Polvi lec #13

Question 1

What are the four general functions of the cells cytoskeleton?

Answer 1

stuctural support
transport of materials and organelles with in a cell
contraction and motility
spacial organization
cell divsion

Question 2

All cytoskeleton filaments are formed by what bonds?

Answer 2

weak non covalent bonds

Question 3

What are microtubules?

Answer 3

hollow structures made of tubulin, formed of 13 protofilaments that are aseembles by alternating dimers (a and b)

Question 4

What is the postive end of microtubules? What is the neg end?

Answer 4

positive end is b tubulin
negative end is a tubulin

Question 5

Where are microtubules formed? What is the centrosome compose dof?

Answer 5

at the centrosome, composed of two centrioles thats surrounded by PCM

Question 6

Where do new microtubules grow off of?

Answer 6

The PCM, cause it has the Y-turc (which is made of y tubulin and non tubulin proteins in a ring), only a tublin can start growth here

Question 7

What do centrosomes not dictate?

Answer 7

their stability and rate of assemply of mcrotubules

Question 8

Stability of microtubules is determined by what?

Answer 8

MAPS (links tubulin dimers together), temp, and +TIPS (bind at plus growing end of microtubules)

Question 9

What hydrolyzes GTP? Why is this important?

Answer 9

B-tubulin does, you need this for microtubules assembly