BIOL 438 Exam 1 questions with
complete solutions already passed
Describe the cell envelopes of Archaeal cell surfaces. - correct answer ✔✔*varied
S layers attached to plasma membrane
*Pseudomurein (peptidoglycan-like polymer)
*complex polysaccharides, proteins, or glycoproteins found in some other species
*only Ignicoccus has outer membrane
How do Archaeal cell walls differ from bacterial cell walls? - correct answer
✔✔*Lack peptidoglycan
*Most common cell wall is S layer
*May have protein sheath external to S layer
*S layer may be outside membrane and separated by pseudomurein
*Pseudomurein may be outermost layer - similar to Gram-positive microorganisms
What mechanisms do Archaeal cells use for nutrient uptake? - correct answer
✔✔facilitated diffusion and active transport
Described ribosomes within Archaeal specimen. - correct answer ✔✔Complex
structures, sites of protein synthesis
-consisting of protein/RNA
Entire ribosome
-bacterial/archaeal ribosome = 70S
,-eukaryotic (80S) S = Svedburg unit
Bacterial and archaeal ribosomal RNA
-16S small subunit
-23S and 5S in large subunit
-at least one archaeon has additional 5.8S rRNA (also seen in eukaryotic large
subunit)
Proteins in ribosomes vary
-archaea more similar to eukarya than to bacteria, but there are some that are
unique to archaea
Describe the nucleoid within archaeal specimen. - correct answer ✔✔Irregularly
shaped region in bacteria and archaea
Usually not membrane bound (few exceptions)
Location of single circular chromosome and associated proteins
Some evidence for polyploidy in some archaeons
Supercoiling and nucleoid-associated proteins (NAPs, including histones in some
cases) aid in folding and chromosome condensation
Describe pili in regards to archaeal external structures. - correct answer ✔✔not
well understood as of yet
some composed of pilin protein and homologous to bacterial type IV pili proteins
pili formed have a central lumen similar to bacterial flagella, but not bacterial pili
, may be involved in archaeal adhesion mechanisms
What are unique features of archaeal flagella? - correct answer ✔✔Flagella
thinner
More than one type of
flagellin protein
Flagellum are not
hollow
Hook and basal body
difficult to distinguish
Growth occurs at the
base, not the end
Rotation powered by ATP hydrolysis rather than by H+ influx
What is the difference between bacteria and archaea in regards to plasma
membrane lipids? - correct answer ✔✔Bacteria: ester-linked phospholipids and
hopanoids form a lipid bilayer; some have sterols
Archaea: glycerol diethers form lipid bilayers; glycerol tetraethers form lipid
monolayers.
What is the difference between bacteria and archaea in regards to cell wall
constituents? - correct answer ✔✔Bacteria: Peptidoglycan is present in nearly all;
some lack cell walls
Archaea: very diverse but peptidoglycan is always absent; some consist of s-layer
only, others combine s-layer with polysaccharides or proteins or both; some lack
cell walls.
complete solutions already passed
Describe the cell envelopes of Archaeal cell surfaces. - correct answer ✔✔*varied
S layers attached to plasma membrane
*Pseudomurein (peptidoglycan-like polymer)
*complex polysaccharides, proteins, or glycoproteins found in some other species
*only Ignicoccus has outer membrane
How do Archaeal cell walls differ from bacterial cell walls? - correct answer
✔✔*Lack peptidoglycan
*Most common cell wall is S layer
*May have protein sheath external to S layer
*S layer may be outside membrane and separated by pseudomurein
*Pseudomurein may be outermost layer - similar to Gram-positive microorganisms
What mechanisms do Archaeal cells use for nutrient uptake? - correct answer
✔✔facilitated diffusion and active transport
Described ribosomes within Archaeal specimen. - correct answer ✔✔Complex
structures, sites of protein synthesis
-consisting of protein/RNA
Entire ribosome
-bacterial/archaeal ribosome = 70S
,-eukaryotic (80S) S = Svedburg unit
Bacterial and archaeal ribosomal RNA
-16S small subunit
-23S and 5S in large subunit
-at least one archaeon has additional 5.8S rRNA (also seen in eukaryotic large
subunit)
Proteins in ribosomes vary
-archaea more similar to eukarya than to bacteria, but there are some that are
unique to archaea
Describe the nucleoid within archaeal specimen. - correct answer ✔✔Irregularly
shaped region in bacteria and archaea
Usually not membrane bound (few exceptions)
Location of single circular chromosome and associated proteins
Some evidence for polyploidy in some archaeons
Supercoiling and nucleoid-associated proteins (NAPs, including histones in some
cases) aid in folding and chromosome condensation
Describe pili in regards to archaeal external structures. - correct answer ✔✔not
well understood as of yet
some composed of pilin protein and homologous to bacterial type IV pili proteins
pili formed have a central lumen similar to bacterial flagella, but not bacterial pili
, may be involved in archaeal adhesion mechanisms
What are unique features of archaeal flagella? - correct answer ✔✔Flagella
thinner
More than one type of
flagellin protein
Flagellum are not
hollow
Hook and basal body
difficult to distinguish
Growth occurs at the
base, not the end
Rotation powered by ATP hydrolysis rather than by H+ influx
What is the difference between bacteria and archaea in regards to plasma
membrane lipids? - correct answer ✔✔Bacteria: ester-linked phospholipids and
hopanoids form a lipid bilayer; some have sterols
Archaea: glycerol diethers form lipid bilayers; glycerol tetraethers form lipid
monolayers.
What is the difference between bacteria and archaea in regards to cell wall
constituents? - correct answer ✔✔Bacteria: Peptidoglycan is present in nearly all;
some lack cell walls
Archaea: very diverse but peptidoglycan is always absent; some consist of s-layer
only, others combine s-layer with polysaccharides or proteins or both; some lack
cell walls.
