PCB 3023 FINAL EXAM
QUESTIONS AND ANSWERS 2026
– 2027
Your friend has just joined a lab that studies vesicle budding from the
Golgi and has been given a cell line that does not form mature
vesicles. He wants to start designing some experiments but wasn't
listening carefully when he was told about the molecular defect of this
cell line. He's too embarrassed to ask and comes to you for help. He
does recall that this cell line forms coated pits but vesicle budding and
the removal of coat proteins don't happen. Which of the following
proteins might be lacking in this cell line?
(a) clathrin
(b) Rab
(c) dynamin
(d) adaptin - ANSWERS-(c) dynamin
An individual transport vesicle ________.
(a) contains only one type of protein in its lumen.
(b) will fuse with only one type of membrane.
(c) is endocytic if it is traveling toward the plasma membrane.
(d) is enclosed by a membrane with the same lipid and protein
composition as the membrane of the donor organelle. - ANSWERS-
(c) is endocytic if it is traveling toward the plasma membrane.
,Which of the following statements about vesicular membrane fusion
is false?
(a) Membrane fusion does not always immediately follow vesicle
docking.
(b) The hydrophilic surfaces of membranes have water molecules
associated with them that must be displaced before vesicle fusion can
occur.
(c) The GTP hydrolysis of the Rab proteins provides the energy for
membrane fusion.
(d) The interactions of the v-SNAREs and the t-SNAREs pull the
vesicle membrane and the target organelle membrane together so that
their lipids can intermix. - ANSWERS-(c) The GTP hydrolysis of the
Rab proteins provides the energy for membrane fusion.
N-linked oligosaccharides on secreted glycoproteins are attached to
¬¬¬¬¬¬________.
(a) nitrogen atoms in the polypeptide backbone.
(b) the serine or threonine in the sequence Asn-X-Ser/Thr.
(c) the N-terminus of the protein.
(d) the asparagine in the sequence Asn-X-Ser/Thr. - ANSWERS-(d)
the asparagine in the sequence Asn-X-Ser/Thr.
Which of the following statements about disulfide bond formation is
false?
(a) Disulfide bonds do not form under reducing environments.
(b) Disulfide bonding occurs by the oxidation of pairs of cysteine side
chains on the protein.
,(c) Disulfide bonding stabilizes the structure of proteins.
(d) Disulfide bonds form spontaneously within the ER because the
lumen of the ER is oxidizing. - ANSWERS-(d) Disulfide bonds form
spontaneously within the ER because the lumen of the ER is
oxidizing.
Living systems are incredibly diverse in size, shape, environment, and
behavior. It is estimated that there are between 10 million and 100
million different species. Despite this wide variety of organisms, it
remains difficult to define what it means to say something is alive.
Which of the following can be described as the smallest living unit?
(a) DNA
(b) cell
(c) organelle
(d) protein - ANSWERS-cell
The flow of genetic information is controlled by a series of
biochemical reactions that result in the production of proteins, each
with its own specific order of amino acids. Choose the correct series
of biochemical reactions from the options presented here.
(a) replication, transcription, translation
(b) replication, translation, transcription
(c) translation, transcription, replication
(d) translation, replication, transcription - ANSWERS-(a) replication,
transcription, translation
, Proteins are important architectural and catalytic components within
the cell, helping to determine its chemistry, its shape, and its ability to
respond to changes in the environment. Remarkably, all of the
different proteins in a cell are made from the same 20 __________.
By linking them in different sequences, the cell can make protein
molecules with different conformations and surface chemistries, and
therefore different functions.
(a) nucleotides.
(b) sugars.
(c) amino acids.
(d) fatty acids. - ANSWERS-(c)amino acids.
Which statement is NOT true about mutations?
(a) A mutation is a change in the DNA that can generate offspring less
fit for survival than their parents.
(b) A mutation can be a result of imperfect DNA duplication.
(c) A mutation is a result of sexual reproduction.
(d) A mutation is a change in the DNA that can generate offspring that
are as fit for survival as their parents are. - ANSWERS-(c) A mutation
is a result of sexual reproduction.
Changes in DNA sequence from one generation to the next may result
in offspring that are altered in fitness compared with their parents.
The process of change and selection over the course of many
generations is the basis of __________.
(a) mutation.
