Cell Structure and Function: 3 Domains of Life Flashcards
prokaryote
small unicellular organism, such as a bacterium, that lacks internal membrane-bound organelles, including a nucleus
plasma membrane
the phospholipid bilayer that forms the outer boundary of any cell
cell wall
a fairly rigid polysaccharide supportive and protective layer containing peptidoglycan that lies outside the plasma membrane
capsule
a sticky layer that surrounds the cell wall of some prokaryotes, protecting the cell surface
cytoplasm
the contents of the cell enclosed by the plasma membrane, excluding the nucleus
cytosol
the water-based fluid component of the cytoplasm
nucleoid
a dense region of DNA in a prokaryotic cell
ribosome
a particle composed of proteins and RNA at which new proteins are synthesized
flagellum (pl. flagella)
a long cellular extension that rotates, enabling that cell to move (structured differently than eukaryotic flagella)
centrifugation
the process of separating or concentrating particles suspended in a liquid medium by using centrifugal force; can be used to study the functions of subcellular structures
electrophoresis
the process of sorting, identifying, and measuring small molecules such as DNA and proteins by using an electric current to cause the samples to travel down a gel filter
microscopy
a method used to magnify specimens for study; includes light microscopy and electron microscopy
resolution
a measure of the smallest detail that can be distinguished between two objects; resolving power is inversely proportional to the wavelength of the light or other incident beam and places limits on magnification
phylogeny
the evolutionary history of an organism or group of organisms determined through comparisons of modern life forms and structures with fossils
