Regulation Of Animal Cell Shape (L6)

Question 1

What is the cytoskeleton?

Answer 1

• helps maintain cell shape + position of organelles within cell
• provides stability to the cell while still being dynamic
• allows rapid changes in cell shape

Question 2

What are the 3 main components of the cytoskeleton?

Answer 2

Microtubules/microfilament/intermediate filaments

Question 3

What are the main functions of the microtubule?

Answer 3

• maintain cell shape (by resisting compression
• provide cell motility
• involved in organelle motility (via ATP) (allows vesicles to transport proteins across the cell)

Question 4

This resists tension and forms a cortical network under the plasma membrane which makes it less fluid and maintains cell shape in doing so.

Answer 4

Microfilalments

Question 5

These are made of various proteins. Usually supercoiled into cables which form relatively permanent cellular structures.

Answer 5

Intermediate filaments

Question 6

What are the 3 major types of cell junctions?

Answer 6

Tight junctions, gap junctions, desmosomes

Question 7

What is the difference between tight junction/gap junction/desmosome?

Answer 7

Tight junctions - cells are tightly pressed together; prevents movement of fluid across cell layers

Desmosomes - anchoring junctions; provides attachments between sheets of cells; connected into the cell via intermediate filaments

Gap junctions - a point of contact between two cells where ions and small molecules can be passed; allows rapid cell to cell communication

Question 8

Where do cells lie?

Answer 8

extracellular matrix

Question 9

What is the most abundant glycoprotein in the ECM?

Answer 9

collagen

Question 10

These are proteins with carbohydrates

Answer 10

Glycoproteins

Question 11

What are collagen fibres embedded on? What are their functions?

Answer 11

Proteoglycan complex matrix (like a branched matrix). They trap water in the ECM, which resists compression and helps retain tissue shape.

Question 12

A form of glycoprotein (kinda like a dinosaur which attaches cells to the ECM

Answer 12

Fibroconectins

Question 13

These connect ECM to cytoskeleton

Answer 13

Integrin/membrane proteins

Question 14

What are non-animal functions of microfilaments?

Answer 14

Amoeboid movement and cytoplasmic streaming in plants

Question 15

An ________ is less dynamic than microtubules or microfilaments.

Answer 15

Intermediate filament

Question 16

T/F: Intermediate filaments may remain after the cell that made them has died.

Answer 16

True

Question 17

Microfilaments resist ______

Answer 17

Tension

Question 18

What are the 3 types of cell junctions?

Answer 18

Gap junction, desmosome, tight junctions

Question 19

Desmosomes are connected into the cell through?

a) microfilaments
b) intermediate filaments
c) gap junctions

Answer 19

Intermediate filaments

Question 20

This is a point of cytoplasmic contact between two cells and allows rapid cell to cell communication.

Answer 20

Gap junctions

Question 21

The extracellular matrix composition varies between tissues. T/F:

Answer 21

True

Question 22

These are proteins with extensive sugar additions, they trap water in the ECM. This is what the collagen in the ECM is embedded on.

Answer 22

Proteoglycan

Question 23

_______ resists compression and thus helps retain cell shape. ________ resists tension

Answer 23

Water; collagen