Module 2 Flashcards
Archaeal cells
cells of the domain Archaea, are as variable as bacterial cells in size and shape.
Bacterial cells
cells of the domain Bacteria, come in a limited assortment of shapes
can be classified by whether they tend to remain attached following cell division
Cocci
round
bacilli/rods
tube shaped
spirochetes
corkscrew
spirilla
twisted
stalks
anchor bacteria to solid surfaces
Characteristic conformations
pairs, chains, clusters
Bacteriology
the subdivision of microbiology that studies the morphology, ecology, genetics and biochemistry of bacteria.
Bacteriophages
viruses that infect bacteria cells.
Capsid
a virus coat found as part of a virion
Capsules
a layer external to the cell wall in some bacterial cells. Can serve to protect against desiccation, viruses, and toxic agents
Cell envelope
material that encases the entire cell. This term encompasses the plasma or cytoplasmic membrane, cell wall, and any layers outside the cell wall
Cell wall
essential for almost all bacteria as it helps maintain shape and protects the cell from osmotic lysis.
Chemotaxis
movement in response to chemical gradients.
Cilia
threadlike locomotor appendages extending outward from the plasma membrane and cell wall. Movement occurs in two beats or phases
Cytoplasm
the entire component with the cell membrane of a cell.
Cytoskeleton
within the cytoplasm, it is network of protein filaments that functions like a vast 3-dimensional roadway that facilitates and guides movement of intercellular structures and components. A well-defined cytoskeleton is unique to eukaryotic cells.
Cytosol
the liquid component of the cytoplasm
Endospores
during adverse conditions, certain types of bacteria undergo a sporulation cycle to produce these dormant cells
Eukaryotic cells
cells of the domain Eukarya, known for their morphological diversity and compartmentalization through various organelles
Fimbriae or Pili
synonymous terms for thin, hair-like appendages that stick out from the cell surface, and are used for attachment or motility.
Flagella
threadlike locomotor appendages extending outward from the plasma membrane and cell wall. Movement occurs in a wave from base to tip (or tip to base)
Inclusions
common in all cells, formed by the aggregation of substances that may be organic or inorganic. They can form granules, crystals, or globules or be amorphous in shape. Some inclusion bodies are useful for species identification
Lipid bilayer
term used to describe the makeup of a membrane with two layers of lipid molecules
Lipid monolayer
term used to describe the makeup of a membrane with one layer of lipid molecules.
Lysogenic infection
some prokaryotic viruses have a more complex strategy that gives them the additional option to not immediately proceed through the lytic cycle, but rather can turn off its lytic pathway and remain silent within the infected cell. Once induced, they proceed down a lytic pathway to generate and release new virions.
Lytic infection
when a virus propagates simply by infecting, replicating and bursting from its host cell in repeated cycles
Membrane proteins
various proteins embedded in or associated with the plasma membrane.
Nucleoid
a zone within the cytoplasm where the DNA and numerous proteins resides.
Oncoviruses
animal viruses that can promote their host cells to undergo uncontrolled growth leading to cancer
Outer membrane
An additional membrane structure in the cell wall of Gram negative cells that provides both protections and limitations
Peptidoglycan
also called murein, this is a polymer of sugars and amino acids that forms the bacterial cell wall; synthesis of this layer can be targeted by the penicillin family of antibiotics. All archaeal cell walls lack peptidoglycan
Plasma membrane
functions to encompass the cytoplasm and is a requirement for all living cells.
Plasmid
extrachromosomal (meaning outside the chromosome) DNA molecules
Prions
infectious protein particles comprised of a single protein made by the host organism that has been induced to undergo an alternate conformation
Ribosomes
the cell’s machinery for protein synthesis and nearly each cell has large numbers of them (10,000 to 20,000)
S-layers
a layer external to the cell wall in some bacterial cells. The biological roles for S-layers include protecting the cell against ion and pH fluctuations, osmotic stress, enzymes, or predatory bacteria. It can also help maintain cell shape and rigidity of some cells. It can also protect against host defenses for some pathogens
Satellite viruses/Satellite nucleic acids
infectious agents that are even less complex than a virus; can be described as parasites of other viruses
Slime layer
a layer external to the cell wall in some bacterial cells. A zone of diffuse, unorganized material that is removed easily
Virion
a complete virus particle, the form of the virus that can exist outside the cell and infect new cells
Viroids
infectious agents that are even less complex than a virus; small infectious RNA molecules that are mainly known to cause disease in plants.
Virology
the study of viruses and virus-like agents.
Viruses
infectious agents composed of a nucleic acid genome and, at minimum, a protein coat. They are absolutely dependent on a host cell for their replication
