Principles 1- Part B Flashcards
_______ are known to exist in extreme environements
Archea
What are the three domains of life?
Bacteria (true bacteria)
Archaea (also prokaryotic)
Eucarya
some _______ also have internal membrane systems
internal
highly organized, asymmetric, flexible, and
dynamic
Plasma Membrane
– interact with water
– hydrophilic
polar ends
– insoluble in water
– hydrophobic
nonpolar ends
Hopanoid
bacterial version of cholesterol
separation of cell from its environment
• selectively permeable barrier
– some molecules are allowed to pass into or out
of the cell
– transport systems aid in movement of molecules
• location of crucial metabolic processes
• detection of and response to chemicals in surroundings with the aid of special receptor molecules in the membrane
Functions of the Plasma Membrane
granules of organic or inorganic material
that are stockpiled by the cell for future use
Inclusion Bodies
It is very rare for _____ _____ to be encolsed by a single-layered membrane
inclusion bodies
- complex structures consisting of protein and
RNA - sites of protein synthesis
Ribosomes
_______ are different in the prokaryotic and the Eukaryotic forms. This can be seen on the macro level but can be manipulated on the micro level.
ribosomes
irregularly shaped region • location of chromosome – usually 1/cell • not membrane- bound
The Nucleoid
In actively growing cells, the________ has projections; these probably contain DNA being actively transcribed
nucleoid
• a closed circular, double-stranded DNA
molecule
• looped and coiled extensively
• nucleoid proteins probably aid in folding
– nucleoid proteins differ from histones
The prokaryotic chromosome
T or F:
some prokaryotes have more than 1 chromosome. This is considered an unusual nucleoid
true
T or F: some prokaryotes have chromosomes
composed of linear double-stranded DNA
True. this is considered unusual
T or F: a few genera have membrane-delimited
nucleoids
True. this is considered unusual
• usually small, closed circular DNA molecules • exist and replicate independently of chromosome • not required for growth and reproduction • may carry genes that confer selective advantage (e.g., drug resistance)
Plasmids
True or false: Prokaryotes have a cell wall
true
- provides characteristic shape to cell
- protects the cell from osmotic lysis
- may also contribute to pathogenicity
- may also protect cell from toxic substances
Functions of the cell wall
Bacteria are divided into two major groups based on the response to Gram-stain
procedure. the staining reaction due to cell wall structure.
What are the two types of categories?
Gram + and Gram -
t or f: gram-positive bacteria stain purple
true
gram-negative bacteria stain______.
pink
The gram + cell wall has a _____ layer of peptidoglycan .
thick
The gram - cell wall has a _______ layer of peptidoglycan that is separate from the cell wall.
thin
gap between plasma membrane and cell
wall (gram-positive bacteria) or between
plasma membrane and outer membrane
(gram-negative bacteria)
periplasmic space
substance that occupies periplasmic space
periplasm
Where are periplasmic enzymes found?
found in periplasm of gram-negative
bacteria
– nutrient acquisition
– electron transport
– peptidoglycan synthesis
– modification of toxic compounds
Functions of periplasmic enzymes
_____ are secreted by gram-positive bacteria
Exoenzymes
_______ perform many of the same functions that
periplasmic enzymes do for gram-negative
bacteria
Exoenzymes
______ ______ is a important component of both gram-positive
and gram-negative bacteria
peptidoglycan structure
– N-acetylglucosamine
– N-acetylmuramic acid
the two alternating sugars that form a backbone for the peptidoglycan sturcutre
which bacteria have the peptide interbridge?
gram +
• composed primarily of peptidoglycan • also contain large amounts of teichoic acids
Gram + cell walls
____- anchor the peptidoglycan layer to the plasma membrane
teichoic acid
• polymers of glycerol or ribitol joined by phosphate groups
teichoic acids
• consist of a thin layer of peptidoglycan
surrounded by an outer membrane
• outer membrane composed of lipids, lipoproteins, and lipopolysaccharide (LPS)
• no teichoic acids
Gram - cell walls
•______ lipoproteins connect outer membrane to peptidoglycan
Braun’s
Seen in gram -????
– sites of direct contact (possibly true membrane
fusions) between plasma membrane and outer
membrane
– substances may move directly into cell through
adhesion sites
Adhesion sites
Lipopolysaccharides (LPSs)
are seen on gram ___ surfaces
gram -
– lipid A
– core polysaccharide
– O side chain (O antigen)
the three parts of LPS Lipopolysaccarides
What is the exterior part of the LPS?
the O side Chain
