Bio 1100 EXAM QUESTIONS WITH 100%
COREECT ANSWERS
\.During protein synthesis, the peptide bond between amino acids is formed by the process of
condensation
\.Part A
Which class(es) of amino acids possess side chains that would be unable to form hydrogen
bonds with water?
amino acids with nonpolar side chains
\.Which type of interaction stabilizes the α-helix and the β-pleated sheet structures of
proteins?
hydrogen bonds
\.In solution, why do hydrolysis reactions occur more readily than condensation reactions?
Hydrolysis increases entropy and is exergonic.
\.Van der Waals interactions may result when _____
electrons are not symmetrically distributed in a molecule
\.In a normal cellular protein, where would you expect to find a hydrophobic amino acid like
valine?
in the interior of the folded protein, away from water, or in a transmembrane portion
interacting with lipid fatty acid chains
\.You disrupt all hydrogen bonds in a protein. What level of structure will be preserved?
primary structure
\.Which of the following is the strongest evidence that protein structure and function are
correlated?
Denatured (unfolded) proteins do not function normally.
,\.What type of bond joins the monomers in a protein's primary structure?
peptide bonds
\.What is the function of the nuclear pore complex found in eukaryotes?
It regulates the movement of proteins and RNAs into and out of the nucleus.
\.Which of the following statements about the nuclear envelope is false?
\.The nuclear envelope is composed of two lipid bilayers.
The nuclear envelope is continuous with the Golgi apparatus.
Molecules pass into and out of the nucleus through nuclear pores.
Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore
complex.
The nuclear envelope is continuous with the Golgi apparatus.
\.True or false? Large proteins containing a nuclear localization signal (NLS) bind to the
nuclear pore and enter the nucleus without any expenditure of energy.
False
\.A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in
the nucleus a short time later. What type of transport has taken place?
Passive transport
\.Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked
to the same large cytoplasmic protein, generating two fusion proteins. After injecting these
fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the
cytoplasm. Which of the following conclusions can be drawn from these results?
Only one of the two fusion proteins possesses a nuclear localization signal.
\.How are proteins transported to their correct location in the cell?
Proteins contain molecular "zip codes" that allow them to be shipped to the correct cellular
compartm
\.In receptor-mediated endocytosis, receptor molecules initially project to the outside of the
cell. Where do they end up after endocytosis?
on the inside surface of the vesicle
, \.Eukaryotic cells manufacture cytoskeletal proteins, which help to maintain cell shapes and
functions. What would you predict about these proteins?
They are manufactured on free ribosomes in the cytoplasm.
\.Proteins coded for by nuclear DNA but found within mitochondria move from the cytoplasm
into mitochondria using
signal sequences (peptides)
\.What path does a protein in the secretory pathway take, starting from its site of synthesis?
Rough ER, Golgi apparatus, secretory vesicles, plasma membrane
\.Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with
radioactive leucine and then chased for several hours with nonradioactive leucine.
Photographic emulsions are prepared at different times during the chase. Where would the
black spots appear on an emulsion prepared 3 hours after the pulse?
a. Exterior of the cell
b. Rough ER
c. Golgi apparatus
d. Secretory vesicles
a.
\.Which statement most accurately describes what happens to proteins that lack an ER signal
sequence?
a.They are released into the cytosol
b.They bypass the ER but eventually enter the Golgi apparatus
c.They are inserted in the ER membrane, but do not enter the ER lumen
d.They are inserted into the plasma membrane as transmembrane proteins
a.
\.A white blood cell such as a macrophage engulfing a bacterium is an example of
a.active transport
b.facilitated diffusion
c.pinocytosis
d.phagocytosis
e.exocytosis
d.
COREECT ANSWERS
\.During protein synthesis, the peptide bond between amino acids is formed by the process of
condensation
\.Part A
Which class(es) of amino acids possess side chains that would be unable to form hydrogen
bonds with water?
amino acids with nonpolar side chains
\.Which type of interaction stabilizes the α-helix and the β-pleated sheet structures of
proteins?
hydrogen bonds
\.In solution, why do hydrolysis reactions occur more readily than condensation reactions?
Hydrolysis increases entropy and is exergonic.
\.Van der Waals interactions may result when _____
electrons are not symmetrically distributed in a molecule
\.In a normal cellular protein, where would you expect to find a hydrophobic amino acid like
valine?
in the interior of the folded protein, away from water, or in a transmembrane portion
interacting with lipid fatty acid chains
\.You disrupt all hydrogen bonds in a protein. What level of structure will be preserved?
primary structure
\.Which of the following is the strongest evidence that protein structure and function are
correlated?
Denatured (unfolded) proteins do not function normally.
,\.What type of bond joins the monomers in a protein's primary structure?
peptide bonds
\.What is the function of the nuclear pore complex found in eukaryotes?
It regulates the movement of proteins and RNAs into and out of the nucleus.
\.Which of the following statements about the nuclear envelope is false?
\.The nuclear envelope is composed of two lipid bilayers.
The nuclear envelope is continuous with the Golgi apparatus.
Molecules pass into and out of the nucleus through nuclear pores.
Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore
complex.
The nuclear envelope is continuous with the Golgi apparatus.
\.True or false? Large proteins containing a nuclear localization signal (NLS) bind to the
nuclear pore and enter the nucleus without any expenditure of energy.
False
\.A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in
the nucleus a short time later. What type of transport has taken place?
Passive transport
\.Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked
to the same large cytoplasmic protein, generating two fusion proteins. After injecting these
fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the
cytoplasm. Which of the following conclusions can be drawn from these results?
Only one of the two fusion proteins possesses a nuclear localization signal.
\.How are proteins transported to their correct location in the cell?
Proteins contain molecular "zip codes" that allow them to be shipped to the correct cellular
compartm
\.In receptor-mediated endocytosis, receptor molecules initially project to the outside of the
cell. Where do they end up after endocytosis?
on the inside surface of the vesicle
, \.Eukaryotic cells manufacture cytoskeletal proteins, which help to maintain cell shapes and
functions. What would you predict about these proteins?
They are manufactured on free ribosomes in the cytoplasm.
\.Proteins coded for by nuclear DNA but found within mitochondria move from the cytoplasm
into mitochondria using
signal sequences (peptides)
\.What path does a protein in the secretory pathway take, starting from its site of synthesis?
Rough ER, Golgi apparatus, secretory vesicles, plasma membrane
\.Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with
radioactive leucine and then chased for several hours with nonradioactive leucine.
Photographic emulsions are prepared at different times during the chase. Where would the
black spots appear on an emulsion prepared 3 hours after the pulse?
a. Exterior of the cell
b. Rough ER
c. Golgi apparatus
d. Secretory vesicles
a.
\.Which statement most accurately describes what happens to proteins that lack an ER signal
sequence?
a.They are released into the cytosol
b.They bypass the ER but eventually enter the Golgi apparatus
c.They are inserted in the ER membrane, but do not enter the ER lumen
d.They are inserted into the plasma membrane as transmembrane proteins
a.
\.A white blood cell such as a macrophage engulfing a bacterium is an example of
a.active transport
b.facilitated diffusion
c.pinocytosis
d.phagocytosis
e.exocytosis
d.
