Module 2/ Microtubules

Question 1

Microtubules

Answer 1

-Thick hollow rod composed of tubulin proteins.

-The microtubule has a plus end on one side and a negative end on the other.

-It can grow and shrink in length from the plus end.

-The minus side is attached to the centrosome.

Question 2

What are the two subunits of microtubules?

Answer 2

Alpha tubulin and beta tubulin

Question 3

Movement of microtubule

Answer 3

-They are involved in the movement of organelles, vesicles and enzymes across the cell.

-The movement are caused by motor proteins powered by ATP.

Question 4

Kinesin

Answer 4

They move cargo towards the plus the end of the microtubules

Question 5

Dynein

Answer 5

They move cargo towards the minus end of microtubules

Question 6

Centrosome

Answer 6

Microtubules are involved in the separation of chromosomes during mitosis. They radiate from the centrosome.

Centrosomes are a structure present in the cytoplasm of animal cells near the nucleus that function as a microtubule-organizing centre (MTOC) and is important during cell division.

Question 7

Centriole

Answer 7

A centrosome has two centrioles that are perpendicular to one another.

Centriole are a cylindrical structure in the centrosome of an animal cell composed of 9 microtubules triplets (9+0 arrangement)

Question 8

Flagella and cilia

Answer 8

Both cilia and flagella are appendages in eukaryotic cells that contain microtubules and are used in locomotion or used to move fluid around and feed (cilia).

Both have a core (axoneme) made of nine outer doublet microtubules and two inner single microtubules (“9+2” arrangement). These microtubules are covered by the plasma membrane.

Question 9

Locomotion of microtubule

Answer 9

The sliding of microtubules onto each other depends on a motor proteins (dynein)