MCB 150 ACTUAL EXAM EXAM FULL
QUESTIONS AND CORRECT ANSWERS
FINAL PAPER 2026 GUARANTEED TO
PASS.
⫸ What is tubulin Answer: a dimer of alpha-tubulin (GTP) and beta-
tubulin (GDP)
⫸ How do tubulin dimers form MTS? Answer: they polymerize,
assemble mt head to tail so mt has polarity
⫸ Which end do polymerization and depolymerization happen on
MT? Answer: possible at both ends, but usually occurs at plus end bc
minus end is anchored into centrosome
⫸ What happens once there is a dimer addition to a microtubule?
Answer: GTP in b-tubulin is hydrolyzed and turned into GDP, GTP in
a-tubulin is not hydrolyzed for stability
⫸ Dynamic instability and GTP cap Answer: GTP bound tubulin
prevents subunits from peeling away so if polymerization slows down
GTP cap is hydrolyzed and microtubule starts depolymerizing
⫸ Tubulin + GTP Answer: = polymerization
, ⫸ Tubulin + no GTP Answer: = depolymerization
⫸ Does GTP bound tubulin have high or low affinity for tubulin?
Answer: high
⫸ Does GDP bound tubulin have high or low affinity for tubulin?
Answer: low
⫸ Colchicine and Colcemid affect on microtubules Answer: Binds
tubulin->induces depolymerization->non-specifically affects all
microtubules
⫸ Vincristine and vinblastine affect on microtubules Answer: Binds
tubulin->induces depolymerization->targets rapidly dividing cells
⫸ Taxol affect on microtubules Answer: binds microtubules-
>stabilizes microtubules->targets rapidly dividing cells
⫸ Function of microtubules Answer: interphase cell (guiding
intracellular transport), dividing cell (segregating chromosomes
during mitosis), ciliated cell (propulsion or sweeping of fluids over
membranes)
⫸ Where do new microtubules come from? Answer: mts originate
from the microtubule organizing center (MTOC)
QUESTIONS AND CORRECT ANSWERS
FINAL PAPER 2026 GUARANTEED TO
PASS.
⫸ What is tubulin Answer: a dimer of alpha-tubulin (GTP) and beta-
tubulin (GDP)
⫸ How do tubulin dimers form MTS? Answer: they polymerize,
assemble mt head to tail so mt has polarity
⫸ Which end do polymerization and depolymerization happen on
MT? Answer: possible at both ends, but usually occurs at plus end bc
minus end is anchored into centrosome
⫸ What happens once there is a dimer addition to a microtubule?
Answer: GTP in b-tubulin is hydrolyzed and turned into GDP, GTP in
a-tubulin is not hydrolyzed for stability
⫸ Dynamic instability and GTP cap Answer: GTP bound tubulin
prevents subunits from peeling away so if polymerization slows down
GTP cap is hydrolyzed and microtubule starts depolymerizing
⫸ Tubulin + GTP Answer: = polymerization
, ⫸ Tubulin + no GTP Answer: = depolymerization
⫸ Does GTP bound tubulin have high or low affinity for tubulin?
Answer: high
⫸ Does GDP bound tubulin have high or low affinity for tubulin?
Answer: low
⫸ Colchicine and Colcemid affect on microtubules Answer: Binds
tubulin->induces depolymerization->non-specifically affects all
microtubules
⫸ Vincristine and vinblastine affect on microtubules Answer: Binds
tubulin->induces depolymerization->targets rapidly dividing cells
⫸ Taxol affect on microtubules Answer: binds microtubules-
>stabilizes microtubules->targets rapidly dividing cells
⫸ Function of microtubules Answer: interphase cell (guiding
intracellular transport), dividing cell (segregating chromosomes
during mitosis), ciliated cell (propulsion or sweeping of fluids over
membranes)
⫸ Where do new microtubules come from? Answer: mts originate
from the microtubule organizing center (MTOC)
