Microtubule Structure and Function

The video provides an in-depth look at microtubules, a key component of the cytoskeleton. It covers their structure, including the role of alpha and beta tubulin, and how they assemble into protofilaments. The video explains the function of microtubule organizing centers, such as centrosomes and basal bodies, in facilitating rapid assembly. It also discusses the dynamic nature of microtubules, regulated by GTPases and microtubule-associated proteins, which control their lengthening and shortening during cellular processes like mitosis and meiosis.

What is one of the primary functions of microtubules in the cell?

• To synthesize proteins

• To form cilia and flagella for cell movement

• To produce energy for the cell

• To store genetic information

What are the two types of tubulin monomers that compose microtubules?

• Gamma and delta tubulin

• Alpha and beta tubulin

• Sigma and theta tubulin

• Epsilon and zeta tubulin

What is the role of gamma tubulin in microtubule assembly?

• It breaks down microtubules

• It binds to DNA during cell division

• It speeds up assembly by bypassing nucleation

• It forms the outer layer of microtubules

Where are centrosomes typically located within a cell?

• Near the cell membrane

• Near the nucleus

• In the mitochondria

• In the Golgi apparatus

What is the primary function of basal bodies?

• To transport molecules across the cell membrane

• To store cellular waste

• To serve as nucleation sites for cilia and flagella

• To synthesize proteins

What regulates the dynamic process of microtubule lengthening and shortening?

• Lipid molecules

• DNA sequences

• Small GTPases

• Large proteins

What happens during the process of microtubule catastrophe?

• Microtubules become more stable

• Microtubules begin to fall apart

• Microtubules form new branches

• Microtubules double in length

Which protein is known to destabilize the plus end of microtubules?

• Dynein

• Actin

• Kinesin 13

• X map 215

What is the role of microtubule-associated proteins (MAPs)?

• To transport DNA

• To synthesize new microtubules

• To regulate the rate of microtubule addition

• To break down microtubules

What is the main reason microtubule assembly is faster at organizing centers?

• They contain more DNA

• They are closer to the cell membrane

• They bypass the nucleation step

• They have more energy