MICRO 401 EXAM 2 QUESTIONS AND VERIFIED
ANSWERS
Typical eucarya cell - Answers - -nucleated
-usually multiple chromosomes
-ER host ribosomes
-mitochondria
Typical prokaryote - Answers - -small and less complex that eukaryotic cells
-no nucleus
-no mitochondria
-no membrane bound organelles
-DNA usually in one circular chromosome
-2-8 microns long
Bacteria cell wall - Answers - contains peptidoglycan
Archea cell wall - Answers - cell membrane covered by S-layer (wall) of glycoproteins or
polysacchrides
Fungi cell wall - Answers - often contains chitin
Plant cell wall - Answers - usually contains cellulose
What common bacteria shares name with rod shape? - Answers - bacillus is a genus
name of bacteria which are common in marine sendiments
-bacillus is the name for rod shaped bacteria
Outside cell wall - Answers - outside cell wall: slime layer capsule, or extracellular
polysaccharide (EPS)
slime layer-loose, unstructured fluid
capsule- attached to cell many hinder phagocytosis
EPS- allows attachment to surfaces. provides physically barrier to antibiotics and bleach
taxis - Answers - Movement toward or away from a stimulus.
Cell wall - Answers - surrounds cytoplasmic membrane in all known marine prokaryotes,
but not all prokaryotes
-rigid, determines cell shape and anchors flagella
Bacterial cell wall - Answers - Exploit in two ways:
1. classification:
Gram+ or gram- based on wall composition
2. control:
, enzyme in tears, saliva, egg white, breaks down bacteria cell walls
Gram-negative bacteria - Answers - 1. thinner than gram+ cell wall: ~20% peptidoglycan
(aka murein) ie alternating molecules of N-acetylglucosamine and N-acetylmuramic acid
2. outer membrane contains lipopolysacchride (LPS) also known as endo toxin. unique
to this bacteria
Gram-positive bacteria - Answers - ~90% peptidoglycan and teichoic acid, which links to
muramic acid to join peptidoglycans
-rare among pelagic marine bacteria, more common in sediments
Bacteria and archea cytoplasmic membrane - Answers - Plasma membrane
-fluid mosaic model: phospholipids arrange hydrophilic heads out
-allow passage of small molecules
-membrane bound transporters allow passage of ions and other large molecules
Archea membrane - Answers - isoprenoids linked to L-glycerol by ether linkages
-biomarkers for archea
Bacteria cell membrane - Answers - fatty acids linked to D-glycerol by ester linkages
-contain hopanoids(five rings)
Eucarya cell membrane - Answers - fatty acids linked to D-glycerol by ester linkages
-contain sterols (4 rings)
What varies between bacterial/euk cell membranes and archea? - Answers - -
Bacteria/eucarya: have ester linkages and D-glycerol
-archea: have ether linkages and contain L-glycerol
Endospores - Answers - -some cells sporulate in poor conditions
Prokaryote genomes - Answers - circular chromosome of 0.11 to ~ 13 mln nt,
-usually contain 1 but may have 2/3
Oligotroph - Answers - heterotrophs growing on media with low organic substrate
Starvation-survival - Answers - microbes in the ocean survive long periods in
oligotrophic conditions and thrive when nutrients are right
-rapid growth when right energy sources are available no growth otherwise
-other responses to starvation
-- levels of DNA, RNA some protein decline
-- specific proteins expressed
-- spore formation, rare in pelagic bacteria, common in sedimentary
Nutrient 'quality' - Answers - adding a nutrient may not elicit a response quality and
quantity are important
ANSWERS
Typical eucarya cell - Answers - -nucleated
-usually multiple chromosomes
-ER host ribosomes
-mitochondria
Typical prokaryote - Answers - -small and less complex that eukaryotic cells
-no nucleus
-no mitochondria
-no membrane bound organelles
-DNA usually in one circular chromosome
-2-8 microns long
Bacteria cell wall - Answers - contains peptidoglycan
Archea cell wall - Answers - cell membrane covered by S-layer (wall) of glycoproteins or
polysacchrides
Fungi cell wall - Answers - often contains chitin
Plant cell wall - Answers - usually contains cellulose
What common bacteria shares name with rod shape? - Answers - bacillus is a genus
name of bacteria which are common in marine sendiments
-bacillus is the name for rod shaped bacteria
Outside cell wall - Answers - outside cell wall: slime layer capsule, or extracellular
polysaccharide (EPS)
slime layer-loose, unstructured fluid
capsule- attached to cell many hinder phagocytosis
EPS- allows attachment to surfaces. provides physically barrier to antibiotics and bleach
taxis - Answers - Movement toward or away from a stimulus.
Cell wall - Answers - surrounds cytoplasmic membrane in all known marine prokaryotes,
but not all prokaryotes
-rigid, determines cell shape and anchors flagella
Bacterial cell wall - Answers - Exploit in two ways:
1. classification:
Gram+ or gram- based on wall composition
2. control:
, enzyme in tears, saliva, egg white, breaks down bacteria cell walls
Gram-negative bacteria - Answers - 1. thinner than gram+ cell wall: ~20% peptidoglycan
(aka murein) ie alternating molecules of N-acetylglucosamine and N-acetylmuramic acid
2. outer membrane contains lipopolysacchride (LPS) also known as endo toxin. unique
to this bacteria
Gram-positive bacteria - Answers - ~90% peptidoglycan and teichoic acid, which links to
muramic acid to join peptidoglycans
-rare among pelagic marine bacteria, more common in sediments
Bacteria and archea cytoplasmic membrane - Answers - Plasma membrane
-fluid mosaic model: phospholipids arrange hydrophilic heads out
-allow passage of small molecules
-membrane bound transporters allow passage of ions and other large molecules
Archea membrane - Answers - isoprenoids linked to L-glycerol by ether linkages
-biomarkers for archea
Bacteria cell membrane - Answers - fatty acids linked to D-glycerol by ester linkages
-contain hopanoids(five rings)
Eucarya cell membrane - Answers - fatty acids linked to D-glycerol by ester linkages
-contain sterols (4 rings)
What varies between bacterial/euk cell membranes and archea? - Answers - -
Bacteria/eucarya: have ester linkages and D-glycerol
-archea: have ether linkages and contain L-glycerol
Endospores - Answers - -some cells sporulate in poor conditions
Prokaryote genomes - Answers - circular chromosome of 0.11 to ~ 13 mln nt,
-usually contain 1 but may have 2/3
Oligotroph - Answers - heterotrophs growing on media with low organic substrate
Starvation-survival - Answers - microbes in the ocean survive long periods in
oligotrophic conditions and thrive when nutrients are right
-rapid growth when right energy sources are available no growth otherwise
-other responses to starvation
-- levels of DNA, RNA some protein decline
-- specific proteins expressed
-- spore formation, rare in pelagic bacteria, common in sedimentary
Nutrient 'quality' - Answers - adding a nutrient may not elicit a response quality and
quantity are important
