Tortora | 9780137941612| Chapter 1-28 | All Chapters with
Answers and Rationals
Prokaryotic and eukaryotic cells are similar in ther chemical ________ and chemical _________ -
ANSWER: chemical composition and chemical reactions
Prokaryotic cells typically lack _________-_________ ________ (including the nucleus) - ANSWER:
membrane-enclosed organelles
A type of polymer in bacterial cell walls consisting of modified sugars cross-linked by short
polypeptides. - ANSWER: peptidoglycan
peptidoglycan is found in the prokaryotic cells walls but not in the - ANSWER: eukaryotic cell walls
eukaryotic cells have a __________-____ nucleus and other organelles - ANSWER: membrane-bound
_________ _______ are differentiated by morphology, chemical composition, nutritional
requirements, biochemical activities, and souce of energy. - ANSWER: bacterial species
the three basic bacterial shapes are - ANSWER: coccus (spherical)
bacillus (rod shaped)
spiral (twisted)
__________ bacteria can assume several shapes - ANSWER: pleomorphic
(capsule, slime layer or extracellular polysaccharide) is a gelatinous polysaccharide and/or
polypeptide covering - ANSWER: glycocalyx
capsules may protect pathogens from - ANSWER: phagocytosis
inhibits growth as a result of removal of water - ANSWER: Desiccation (drying)
________ enable adherence to surfaces, prevent desiccation, and may provide nutrients. - ANSWER:
capsules
are relatively long filamentous appendages consisting of a filament, hook, and basal body - ANSWER:
flagella
prokaryotic flagella _________ to push (move) the cell - ANSWER: rotate
Motile bacteria exhibit ______; a positive _____ is movement towards an attractant, and a negative
______ is movement away from a repellant - ANSWER: taxis
a molecule that reacts specifically with an antibody or immune lymphocyte - ANSWER: An antigen is
Flagellar (H) protein is a(n) _______ - ANSWER: antigen
spiral cells that move by means of an axial filament (endoflagellum) are called - ANSWER: spirochetes
axial filaments are similar to flagella, except that they ________ _______ _ ___ - ANSWER: wrap
around the cell
_____ help cells adhere to surfaces - ANSWER: fimbriae
, _____ are involved in twitching motility and DNA transfer - ANSWER: pili
the cell wall surrounds the plasma membrane and protects the cell from changes in - ANSWER: water
pressure
the bacterial cell wall consists of peptidoglycan, a polymer consisting of NAG and NAM and short
_________ __ _______ _______ - ANSWER: chains of amino acids
N-acetylglucosamine - ANSWER: NAG
Two sugar derivatives that compose the polysaccharide of peptidoglycan. NAG and NAM - ANSWER:
N-acetylglucosamine and N-acetylmuramic acid
________ interferes with peptidoglycan synthesis - ANSWER: penicillin
_______-________ cell walls consist of many layers of peptidoglycan and also contain teichoic acids -
ANSWER: gram-positive
_______-______ bacteria have a lipopolysaccharide-lipoprotein-phospholipid outer membrane
surrounding a thin peptidoglycan layer. - ANSWER: gram-negative
the outer membrane protects the cell from phagocytosis and from: - ANSWER: penicillin, lysozyme,
and other chemicals
_____ are proteins that permit small molecules to pass through the outer membrane; specific channel
proteins allow other molecules to move thorugh the outer membrane. also known as the protein that
causes disease - ANSWER: porins
the lipopolysaccharide component of the outer membrane consists of sugars (O polysaccharides),
which function as antigens, and lipid A, which is a(n) _______ - ANSWER: endotoxin
the _______ ________-______ complex combines with peptidoglycan - ANSWER: crystal violet-iodine
the ____________ removes the lipid outer membrane of gram-negative bacteria and washes out the
crystal violet - ANSWER: decolorizer
is a bacterial genus that naturally lacks cell walls - ANSWER: mycoplasma
archaea have ____________; they lack peptidoglycan - ANSWER: pseudomurein
______-_____ cell walls have a layer of mycolic acid outside a thin peptidoglycan layer - ANSWER:
acid-fast
In the presence of lysozyme, gram-positive cell walls are destroyed, and the remaining cellular
contents are referred to as a - ANSWER: protoplast
In the presence of lysozyme, gram-negative cell walls are not completely destroyed, and the
remaining cellular contents are referred to as a - ANSWER: spheroplast
__ ______ are gram-positive or gram-negative bacteria that do not make a cell wall. - ANSWER: L
forms
Antibiotics such as penicillin interfere with cell wall _______ - ANSWER: synthesis
the plasma membrane encloses the cytoplasm and is a lipid bilayer with _________ and _______
proteins - ANSWER: peripheral and integral