ANSC 221 EXAM QUESTIONS WITH
100% SOLVED ANSWERS
Which of the following is NOT a component of plasma membranes?
A. glycosylated proteins
B. phospholipids
C. glycolipids
D. glycosylated nucleic acids
E. cholesterol - Answer-glycosylated nucleic acids
Which of the following is NOT true of the plasma membrane?
A. It is composed of an extracellular and intracellular layer of phospholipids.
B. The extracellular and intracellular layers or leaflets are highly symmetrical.
C. The membrane contains peripheral proteins.
D. Integral proteins span through the membrane.
E. The membrane contains glycolipids and glycoproteins. - Answer-The extracellular
and intracellular layers or leaflets are highly symmetrical.
N-linked glycosylation is the attachment of a carbohydrate to a nitrogen atom (amide
nitrogen of asparagine (Asn) residue of a polypeptide), while O-linked glycosylation is
the addition of a string of sugars to the oxygen atom of serine or threonine side chains
of polypeptides.
A. True
E. False - Answer-True
The process of covalently attaching a carbohydrate to a protein or lipid is called:
A. protein synthesis
B. acetylation
C. esterification
D. glycosylation
E. facilitated diffusion - Answer-glycosylation
In eukaryotes, cytosol and endomembrane system work together to synthesize most
lipids. This process occurs
,A. in mitochondria.
B. through interactions with glycolipids on extracellular leaflet.
C. in lysosomes.
D. on the trans face of the Golgi apparatus
E. at the cytosolic leaflet of the smooth ER membrane. - Answer-at the cytosolic leaflet
of the smooth ER membrane.
Facilitated diffusion but not passive diffusion requires energy.
A. True
E. False - Answer-False
Exocytosis is the process by which material from inside of the cell is packaged into
vesicles and excreted into the extracellular medium.
A. True
B. False - Answer-True
The following solutes have very low permeability through the plasma membrane.
A. Very small uncharged polar molecules
B. Water and urea
C. Polar organic molecules
D. Charged polar molecules and macromolecules
E. All of above - Answer-Charged polar molecules and macromolecules
Water can freely diffuse through animal cell membranes
A. True
E. False - Answer-False
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a
eukaryotic "amoeba"-like cell is still alive. Which component of the cell membrane might
contribute to maintaining the fluidity of plasma membranes under freezing conditions?
A. peripheral proteins
B. high levels of long fatty acyl tails within the lipid bilayer
C. high levels of unsaturated fatty acyl tails within the lipid bilayer
D. absence of cholesterol
E. high levels of saturated fatty acyl tails within the lipid bilayer - Answer-high levels of
unsaturated fatty acyl tails within the lipid bilayer
A substrate binds an enzyme as a signal molecule binds a
A. second messenger.
B. kinase.
C. receptor.
, D. transcription factor.
E. G-protein. - Answer-receptor
During exposure to elevated glucose, a yeast cell's membrane glucose transporters will
rapidly increase so the cell can import glucose. Which would represent the signal for the
yeast cell?
A. glucose transporters
B. glucose receptors
C. glucose
D. glucose transport into the cell
E. glucose kinase - Answer-glucose
The production of second messengers in signal transduction offers at least two
advantages, speed and
A. specificity.
B. amplification.
C. one-to-one stoichiometry.
D. reversibility.
E. affinity. - Answer-amplification
A hormone binds a receptor and activates the cAMP signal transduction pathway
ultimately leading to the cell response. Which of the following is NOT a likely
mechanism for reversing (or shutting off) cAMP transduction?
A. The hormone dissociating from the receptor.
B. The GTP on the alpha subunit of the G protein is hydrolyzed to GDP
C. Activate phosphodiesterase.
D. Activate adenylyl cyclase.
E. Protein phosphatases remove phosphates from proteins initially activated by protein
kinase A. - Answer-Activate adenylyl cyclase.
Various cells in the body respond to the hormone epinephrine in various ways due to
________.
A. cellular respiration
B. metabolism
C. phosphodiesterase
D. protein kinases
E. differential gene regulation - Answer-differential gene regulation
Unlike enzymes, which convert their substrates into products, receptors do not usually
alter the structure of their ligands.
