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Flashcards in Cytoskeleton Deck (95)
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1

what is the cytoskeleton

a network of interconnected filaments and tubules

2

list four functions of the cytoskeleton

cell structure and mechanics
force generation for motility
cell division
intracellular transport

3

what are the three major structural elements making up the cytoskeleton

microtubules, microfilaments and intermediate filaments

4

out of the three major structural elements making up the cytoskeleton which is the largest and which is the smallest

the largest are the microtubules and the smallest are the microfilaments

5

what are the monomers making up the microtubules called

alpha tubulin and beta tubulin

6

how many protofilaments are in the wall of a microtubule

13

7

what is the outer diameter of a microtubule

25nm

8

what is the inner diameter of a microtubule

15nm

9

one end of a microtubule is usually attached to a single microtubule organising centre which is the

centrosome

10

microtubules have a +ve and a -ve end so they are said to have

polarity

11

microfilaments are the thinnest of the three types of fibres, what is the size

7nm

12

what are microfilaments made up of

actin

13

what is the free monomer making up the microfilaments called

g-actin

14

what is the linear polymer making up the microfilaments called

f-actin

15

do microfilaments have polarity

yes, one side is -ve one is +ve

16

what are microfilaments involved in

muscle movement, intracellular transport, maintenance of animal cell shape

17

do intermediate filaments have polarity

no

18

describe the structure of intermediate filaments

eight protofilaments joined end to end with staggered overlaps

19

what is the size of intermediate filaments

8-12nm

20

what are the two types of microtubules

cytoplasmic microtubules and axonemal microtubules

21

list the four functions of the cytoplasmic microtubules

regulation of cell shape, maintaining axons, formation of mitotic spindle and vesicle transport

22

list the two functions of the axonemal microtubules

cell motility and act as a signalling hub

23

what are axonemal microtubules and where are they found

they are organised and stable microtubules found in cilia, flagella and basal bodies - to which cilia and flagella attach

24

microtubules can have different types of microtubules, what are the three

singlet, doublet, triplet

25

how do microtubules form

by the addition of tubulin dimers at their ends

26

what are the three stages of microtubule polymerisation

nucleation, aggregation into oligomers and elongation

27

what charge does the beta end of a microtubule have

positive

28

what charge does the alpha end of a microtubule have

negative

29

describe the nucleation stage of microtubule formation

slow, also called the lag phase

30

describe the elongation phase of microtubule formation

occurs at a faster rate than the lag phase/nucleation,