Unit 4 4.2 Prokaryotic cells do not have a nucleus
flagella
some cells swim by using appendages called __________, which sometimes look like tiny corkscrews
T
the capsule is not essential to prokaryotic life T/F
ribosomes
complexes of RNA and proteins. Sites of protein synthesis, where the information encoded by the nucleic acids directs the sequential linking of amino acids to form proteins
peptidoglycan
the cell walls of most bacteria, but not those of archaea, contain ___________, a polymer of a carbohydrate that is linked at regular intervals to short peptides. cross linking of these peptides results in a single giant molecule that surrounds the entire cell
cytoskeleton
the collective name for filaments made up of polymers of monomer subunits that play roles in cell division or in maintaining the shapes of cells
shape
the rigidity of the cell wall supports the cell and determine the _________
constant motion
the substances in the cytoplasm are in
permeable
unlike the cell membrane, the outer membrane is relatively ____________, allowing the movement of molecules across it
Nucleoid
a region in the prokaryotic cell where the DNA is located. DNA is hereditary material that controls cell growth, maintenance and repair
attack; drying; attach
capsules help protect the bacteria from _________ by the white blood cells in the animals they infect, keep cells from _________ out, and sometimes help bacteria _________ to other cells
prokaryote structure
cell membrane encloses cell, separating its interior from the external environment, and regulates the traffic of materials into and out of the cell
cytosol
consists of mainly water containing dissolved ions, small molecules, and soluble macromolecules such as proteins
capsule
enclosing the cell wall of some bacteria is a slimy layer composed of most polysaccharides, referred to as the ________________
bacteria
in some ____________, another layer, the outer membrane, encloses the peptidoglycan layer
cell membranes, cytoplasm, ribosomes
like prokaryotic cells, eukaryotic cells have a ________ ____________, _____________, and _____________
cell wall
most prokaryotes have a _______ _______ located outside the cell membrane
cytoplasm
rest of material inside a prokaryotic cell. Consists of a liquid component, the cytosol, and a variety of insoluble filaments and particles, the most abundant of which are ribosomes
internal membrane
some groups of bacteria carry out photosynthesis. these bacteria have an __________ ____________ system that contains molecules needed for photosynthesis