Cytoskeleton

Question 1

Cytoskeleton

Answer 1

a network of fibers extending through the cytoplasm

Question 2

the cytoskeleton provides

Answer 2

mechanical support to the cell and maintain its shape, it is stabilized by a balancing between opposing forces exerted by elements. It provides anchorage for many organelles and cytosolic enzyme molecules

Question 3

cell motility requires

Answer 3

interaction of the cytoskeleton and motor proteins

Question 4

Microtubules

Answer 4

hollow rods constructed from globular proteins called tubulins

Question 5

Each tubulin protein is

Answer 5

a dimer, a tubulin dimer consist of 2 different polypeptides, alpha-tubulin and beta-tubulin

Question 6

Microtubules grow by

Answer 6

adding tubulin dimers, can also be dissassembled

Question 7

Microtubules shape and support

Answer 7

the cell and also serve as tracks along which organelles equipped with motor proteins can move

Question 8

centrosome

Answer 8

microtubules grow out from, are often located near the nucleus

Question 9

Centrosomes function as

Answer 9

compression-resisting guider of the cytoskeleton

Question 10

Centrioles

Answer 10

a pair of nine sets of triplet microtubules arranged in a ring within the centrosome

Question 11

Flagella and Cilia

Answer 11

cellular extension that contain microtubules

Question 12

Unicellular protist are propelled through water by

Answer 12

cilia or flagella that act as locomotor appendages and the sperm of animals, algae, and some plants have flagella

Question 13

The microtubule assembly of a cilium or flagellum is

Answer 13

anchored in the cell by a basal body, which is structurally very similar to a centriole

Question 14

Microfillaments

Answer 14

thin solid rods, also called actin filaments because they are built from molecules of actin, a globular protein

Question 15

microfilaments structure is

Answer 15

a twisted double chain of actin subunits, they form structural networks when certain proteins bind along the side of such a filament and allow a new filament to extend as a branch

Question 16

Microfilaments function in the cytoskeleton

Answer 16

is to bear tension, maintenance of cells shape, muscle contraction, cytoplasmic streaming in plant cells and motility.

Question 17

Thousand of actin filaments and thicker filaments are made of a protein called

Answer 17

myosin, which interact to cause contraction of the muscle cells

Question 18

Actin protein interactions contribute to

Answer 18

cytoplasmic streaming

Question 19

cytoplasmic streaming

Answer 19

a circular flow of cytoplasm within cells. This movement speeds the movement of organelles and the distribution of materials within the cell.

Question 20

Intermediate filaments have

Answer 20

larger diameter than micro filaments but smaller than that of microtubules

Question 21

Cell wall

Answer 21

is an extracellular structure of plant cells

Question 22

The cell wall distinguishes between

Answer 22

plant and animals cells

Question 23

The cell wall protects

Answer 23

the plant cell, maintains its shape, prevents excessive uptake of water

Question 24

plasmadesmata

Answer 24

channels that connect cells

Question 25

Intermediate filaments are

Answer 25

fibrous proteins coiled into cables, they maintain cell shape (tension baring elements), anchorage of nucleus and certain other organelles, formation of nuclear lamina

Question 26

a motor protein called dynein

Answer 26

drives the bending movements of cilium/flagellum

Question 27

ATP is used for the movement of

Answer 27

dynein proteins between microtubules so that the microtubules can move together