Cytoskeletal

Question 1

What makes up tubulin

Answer 1

Alpha and beta

Question 2

What is considered a basic subunit

Answer 2

alpha and beat dimer

Question 3

Are microtubules polar

Answer 3

Yes one side is different then the other

Question 4

What polymerizes microtubules

Answer 4

The subunit

Question 5

How long is a microtubule

Answer 5

25nm diameter up to 100 micrometer long really long

Question 6

How many protofilaments in a microtubular

Answer 6

13

Question 7

It is a perfect tube

Answer 7

No there is seam and they aren’t perfectly lined up

Question 8

How far is it between and alpha and beta dimer

Answer 8

8 nm

Question 9

What subunit can bind to Gtp

Answer 9

A binds permantelty to GTP where B can hydrolyze GTP so it can be bound to GTP or GDP

Question 10

What happens at the protfilament grows

Answer 10

Gtp is hydrolyzed

Question 10

Which side is negative and which side is positive

Answer 10

The alpha side is negative and the beta is the positive side

Question 11

How many protofillaments are in singlets doublets and triplets

Answer 11

Singlets have 13 protofilaments
Double and triplets have one tube with 13 protofilaments and one or two 10 protofilament tubes attached

Question 12

What is found in basal bodies and centrioles

Answer 12

Triplets

Question 13

What type of microtubules do nerve axons have

Answer 13

Cytoplasmic microtubules that transport things

Question 14

True or false the cytoplasm of all cells have microtubules

Answer 14

TRUE

Question 15

What type of microtubules are found in cilia and flagela

Answer 15

Axonemal microtubules

Question 16

What is MTOC

Answer 16

Micro-tubular organizing center which is where microtubular come from

Question 17

What is the main MTOC in most cells

Answer 17

The centrosome

Question 18

What part goes away from the centrsome and what part towards

Answer 18

Negative end goes toward the centrsome where the positive end extends outwards except in a dendrite where it is not continous

Question 19

What is the centrosome

Answer 19

A major but not only MTOC in animal cells

Question 20

What do centrosomes contain

Answer 20

Centrioles

Question 21

Are centrioles in plants

Answer 21

NO

Question 22

What are centrioles

Answer 22

They are triple microtubules that are stable and tend not to polymerase but they allow for polymerization to occur around them

Question 23

What allows microtubulars to polymerize in the centrsome

Answer 23

It is filled with pericentriolar matrix that allows them to polymerazie gamma tubulin and augmin

Question 24

How many triplets are in a ring of a centriole

Answer 24

9

Question 25

What is the gamm tubulin ring complex

Answer 25

It provides nucleating sites for microtubules it provides a nucleus that can grow

Question 26

Which way does gamma tubulin help microtubules grow

Answer 26

away from the centrsome as the negative is sitting in the centrisome with the ring is capped and you can not add anything to the negative end

Question 27

What does augmin do

Answer 27

Can from a branch to a new microtubular

Question 28

What end does polymerization occur at

Answer 28

Preferentially at the plus end

Question 29

When do you have polymerization

Answer 29

When you have an ammount of tubulin that is above critical concentration and a nuclei

Question 30

What end does it depolymerize faster

Answer 30

The positive end it will depolymerize when you below CC

Question 31

What happens if you just have monomers

Answer 31

It will take longer because you have to first grow the nuclei

Question 32

How can you figure out CC

Answer 32

You add monomers and once you reach critical concentration anything above that you will get a filament

Question 33

What temp do microtubules dissaseemble at

Answer 33

4 degrees

Question 34

What are microtubules independent of

Answer 34

Cc if there are lots of dimers they will polymerize and head away from the centriole and move to where there is lees concentration adn dimers is de polymerize

Question 35

What is castrophe

Answer 35

Where depolymerization starts to form it is the peak

Question 36

What is dissasbley

Answer 36

Depolymerization

Question 37

What is rescue

Answer 37

When they start polymerizing again

Question 38

What is oscillations in length is common

Answer 38

Dynamic instability

Question 39

What does dynamic instability depend on

Answer 39

GTP-B tubulin cap because with the GTP can even protofilaments in the center of tubule are stable

Question 40

What happens when GTP to GDP hydrolysis reaches the positive end

Answer 40

it weakens the cohesion between protofilaments and fraying occurs

Question 41

Where does de polymerization occur

Answer 41

The smooth ends fray and it continues towards the positve end

Question 42

what is tubulin away from the positve end

Answer 42

In the GDP form

Question 43

What holds the microtubule together

Answer 43

the y gamma on the negative end and the GTP cap on the other end

Question 44

What does Colchicine do

Answer 44

Depolymerizes

Question 45

What does Taxol do

Answer 45

Stablize they stay the same size you can use this if you want to see what depolymerization does

Question 46

What does MAPs do

Answer 46

Alter microtubular stability

Question 47

What regulates MT spacing

Answer 47

The projection domain can regulate the spacing

Question 48

What about the binding domains of MAP

Answer 48

They are the same

Question 49

What is the projection domain of the microtubules for TAU and MAPS

Answer 49

MAP2 has a long projection domain so they are far apary

Question 50

What are TIPS

Answer 50

The positive end of MT

Question 51

What is EB1

Answer 51

It is a +TIP that binds to unique structures found on growing(+) end and can stabilize and reduce castrophe

Question 52

What is TOG domain

Answer 52

The growing protofillaments

Question 53

What is XMAP215 and CLASP

Answer 53

They can bind to TOG and stabilize protofilaments to prevent catastrophe

Question 54

What is kinesin-13

Answer 54

Regulated by ATP removes terminal dimers causes de pol at end doesnt matter the CC if you have enough it will de pol

Question 55

What is Stathmin

Answer 55

Binds to tubulin dimers in the curve may promote GTP hydrolysis

Question 56

What is stathmin inactivated by

Answer 56

Phosphorylation