Summary
Alternating growth and rapid shrinkage called dynamic instability lets tubulin polymers explore space and build the spindle.
In depth
Tubulin dimers carrying GTP add to the plus end; after GTP hydrolysis the lattice becomes unstable and can undergo catastrophe, rapid shrinking. Rescue switches back to growth. This dynamic instability lets microtubules search the cytoplasm and capture chromosomes.
Drugs exploit this: paclitaxel stabilises microtubules and colchicine prevents assembly, both blocking mitosis.
The plus end grows with a GTP cap, and the minus end is anchored at the microtubule organising centre (the centrosome in animal cells). Proteins such as EB1 track growing plus ends, and others (MAPs like tau) stabilise or bundle tubules. The rate of growth is about 10 micrometres per minute, which means the spindle can form within minutes.
In neurons, tau stabilises microtubules in axons, and its tangling is a feature of Alzheimer disease. Drugs like vinblastine, colchicine, paclitaxel and nocodazole all disrupt dynamics, which is why they stop mitosis and are used in cancer therapy or research.
Key idea: the instability itself is functional, not a defect; stable microtubules would be unable to explore or capture targets.
Frequently asked questions
What is Microtubule Dynamics?
Alternating growth and rapid shrinkage called dynamic instability lets tubulin polymers explore space and build the spindle.
Which area of biology covers Microtubule Dynamics, and how advanced is it?
Microtubule Dynamics is one of the 52 topics in Cell Biology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Cytokinesis, Cytoskeleton, Mitosis.
Can you give an example of Microtubule Dynamics?
During mitosis microtubules are far more dynamic than during interphase.
What should I learn before Microtubule Dynamics?
Work through the Beginner topics in Cell Biology first, such as Cell Theory, Prokaryotic Cell, Eukaryotic Cell, then return to Microtubule Dynamics. Advanced topics assume the Intermediate vocabulary.
What topics are related to Microtubule Dynamics?
The closest topics to Microtubule Dynamics are Cytokinesis, Cytoskeleton, Mitosis, Cell Cycle. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Microtubule Dynamics?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Microtubule Dynamics. To practise the whole of Cell Biology, use the Cell Biology quiz.
How is Microtubule Dynamics different from Cytokinesis?
Microtubule Dynamics: Alternating growth and rapid shrinkage called dynamic instability lets tubulin polymers explore space and build the spindle. Cytokinesis: Division of the cytoplasm after nuclear division, by a cleavage furrow in animals or a cell plate in plants. Read both side by side and note what each one explains.
How should I study Microtubule Dynamics step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Cytokinesis and explain the difference aloud. Finally, take the Cell Biology quiz and come back to this page for any question you miss.