Cytoskeleton

Question 1

Cytoskeleton components

Answer 1

1) microfilaments
2) intermediate filaments
3) microtubules

Question 2

Microfilaments

Answer 2

Maintain cell shape

Made of actin

Question 3

Intermediate filaments

Answer 3

More permanent structures 
Variable composition (keratin, Lamin)

Question 4

Cytoskeleton

Answer 4

• structural support
• locomotion
• intercellular anchor
• involved in mitosis

Question 5

Microtubules

Answer 5

• Motility (cilia,flagella), cell division

- made of Tubulin

Question 6

The structural role of microfilaments

Answer 6

Bear tension, resisting pulling forced within the cell

Question 7

What is the cortex

Answer 7

A 3D network inside the plasma membrane to help support the cells shape made out of microfilaments

Question 8

Core of Microvilli of intestinal cells is made of

Answer 8

Made up of bundles of microfilaments

Question 9

Microfilaments that function in cellular motility contain ?

Answer 9

The protein myosin in addition to actin

Question 10

Amoeboid movement

Answer 10

Produced by the localized contraction brought about by actin and myosin

Question 11

Pseudopodia (Cellular extensions )

Answer 11

Extend and contract through the reversible assembly and contraction of actin subunits into microfilaments

Question 12

Cytoplasmic streaming

Answer 12

Circular flow of cytoplasm within cells, speed distribution of materials within the cell.

Question 13

Function of intermediate filaments

Answer 13

Support cell shape and fix organelles in place

Question 14

Hollow rods of 25 in diameter and 200nm to 25 microns long

Answer 14

Microtubules

Question 15

Microtubules functions

Answer 15

Shaping cell
Guiding movement of organelles
Separating chromosomes during cell division

Question 16

Types of Tubulin

Answer 16

B-Tubulin

Alpha-Tubulin

Question 17

Centrosome

Answer 17

Microtubules-organizing center.

In animal cells the centrosome has a pair of centrioles each with nine triplets of microtubules arranged in a ring

Question 18

What controls the beating of Cilia and flagella

Answer 18

Microtubules

Question 19

Common structure of cilia and flagella ?

Answer 19

A core of microtubules sheathed by the plasma membrane

• basal body that anchors cilium or flagellum.
• motor protein called dynein which drives the bending movements of a cilium or flagellum.

Question 20

Microfilaments structure

Answer 20

Two intertwined strands of actin, each a polymer of actin subunit

Question 21

Microfilaments diamer and subunit

Answer 21

7 nm diameter and subunit is actin

Question 22

Microfilaments (actin filaments) functions

Answer 22

• maintenance of cell shape.
• changes in cell shape
• muscle contraction
• cytoplasmic streaming
• cell motility ( as in pseudopodia)
• cell division (cleavage furrow formation)

Question 23

Intermediate filaments structure

Answer 23

Fibrous proteins supercoiled into ticker cables

Question 24

Intermediate filaments diameter ? Subunits?

Answer 24

8-12nm

Protein subunit: several different proteins depending on cell type example : keratins

Question 25

Main functions of intermediate Filaments ?

Answer 25

• Maintenance of cell shape (tension bearing elements)
• anchorage of nucleus and certain other organelles
• formation of nuclear lamina

Question 26

Microtubules (Tubulin polymers) structure ?

Answer 26

Hollow tubes; walls consist of 13 columns of Tubulin molecules.

Question 27

Microtubules diameter and protein subunit?

Answer 27

25 nm w/ 15nm lumen

Subunits: Tubulin a dimer consisting of alpha-Tubulin and B-Tubulin

Question 28

Microtubules functions ?

Answer 28

Maintenance cell shape
-cell motility as in cilia or flagella
-chromosome movements in cell division
Organelles movements