C
LO
BIO 93 MIDTERM 2 REVIEW
YC
QUESTIONS AND CORRECT
DETAILED / VERIFIED
D
ANSWERS LATEST UPDATE
U
ST
,Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is
_____. - ANS transferring of information from DNA to messenger RNA
What is the first of the two main steps of protein synthesis? - ANS Transcription
Which molecules do not normally cross the nuclear membrane? - ANS DNA
True or False: The nuclear envelope is continuous with the golgi apparatus - ANS
False; the nuclear envelope is continuous with the ER
K
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. - ANS False;
C
Cytoplasmic proteins called importins bind to large proteins containing an NLS and
mediate their transport across the nuclear membrane through an active transport
(energy-requiring) process.
LO
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? - ANS
Passive transport; it is small enough to diffuse through nuclear pores
YC
In experiments to test whether a protein can enter the nucleus, why would proteins be
labeled with fluorescent molecules? - ANS To make the protein easy to see
What do fluorescent tags do? - ANS Make the location of the proteins easy to
visualize
D
Nucleoplasmin is a nuclear protein. This protein was divided into two segments and
U
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
ST
these results? - ANS Only one of the two fusion proteins possesses a nuclear
localization signal; the nuclear localization signal is only present in the fusion protein
that enters the nucleus
Which organelle plays a role in intracellular digestion? - ANS Lysosome
What is the function of the smooth ER? - ANS Lipid synthesis, poison detoxification,
calcium ion storage
What is the function of the rough ER? - ANS Protein synthesis
, What is the function of the golgi apparatus? - ANS Protein modification and sorting,
cisternal maturation
What is the function of a lysosome? - ANS Macromolecule digestion/hydrolysis,
autophagy
Where are the enzymes and membranes of a lysosome made? - ANS Rough ER and
golgi apparatus
K
What proteins are synthesized by bound ribosomes? - ANS Lysosomal enzyme, ER
protein, insulin
C
Where are proteins that function in the cytosol or in the nucleus synthesized? - ANS
Free ribosomes
LO
Where are proteins that function within the endomembrane system or those destined for
secretion synthesized? - ANS Bound ribosomes
What is the pathway that a secretory protein follows from synthesis to secretion? - ANS
YC
Protein synthesis - ER - cis Golgi cisterane - medial golgi cisternae - trans golgi
cisternae - plasma membrane - extracellular space
True or false: each of the transport steps for a secretory protein requires specialized
proteins to ensure cargo is sent to the proper location - ANS True
D
Mitochondria are found in ____ - ANS Plant and animal cells
U
What does the prokaryotic cell contain that eukaryotes don't? - ANS Nucleoid
ST
What does the eukaryotic cell contain that prokaryotes don't? - ANS Lysosome,
mitochondria, nucleolus
In eukaryotic flagella, the fibers that slide past one another due to the activity of dynein
proteins are - ANS Microtubules
Many cell organelles, most notably the nucleus, are anchored by ___, which are
assembled from a diverse class of proteins - ANS Intermediate filaments
Centrosomes are sites where protein dimers assemble into - ANS Microtubules