CYTOSKELETON AND MICROTUBULES

Question 1

What are cytoskeleton ?

Answer 1

Extremely minute , tubular , fibrous , proteinaceous filament.
Found only in eukaryotes

Question 2

What is the function of cytoskeleton ?

Answer 2

FUNCTION -

1. Provides definite shape to the cell
2. Motility
3. Framework to cell

Question 3

What are the different component of cytoskeleton ?

Answer 3

1. Microtubule
2. Microfilament
3. Intermediate filament

Question 4

What are microtubules ?

Answer 4

1. They are the hollow , unbranched , cylindrical structure

2. Diameter - 25nm with central hollow core of 15 nm or 250angstrom

Question 5

Where are the microtubules found ?

Answer 5

they are found in the cytoplasmic matrix.

Question 6

What does the boundary of microtubules composed of ?

Answer 6

It’s boundary is composed of 13 protofilament and each protofilament is made up of alternate unit of alpha and beta tubulin protein.

Question 7

What are the tubulin protein ?

Answer 7

They are the non contractile and globular protein .

Their association and dissociation requires Ca2+ and GTP.

Question 8

Where do these microtubules occurs?

Answer 8

It occurs in centriole , cilia , flagella , basal body , meiotic apparatus.

Question 9

What are the function of these microtubules ?

Answer 9

Function -

1. Generating the shape of cell
2. Form cytoskeleton of cilia and flagella
3. Formation of the spindle fiber and astral ray during the cell division
4. Helps in intracellular transport of the nutrients
5. Position of future cell plate is decided by the microtubules during the cytokinesis in plant cell
6. Helps in the anaphasic movement of chromosomes