A. True
100% SOLVED ANSWERS
Which of the following is NOT a component of plasma membranes?
A. glycosylated proteins
B. phospholipids
C. glycolipids
D. glycosylated nucleic acids
E. cholesterol - Answer-glycosylated nucleic acids
Which of the following is NOT true of the plasma membrane?
A. It is composed of an extracellular and intracellular layer of phospholipids.
B. The extracellular and intracellular layers or leaflets are highly symmetrical.
C. The membrane contains peripheral proteins.
D. Integral proteins span through the membrane.
E. The membrane contains glycolipids and glycoproteins. - Answer-The extracellular
and intracellular layers or leaflets are highly symmetrical.
N-linked glycosylation is the attachment of a carbohydrate to a nitrogen atom (amide
nitrogen of asparagine (Asn) residue of a polypeptide), while O-linked glycosylation is
the addition of a string of sugars to the oxygen atom of serine or threonine side chains
of polypeptides.
A. True
E. False - Answer-True
The process of covalently attaching a carbohydrate to a protein or lipid is called:
A. protein synthesis
B. acetylation
C. esterification
D. glycosylation
E. facilitated diffusion - Answer-glycosylation
In eukaryotes, cytosol and endomembrane system work together to synthesize most
lipids. This process occurs
,A. in mitochondria.
B. through interactions with glycolipids on extracellular leaflet.
C. in lysosomes.
D. on the trans face of the Golgi apparatus
E. at the cytosolic leaflet of the smooth ER membrane. - Answer-at the cytosolic leaflet
of the smooth ER membrane.
Facilitated diffusion but not passive diffusion requires energy.
A. True
E. False - Answer-False
Exocytosis is the process by which material from inside of the cell is packaged into
vesicles and excreted into the extracellular medium.
A. True
B. False - Answer-True
The following solutes have very low permeability through the plasma membrane.
A. Very small uncharged polar molecules
B. Water and urea
C. Polar organic molecules
D. Charged polar molecules and macromolecules
E. All of above - Answer-Charged polar molecules and macromolecules
Water can freely diffuse through animal cell membranes
A. True
E. False - Answer-False
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a
eukaryotic "amoeba"-like cell is still alive. Which component of the cell membrane might
contribute to maintaining the fluidity of plasma membranes under freezing conditions?
A. peripheral proteins
B. high levels of long fatty acyl tails within the lipid bilayer
C. high levels of unsaturated fatty acyl tails within the lipid bilayer
D. absence of cholesterol
E. high levels of saturated fatty acyl tails within the lipid bilayer - Answer-high levels of
unsaturated fatty acyl tails within the lipid bilayer
A substrate binds an enzyme as a signal molecule binds a
A. second messenger.
B. kinase.
C. receptor.
, D. transcription factor.
E. G-protein. - Answer-receptor
During exposure to elevated glucose, a yeast cell's membrane glucose transporters will
rapidly increase so the cell can import glucose. Which would represent the signal for the
yeast cell?
A. glucose transporters
B. glucose receptors
C. glucose
D. glucose transport into the cell
E. glucose kinase - Answer-glucose
The production of second messengers in signal transduction offers at least two
advantages, speed and
A. specificity.
B. amplification.
C. one-to-one stoichiometry.
D. reversibility.
E. affinity. - Answer-amplification
A hormone binds a receptor and activates the cAMP signal transduction pathway
ultimately leading to the cell response. Which of the following is NOT a likely
mechanism for reversing (or shutting off) cAMP transduction?
A. The hormone dissociating from the receptor.
B. The GTP on the alpha subunit of the G protein is hydrolyzed to GDP
C. Activate phosphodiesterase.
D. Activate adenylyl cyclase.
E. Protein phosphatases remove phosphates from proteins initially activated by protein
kinase A. - Answer-Activate adenylyl cyclase.
Various cells in the body respond to the hormone epinephrine in various ways due to
________.
A. cellular respiration
B. metabolism
C. phosphodiesterase
D. protein kinases
E. differential gene regulation - Answer-differential gene regulation
Unlike enzymes, which convert their substrates into products, receptors do not usually
alter the structure of their ligands.
A. True
