Lecture 9 - Regulation of Animal Cell shape

Question 1

The cytoskeleton is highly
__________ but still provides
___________

Answer 1

The cytoskeleton is highly
dynamic but still provides
stability

Question 2

What are the three main components that the cytoskeleton is made up of?

Answer 2

Intermediate filaments, Microfilaments and Microtubules

Question 3

Microtubules resist…

Answer 3

Compression

Question 4

What are microtubules composed of?

Answer 4

Tublin subunits

Question 5

Microtubules provide cell…

Answer 5

Structure and motility

Question 6

What is the direction of flagella?

Answer 6

“Swimming”

Question 7

What is the direction of cillia?

Answer 7

Side to side

Question 8

What are microfilaments composed of?

Answer 8

A double chain of actin subunits

Question 9

Microfilaments resist…

Answer 9

Tension

Question 10

Interactions between actin and ______ _______ such as myosin support cell movement

Answer 10

Motor proteins

Question 11

What allows for muscle contraction?

Answer 11

Actin-myosin

Question 12

What are intermediate filaments made of?

Answer 12

Keratins (hair), lamins (nucleus) and neurofilamens (neurons)

Question 13

What do the intermediate filaments help with? (2)

Answer 13

• Maintain cell shape
• Anchor organelles

Question 14

T or F

Microtubules are involved in cell
motility (e.g. cilia movement)

Answer 14

True

Question 15

T or F

Microfilaments resist compression

Answer 15

False, they resist tension. Microtubules resist compression

Question 16

T or F

Keratins are an example of
microtubules

Answer 16

False, Keratins are an example of intermediate filaments

Question 17

What are the three major types of cell junctions?

Answer 17

• Tight Junctions
• Desmosomes
• Gap Junctions

Question 18

What are the roles of tight junctions?

Answer 18

• Hold neighbouring cells tightly
  pressed together
• Prevents movement of fluid
  across cell layers

Question 19

What are the benefits of gap junctions?

Answer 19

• Ions and small molecules can
  pass from cell to cell
• Allows rapid cell to cell
  (intercellular) communication

Question 20

How are cells joined together?

Answer 20

The extracellular matrix

Question 21

What is the ECM composed of?

Answer 21

Material secreted from cells by constitutive exocytosis

Question 22

What are most ECM proteins called?

Answer 22

Glycoproteins (protein with
added carbohydrates)

Question 23

What is the most abundant ECM
glycoprotein?

Answer 23

Collagen

Question 24

Which component of the cytoskeleton resists compression AND is involved in cell motility?

Answer 24

Microtubules

Question 25

Which component of the cytoskeleton is involved with contraction of muscle?

Answer 25

Actin-myosin

Question 26

Which component of the cytoskeleton is involved with holding organelles in place?

Answer 26

Microtubules

Question 27

Which component of the cytoskeleton is involved with a flagellum?

Answer 27

Microtubules

Question 28

What are two types of microtubules?

Answer 28

Cilia and flagella

Question 29

Which of the following best describes a cell junction that strongly
anchors cells together:
A. Tight junction
B. Desmosome
C. Gap junction
D. ECM

Answer 29

Tight junction

Question 30

What are desmosomes?

Answer 30

• Anchoring junction
• Provide attachments between
  sheets of cells e.g. muscle
• Connected into the cell by
  intermediate filaments

Question 31

What is the role of fibronectins (glyoproteins)?

Answer 31

Attaching cells to ECM

Question 32

What is the role of integrins (membrane proteins)?

Answer 32

Connecting the ECM to cytoskeleton.