Cytoskeleton

Question 1

Microfilament morphology

Answer 1

5-7 nanometers in diameter

double helix-ish

polar/assymetric - one end is different chemically, biologically, and physicially from other end

n terminus and c terminus

Question 2

microfilament molecular structure

Answer 2

Actin globular protein subunit

actin binding proteins bing subunits and determine specific functions/assembly

Question 3

filamen

Answer 3

forms crosslink of microfilaments in the plasma membrane

Question 4

microfilaments require what molecule to assemble?

Answer 4

ATP

Question 5

Which end of microfilament has high binding

Answer 5

+ end

ATP can bind to the plus end

Question 6

which end of microfilament has low binding

Answer 6

• end

Question 7

actin related proteins (ARP)

Answer 7

actin branching proteins

Question 8

formin

Answer 8

recruits new actin subunits for rapid growth of actin filaments

Question 9

Functions of microfilaments

Answer 9

cell division

cell adhesion (adherans)

microvilli (increased surface area - **plus end on top)

Question 10

microtubule molecular structure

Answer 10

Tubulin alpha/beta heterodimer subunits (alpha and beta)

24nm

13 protofilaments (

Question 11

microtubule structure/function depends on which molecule?

Answer 11

GTP/GDP

Question 12

The alpha subunit of microtubules is always bound to ___?

Answer 12

GTP

Question 13

the beta subunit of microtubules is bound to ___?

Answer 13

either GTP or GDP and the strucutre/function of the microtubule depends on which

Question 14

which part of the microtubule interacts with any proteins?

Answer 14

carboxyl terminal

everything else is buried within the structure of the tube itself

Question 15

what stabilizes the - end of microtubules?

Answer 15

gamma tubulin ring complexes - centriole???

Question 16

Centriole

Answer 16

9 triplet ring with two triplets in the center

Question 17

what makes cilia move?

Answer 17

dynein motors

Question 18

kinesins

Answer 18

motor protein that walks from - to + end of microtubules

towards plasma membrane

tall

moves using ATPase activity

Question 19

dyneins

Answer 19

motor protein that walks from + to - end of microtubules

towards nucleus

clumpy not tall

also moves using ATPase activity

Question 20

Intermediate filament structure

Answer 20

8-10nm

alpha helices that are supercoiled, made up of different proteins strung together

symmetric/nonpolar

Question 21

4 types of intermediate filaments

Answer 21

1. keratins
2. vimentin/desmin/glial
3. neurofilaments
4. nuclear lamins

Question 22

intermediate filament function

Answer 22

Permanent (not dynamic)

provide structural support - resist mechanical stress