Module One, Lecture Five

Question 1

What is the Cytoskeleton?

Answer 1

A network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence

Question 2

What are some functions of the Cytoskeleton? ( 5 )

Answer 2

1. Helps maintain cell shape
2. Helps maintain position of organelles within cells
3. Disassembles and reassembles
4. Allows rapid changes in cell shape
5. Highly dynamic but still provides stability

Question 3

What is the Cytoskeleton made up of? ( 3 )

Answer 3

1. Microtubules
2. Microfilaments
3. Intermediate Filaments

Question 4

What are Microtubules and their fucntion?

Answer 4

Tubular structure; resist compression, thus help maintain cell shape

Question 5

What are Microfilaments and their function?

Answer 5

Smallest component of the cytoskeleton, plays a crucial role in cell movement, structure and division

Question 6

What are Intermediate Filaments made of? ( 3 )

Answer 6

1. Keratin in hair
2. Lamins in the nucleus
3. Neurofilaments in neurons

Question 6

What are Intermediate Filaments and their function?

Answer 6

Structural proteins that provide cells with mechanical strength and stability

Question 7

How are Cells joined together? ( 3 )

Answer 7

Cell Junctions:

1. Tight Junctions
2. Desmosomes
3. Gap Junctions

Question 8

What is the function of Tight Junctions? ( 3 )

Answer 8

1. Holds neighbouring cells tightly pressed together
2. May form a continuous seal
3. Prevents movement of fluid across cell layers

Question 9

What is the function of Desmosomes? ( 3 )

Answer 9

1. Anchoring Junction
2. Provide attachments between sheets of cell e.g muscle
3. Act like rivets

Question 10

What is the function of Gap Junctions? ( 3 )

Answer 10

1. Cytoplasmic contact between two cells
2. Ions and small molecules can pass from cell to cell
3. Allows rapid intercellular communication

Question 11

What is the Extracellular Matrix? ( ECM )

Answer 11

It is composed of material secreted by cells