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