Cell Motility-MT

Question 1

Cell motility

Answer 1

Movement of cell
Movement environment
Movement component of cell

Question 2

Motility occur at —,—,— level

Answer 2

Tissue
Cellular
Subcellular

Question 3

MT and MF provide scaffold for

Answer 3

Motor protein
Mechanoemzymes
To produce motion at molecular level

Question 4

MT intracellular movement

Answer 4

Mitotic spindle in separation of chromosomes

Question 5

Cell contractility

Answer 5

Shortening of muscle cells, specialized form of motility

Question 6

Two eukaryotic motility system

Answer 6

1-MT and Motor protein kinesins and dyenins
2-Interactions between actin MF and myosin motor proteins

Question 7

Motor proteins convert

Answer 7

Chemical energy (ATP) into mechanical energy (force)

Question 8

Molecular proteins

Answer 8

Move unidirectionally along cytoskeletal components

Question 9

No motor protein associated with

Answer 9

IF

Question 10

Motors undergo

Answer 10

Cycle ATP hydrolysis, release ADP, acquisition of new ATP

Question 11

Motor protein transduce changes in shape to

Answer 11

Movement of filaments

Question 12

Motor protein are subjected to

Answer 12

Tremendous friction
Stop when energy runs out

Question 13

Motor are processive

Answer 13

Move for significant distances
Until energy runs out

Question 14

Kinesin

Answer 14

Anterograde MT motor

Question 15

Dynenin

Answer 15

Retrograde MT motor

Question 16

Dyenin has —— than kinesin don’t have

Answer 16

Extra dota lule tor

Question 17

MT provide

Answer 17

Rigid set of tracks for transport

Question 18

Traffic toward - end

Answer 18

Inbound

Question 19

Traffic toward + end

Answer 19

Outbound

Question 20

Movement vesicles and organelle along MT

Answer 20

Fast axonal transport

Question 21

Motors are responsible for

Answer 21

Organelle transport and correct localization

Question 22

Two proteins responsible for fast axonal transport

Answer 22

Kinesin I: ATP-dependent transport toward plus end called anterograde
Cytoplasmic dyenin: move cargo toward minus end called retrograde

Question 23

Kinesins movement is coupled to

Answer 23

ATP hydrolysis

Question 24

Kinesin 1 is tetramer

Answer 24

2 heavy chains
2 light chains

Question 25

Kinesin 1 has four region

Answer 25

-globular head region: ATP hydrolyzing engine -neck region: attach head to stalk -coiled helical stalk region: provide flexibility -light chain region: attach kinesin to proteins

Question 26

KRP head

Answer 26

Evolutionarily conserved Similar motor function

Question 27

KRP tail

Answer 27

Highly divergent (Reflecting the cargo diversity)

Question 28

All kinesin have

Answer 28

Motor domains

Question 29

Kinesins are classified based on

Answer 29

Structure

Question 30

Some kinesins from —— some ——

Answer 30

Homodimer Heterodimer

Question 31

Family —— is minus end directed

Answer 31

Kinesin 14

Question 32

Kinesin mode of movement ( hand-over-hand)

Answer 32

1- leading heavy chain bind ATP 2- ATP binding causes conformational change (trailing heavy chain swing forward) 3- trailing heavy chain find new MT binding site and release ADP 4- new trailing head hydrolyze atp to adp and p

Question 33

Dyneins

Answer 33

**Cytoplasmic dyneins**: high processivity toward minus end Dynein doesn’t directly interact with cargo: requires adaptor molecule: dynactin and spectirin **axonemal Dyneins**: generate motility in cilia (power stroke)

Question 34

Kinesin and dynein

Answer 34

Move similar materials inopposite direction over same railway Organelles may bind kinesin and dynein spontaneously

Question 35

Cilia

Answer 35

-Most cell have one to many cilia -Both unicellular and multicellular eukaryotes -Generate a force perpendicular ti cilium

Question 36

Cilia kinds

Answer 36

Motile cilia: move fluid through tracts Non-motile: cilia having sensory functions

Question 37

Flagella

Answer 37

- move cell through fluid environment - same diameter but much longer than cilia - one or few per cell - force generated parallel to flagellum

Question 38

Cilium/flagella share common structure

Answer 38

Axoneme

Question 39

Cilium/flagellum emrge from ——

Answer 39

Basal body

Question 40

Between axoneme and basal body

Answer 40

Transition zone

Question 41

Transition zone

Answer 41

MT begin characteristic of axoneme

Question 42

Axoneme

Answer 42

Nine peripheral MT doublets surrounding central pair of single MT

Question 43

Each MT doublet

Answer 43

One 13 subunit One 10-11 subunit

Question 44

Central tubes in axoneme are enclosed by

Answer 44

Sheath connected to peripheral doublets

Question 45

Doublets are connected to each other by

Answer 45

**nexin** Elastic protein based link

Question 46

Axonemal dyneins

Answer 46

Project from A MT Pair of arms — inner and outer

Question 47

Assembly and dis’s assembly of cilium and flagellum required

Answer 47

Transport material to and from distal end

Question 48

Movement of structural components called

Answer 48

Intraflagellar transport (IFT) Occurs between peripheral doublet and cell membrane

Question 49

Kinesin-2

Answer 49

(Plus end directed motor) Pulls IFT toward cilium

Question 50

Cytoplasmic dynein

Answer 50

(Minus end directed motor) Return IFT trains to cell body

Question 51

Axonemal dynein

Answer 51

Cause MT sliding within the axoneme allowing cilia and flagella to bend (no change in overall length of MT)

Question 52

Stem axonemal dynein

Answer 52

Tightly anchored to outer surface of A tubule

Question 53

Globular head and stalk of axonemal dynein

Answer 53

Project toward B tubule of neighboring doublet

Question 54

Axonemal dynein

Answer 54

Exert force on neighbouro g Mt pulling A tubule toward minus end **some flexibility but not really moving**

Question 55

Presence of nexin linkage prevent ——

Answer 55

Sliding the doublet past each other

Question 56

At any given time

Answer 56

Axonemal dynein on one side of axoneme are active, while on other side is inactive

Question 57

Primary cilia are used in ——

Answer 57

Sensory structure