Isf A Lecture 7 Cytoskeleton

Front 1

microfilaments

Back 1

actin is major protein

-somewhat disordered looking meshwork
-polar element
- assemble, rearrange and disassemble during movement

Front 2

myosins

Back 2

acting binding proteins
-force generating enzymes

Front 3

calmodulin

Back 3

calcium ions that are involved in teh calcium dependent regulation of myosin activity

Front 4

microtubles

Back 4

long hollow rods with electron dense walls
- made principally from tublin
- hydrolize GTP NOT ATP
- contain MAPS
- can be polymerized or disassembled as needed
-maintain cell shape
- intracellular movements (organelle movements around the inside of the cell)
- form mitotic spindle

Front 5

tublin

Back 5

dimer composed of two similar but non-identical subunits

Front 6

MAPs

Back 6

Microtubule-associated proteins
-found in microtubles
-may alter stability of polymers in cells and crosslink the microtubles with other cytoskeletal elements

Front 7

MTOC

Back 7

Microtuble organizing centers
-directs microtuble assembly, ex: centrioles of mitotic spindle

Front 8

Saltatory organelle movments

Back 8

mitochondria, lysososmes, secretory granules, and other membrane bound organelles move around inside cells
DEPEND ON MICROTUBULES

Front 9

dynein

Back 9

a motor protein in cells which converts the chemical energy contained in ATP into the mechanical energy of movement. Transports various cellular cargo by "walking" along cytoskeletal microtubules towards the minus-end of the microtubule, which is usually oriented towards the cell center

Front 10

kinesin

Back 10

a motor proton that uses ATP to make mechanical energy and transports cargo in the anterograde direction, towards the positive-end of the microtuble. Which is usually oriented away from the cell center.

Front 11

axoneme

Back 11

9 microtubule doublets, each consisting of a complete and an incomplete microtuble joined togehter. 2 microtubules are found int eh center of the circle

"9+2"

forms core of cilia and flagella

Front 12

cilia

Back 12

microtuble dependent - function to move fluids past the cells

axoneme is the core of cilia

Front 13

flagella

Back 13

dependent on microtubules
- axoneme is core of flagella

-usually one flagella per cell and act to propel a cell through a fluid medium.

Front 14

Intermediate filaments

Back 14

- polymerize to form long chains
- NON POLAR (both microfilaments and microtubles are)
-very diverse structures of cytoskeleton structure and function dictated by protein
- a family of related proteins that share common structural and sequence features. Intermediate filaments have an average diameter of 10 nanometers, which is between that of actin (microfilaments) and microtubules.

- Most Intermediate Filaments are cytoplasmic but lamins are nuclear

Front 15

Keratin

Back 15

intermediate filament
-foudn in hair and epidermal cells - very stable
- when cell needs to get ride of intermediate filaments keratin uses specific preteases to break them down into amino acids.

Front 16

Lamins

Back 16

intermediate filament found on the interior surface of nuclear envelope