1
Molecular Cell Biology ACTUAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS WITH
RATIONALES || 100% GUARANTEED PASS <RECENT
VERSION>
Gamma-Turc - (answers)This protein complex is recruited to microtubule
organizing centers in order to promote nucleation of microtubules, and to act as a
minus end cap which prevents microtubule disassembly after GTP hydrolysis.
Myosin - (answers)This plus-end directed microfilament motor protein promotes
vesicle movement and cell contraction.
Kinesin - (answers)This plus-end directed microtubule motor protein helps to
promote movement and positioning of cytoplasmic organelles and vesicles.
Microtubule - (answers)This polarized filament network forms dynamic, but rigid,
structures that are primarily used for transport and positioning of cytoplasmic
organelles and vesicles.
Microfilament - (answers)This polarized filament network forms a diverse range
of filament structures that can promote cell migration, contraction, adhesion and
cellular structure.
Alpha-actinin - (answers)This protein promotes formation of parallel
microfilament arrays found in contractive fibers of muscle cells as well as
migrating cells.
, 2
Tropomodulin - (answers)This minus end capping protein prevents
growth/shrinkage of actin filaments in contractive fibers of muscle cells and
migrating cells:
G-protein coupled receptor - (answers)Binding of a ligand to these membrane
proteins activates their GEF activity so that the Galpha subunit of trimeric G-
proteins they associate with become activated.
Adenylate Cyclase - (answers)This protein functions both to generate cAMP and
as a GAP to activate GTPase activity of a bound Galpha protein.
Protein Kinase A (PKA) or cAMP dependent protein kinase - (answers)Activation of
this protein by association with a 2nd messenger, such as cAMP, results in
phosphorylation of substrates that alter function of cytosolic proteins to quickly
change cell behavior as well as nuclear proteins to have long-term effects on cell
behavior.
Cyclin A/B - (answers)This protein positively regulates CDK1 so it become active
and promotes entry into M-phase.
Cdc20 - (answers)This protein allows progression from metaphase to anaphase by
allowing the E3 ligase, APC, to associate with securin and target it for poly-
ubiquitination.
Cdh1 - (answers)This protein promotes progression through anaphase by allowing
the E3 ligase, APC, to associate with cyclins A&B so that CDK1 can no longer
Molecular Cell Biology ACTUAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS WITH
RATIONALES || 100% GUARANTEED PASS <RECENT
VERSION>
Gamma-Turc - (answers)This protein complex is recruited to microtubule
organizing centers in order to promote nucleation of microtubules, and to act as a
minus end cap which prevents microtubule disassembly after GTP hydrolysis.
Myosin - (answers)This plus-end directed microfilament motor protein promotes
vesicle movement and cell contraction.
Kinesin - (answers)This plus-end directed microtubule motor protein helps to
promote movement and positioning of cytoplasmic organelles and vesicles.
Microtubule - (answers)This polarized filament network forms dynamic, but rigid,
structures that are primarily used for transport and positioning of cytoplasmic
organelles and vesicles.
Microfilament - (answers)This polarized filament network forms a diverse range
of filament structures that can promote cell migration, contraction, adhesion and
cellular structure.
Alpha-actinin - (answers)This protein promotes formation of parallel
microfilament arrays found in contractive fibers of muscle cells as well as
migrating cells.
, 2
Tropomodulin - (answers)This minus end capping protein prevents
growth/shrinkage of actin filaments in contractive fibers of muscle cells and
migrating cells:
G-protein coupled receptor - (answers)Binding of a ligand to these membrane
proteins activates their GEF activity so that the Galpha subunit of trimeric G-
proteins they associate with become activated.
Adenylate Cyclase - (answers)This protein functions both to generate cAMP and
as a GAP to activate GTPase activity of a bound Galpha protein.
Protein Kinase A (PKA) or cAMP dependent protein kinase - (answers)Activation of
this protein by association with a 2nd messenger, such as cAMP, results in
phosphorylation of substrates that alter function of cytosolic proteins to quickly
change cell behavior as well as nuclear proteins to have long-term effects on cell
behavior.
Cyclin A/B - (answers)This protein positively regulates CDK1 so it become active
and promotes entry into M-phase.
Cdc20 - (answers)This protein allows progression from metaphase to anaphase by
allowing the E3 ligase, APC, to associate with securin and target it for poly-
ubiquitination.
Cdh1 - (answers)This protein promotes progression through anaphase by allowing
the E3 ligase, APC, to associate with cyclins A&B so that CDK1 can no longer
