Cytoskeleton

Question 1

3 major functions of the cytoskeleton

Answer 1

Movement, structural support, cell shape

Question 2

What are microfilaments made of?

Answer 2

Actin

Question 3

In what cells are intermediate filaments found?

Answer 3

Animal cells

Question 4

Which of microfilament, intermediate filaments and microtubules are polar?

Answer 4

microfilaments and microtubules

Question 5

What functions do intermediate filaments provide?

Answer 5

structural support + maintenance of cell and nucleus shape

Question 6

What do intermediate filaments lack that the other 2 have?

Answer 6

Motor proteins

Question 7

What is tubulin?

Answer 7

An alpha-beta heterodimer protein

Question 8

How many protofilaments make up microtubules?

Answer 8

13

Question 9

Is alpha or beta tubulin at plus end of microtubule?

Answer 9

beta as can hydrolyse GTP so is more dynamic

Question 10

What is importance of GTP cap?

Answer 10

Stops dissociation of protofilaments and allows new subunits to join

Question 11

When do microtubules grow?

Answer 11

When polymeristaion rate exceeds hydrolysis

Question 12

What does gamma tubulin bind to?

Answer 12

Alpha tubulin and intracellular organnelles

Question 13

Where microtubules originate from in interphase animal cells?

Answer 13

Centrosome

Question 14

Why is microtubule dynamic instability important?

Answer 14

provides a way for cell to explore and sense changes

Question 15

How much does 1x 8nm kinesin step cost?

Answer 15

1 ATP

Question 16

How many more times rigid are microtubles than microfilaments?

Answer 16

150

Question 17

What is the name fro the part of cilia that extrudes from the cell?

Answer 17

Axoneme

Question 18

What protein complex has 3 motor heads and causes motion waveform in cilia?

Answer 18

Ciliary dynein

Question 19

What are the 2 functions of cilia and flagella?

Answer 19

motility and sensing

Question 20

Length and number of monomers in actin microfilament helix repeat

Answer 20

37nm and 13 monomers

Question 21

What is term used for Actin dynamics?

Answer 21

Treadmilling

Question 22

Primary function of actin microfilaments in plants ad fungi?

Answer 22

pathway for organelle movement

Question 23

Primary function of actin microfilaments in animals?

Answer 23

cell shape and motility

Question 24

What motor proteins are used in plants on actin filaments?

Answer 24

Myosin

Question 25

Name for dramatic conformational change during myosin walking?

Answer 25

Power stroke

Question 26

What do actin and myosin-II form IN ANIMALS?

Answer 26

Contractile arrays

Question 27

What causes cytokinesis?

Answer 27

Contracile ring- actin and myosin II

Question 28

What are most developmental genes involved in?

Answer 28

control of transcription and intercellular signalling

Question 29

What are the devlopmental toolkit genes?

Answer 29

Hox, MyoD, FGF, Wnt, Bmp

Question 30

Hat does Wnt control in devlopment?

Answer 30

AP axis (cniderian- aboral-oral axis)

Question 31

What is interesting about Bmp between deuterosomes and protosomes?

Answer 31

DV axis inversion- nervous system on opposing sides

Question 32

What is colinearity?

Answer 32

order of genes in cluster on chromosome same as order of expression along axis

Question 33

Give an example of colinearity

Answer 33

HOX genes

Question 34

What is tandem duplication?

Answer 34

another copy of gene next to original on chromosome

Question 35

What is the homeodomain?

Answer 35

DNA binding domain HOX genes have