(b) evolution.
QUESTIONS AND ANSWERS 2026
– 2027
Your friend has just joined a lab that studies vesicle budding from the
Golgi and has been given a cell line that does not form mature
vesicles. He wants to start designing some experiments but wasn't
listening carefully when he was told about the molecular defect of this
cell line. He's too embarrassed to ask and comes to you for help. He
does recall that this cell line forms coated pits but vesicle budding and
the removal of coat proteins don't happen. Which of the following
proteins might be lacking in this cell line?
(a) clathrin
(b) Rab
(c) dynamin
(d) adaptin - ANSWERS-(c) dynamin
An individual transport vesicle ________.
(a) contains only one type of protein in its lumen.
(b) will fuse with only one type of membrane.
(c) is endocytic if it is traveling toward the plasma membrane.
(d) is enclosed by a membrane with the same lipid and protein
composition as the membrane of the donor organelle. - ANSWERS-
(c) is endocytic if it is traveling toward the plasma membrane.
,Which of the following statements about vesicular membrane fusion
is false?
(a) Membrane fusion does not always immediately follow vesicle
docking.
(b) The hydrophilic surfaces of membranes have water molecules
associated with them that must be displaced before vesicle fusion can
occur.
(c) The GTP hydrolysis of the Rab proteins provides the energy for
membrane fusion.
(d) The interactions of the v-SNAREs and the t-SNAREs pull the
vesicle membrane and the target organelle membrane together so that
their lipids can intermix. - ANSWERS-(c) The GTP hydrolysis of the
Rab proteins provides the energy for membrane fusion.
N-linked oligosaccharides on secreted glycoproteins are attached to
¬¬¬¬¬¬________.
(a) nitrogen atoms in the polypeptide backbone.
(b) the serine or threonine in the sequence Asn-X-Ser/Thr.
(c) the N-terminus of the protein.
(d) the asparagine in the sequence Asn-X-Ser/Thr. - ANSWERS-(d)
the asparagine in the sequence Asn-X-Ser/Thr.
Which of the following statements about disulfide bond formation is
false?
(a) Disulfide bonds do not form under reducing environments.
(b) Disulfide bonding occurs by the oxidation of pairs of cysteine side
chains on the protein.
,(c) Disulfide bonding stabilizes the structure of proteins.
(d) Disulfide bonds form spontaneously within the ER because the
lumen of the ER is oxidizing. - ANSWERS-(d) Disulfide bonds form
spontaneously within the ER because the lumen of the ER is
oxidizing.
Living systems are incredibly diverse in size, shape, environment, and
behavior. It is estimated that there are between 10 million and 100
million different species. Despite this wide variety of organisms, it
remains difficult to define what it means to say something is alive.
Which of the following can be described as the smallest living unit?
(a) DNA
(b) cell
(c) organelle
(d) protein - ANSWERS-cell
The flow of genetic information is controlled by a series of
biochemical reactions that result in the production of proteins, each
with its own specific order of amino acids. Choose the correct series
of biochemical reactions from the options presented here.
(a) replication, transcription, translation
(b) replication, translation, transcription
(c) translation, transcription, replication
(d) translation, replication, transcription - ANSWERS-(a) replication,
transcription, translation
, Proteins are important architectural and catalytic components within
the cell, helping to determine its chemistry, its shape, and its ability to
respond to changes in the environment. Remarkably, all of the
different proteins in a cell are made from the same 20 __________.
By linking them in different sequences, the cell can make protein
molecules with different conformations and surface chemistries, and
therefore different functions.
(a) nucleotides.
(b) sugars.
(c) amino acids.
(d) fatty acids. - ANSWERS-(c)amino acids.
Which statement is NOT true about mutations?
(a) A mutation is a change in the DNA that can generate offspring less
fit for survival than their parents.
(b) A mutation can be a result of imperfect DNA duplication.
(c) A mutation is a result of sexual reproduction.
(d) A mutation is a change in the DNA that can generate offspring that
are as fit for survival as their parents are. - ANSWERS-(c) A mutation
is a result of sexual reproduction.
Changes in DNA sequence from one generation to the next may result
in offspring that are altered in fitness compared with their parents.
The process of change and selection over the course of many
generations is the basis of __________.
(a) mutation.
(b) evolution.
