the cytoskeleton

What is the cytoskeleton?

An extensive network of protein fibres within the cytoplasm.

What are the main components of the cytoskeleton?

Microfilaments, microtubules and intermediate filaments.

What are microfilaments made from?

Actin.

What are microtubules made from?

Tubulin.

What are intermediate filaments?

Protein fibres that form part of the cytoskeleton and help provide structural support.

What is one function of the cytoskeleton?

It forms tracks along which organelles and vesicles can move.

How does the cytoskeleton help transport organelles?

Organelles and vesicles move along protein fibres that act as tracks.

How does the cytoskeleton help cell movement?

It enables cell movement using structures such as cilia and flagella.

How does the cytoskeleton help maintain cell structure?

It provides structural support and helps position organelles within the cell.

What is a flagellum?

A long cell-surface projection involved in cell movement.

What is the arrangement of microtubules in a flagellum?

A 9+2 arrangement.

What does the 9+2 arrangement mean?

Nine pairs of microtubules surround a central pair of microtubules.

What are cilia?

Hair-like cell-surface projections made from microtubules that can move substances across the cell surface.

How does the cytoskeleton enable movement using cilia and flagella?

Microtubules interact with motor proteins to produce movement.

How can organelles and vesicles move along microtubules?

Motor proteins attach to the organelle or vesicle and move it along the microtubule.

Which motor proteins are involved in movement along microtubules?

Dynein and kinesin.

What do dynein and kinesin do?

They move organelles and vesicles along microtubules using ATP.

Do dynein and kinesin move in the same direction?

No. They generally move in opposite directions along microtubules.

How do motor proteins obtain energy for movement?

They use ATP.

What happens to microtubules during movement?

The microtubules can change length through addition or removal of tubulin subunits.

How does changing microtubule length contribute to movement?

It helps position and transport organelles and vesicles within the cell.

What can the cytoskeleton hold in position?

Organelles such as mitochondria and structures such as the rough endoplasmic reticulum.

How does the cytoskeleton hold organelles in position?

Protein fibres interact with organelles and help anchor them within the cell.

What is the role of the cytoskeleton in intracellular transport?

It provides tracks for the movement of organelles and vesicles through the cytoplasm.

What is the role of ATP in cytoskeleton-based transport?

ATP provides energy for motor proteins such as dynein and kinesin to move cargo.