cell fuse with the plasma membrane and release their contents to the outside of the cell.
Flagella stain
A technique used for observing flagella by coating the surface of the flagella with multiple layers of dye or metal such as silver.
Golgi apparatus
An organelle found in eukaryotic cells that receives, modifies, and transports substances coming from the endoplasmic reticulum.
Gonorrhea
A sexually transmitted infection caused by Neisseria gonorrhoaea, commonly asymptomatic in females but marked by a painful purulent discharge from the urethra in males.
Gram stain
A differential stain that differentiates bacteria into either Gram-positive or Gram-negative groups.
Helicobacter pylori
An organism found in the stomach and duodenum of the small intestine; it accounts for up to 80% of ulcers found in these regions of the digestive tract.
Latent infection
A disease in which there are periods of inactivity either before the onset of symptoms or between attacks.
Lysosome
A small membrane-enclosed organelle seen in eukaryotic cells that contains digestive enzymes.
Microfilament
A protein fiber that makes up part of the cytoskeleton in eukaryotic cells.
Microtubule
A protein tubule that forms the structure of cilia, flagella, and part of the cytoskeleton in eukaryotic cells.
Mitochondria (singular mitochondrion)
A membrane-enclosed organelle found in eukaryotic cells that is responsible for the production of ATP.
Mumps
An acute contagious disease usually seen in children. It is caused by a paramyxovirus and chiefly affects the parotid salivary glands.
Mutagen
An agent that causes mutations in DNA.
Mutualism (mutualistic)
A form of symbiosis in which two organisms of different species live in a relationship in which both benefit.
Nuclear membrane
Also called the nuclear envelope. It is the membrane surrounding the nucleus seen in eukaryotic cells.
Nucleoli (singular nucleolus)
Areas in the nucleus of eucaryotic cells where ribosomal RNA is made and ribosomal assembly takes place.
Nucleoplasm
The semifluid portion of the cell nucleus of eukaryotic cells that is surrounded by the nuclear membrane.
O polysaccharide
A type of polysaccharide found on the cell wall of bacteria.
Opportunistic pathogen
Resident or transient microorganisms that do not ordinarily cause disease but can do so under certain circumstances.
Organelle
A structure found in the cytoplasm of eukaryotic cells.
Pathogen
An organism capable of causing disease.
Pathogenicity islands
Sections of the genome that include groups of genes coding for virulence factors that increase the pathogenicity of a microorganism.
Peroxisome
Vesicles in eukaryotic cells that contain the enzymes peroxidase, catalase, and oxidase.
Pertussis
A highly contagious respiratory infection caused by Bordetella pertussis. Also known as whooping cough.
Pinocytosis
The taking in of small molecules by invagination of the cell membrane.
Plasmid
An extrachromosomal piece of DNA that is small and circular and replicates independently. It can be transferred to another cell.
Pneumonic plague
Also known as the black death and bubonic plague. An infection of the lungs with Yersinia pestis, causing a highly contagious form of plague.
Prokaryote
Microorganism that lacks a cell nucleus and membrane-enclosed organelles. All bacteria are prokaryotes.
Proteasome
Large proteins found in both prokaryotes and eukaryotes that degrade unneeded or damaged proteins.
Protozoa
Single-celled, microscopic, animal-like organisms.
Quorum sensing
Type of decision-making process seen in bacteria that is based on the density of the population of bacteria.
Receptor-mediated endocytosis
The process of uptake of materials into the cell through binding to specific receptors on the cell membrane.
Simple stain
A single dye used to reveal cell shapes and arrangements.
Spirillum (plural spirilla)
A spiral-shaped rigid bacterium.
Spirochete
A corkscrew-shaped motile bacterium.
Sporogenesis
The development of a spore.
Syphilis
Venereal disease caused by Treponema pallidum leading to many structural and cutaneous lesions.
Tetanus
An acute and often fatal infection caused by the neurotoxin produced by Clostridium tetani.
Ubiquitin
Molecular carrier tags for materials to be taken to the proteasome for recycling.
Vibrio toxin
An enterotoxin that damages the intestinal lining.
Viral envelope
The structure seen around the capsid of some viruses. It is made up of the membrane components obtained when the mature virion leaves the host cell during the process of budding release.
Virulence
The degree of intensity of the disease produced by a pathogen.
Whooping cough
A highly contagious respiratory infection caused by Bordetella pertussis. Also known as pertussis.