Lec8

Question 1

Structure and function of microtubules

Answer 1

Structure thickest. Hollow tubule with globular proteins

Function maintain cell shape
Cell motility in cilia and flagella
Chromatin and organelle movement

Eg 9+2 in cilia and flagella in cells of eukaryotes
A ring of 9 doublets surround a pair of central tubules

Question 2

Structure and function of microfilament

Answer 2

Structure thinnest. Double chain of polymers of actin

Function maintain cell shape
Muscle contraction
Cell devision
Cell motility

Question 3

Structure and function of intermediate filament

Answer 3

Structure. Cables made of fibrous protein Many different shapes

Function. Maintain cell shape
Anchorage
Nuclear lamina

Question 4

How many kinds of Signaling

Answer 4

Direct: cell junction and cell-cell recognition

Secreted signaling molecules :
Local signaling Paracrine signaling and synaptic signaling
Long distance signaling. Testosterone

Question 5

3 stages of signaling

Answer 5

Reception

Transduction Phosphorylation cascade. Amplify one single signal from activated relay molecules with inactivated protein kinase to active protein and function on specific genes

Response

Question 6

Intracelllar receptors and extra ellipse receptors

Answer 6

Intercellular receptors.
Eg testosterone

Receptors activated by hormone binding
Moves to nucleus and activated genes

Extracellular (cell surface receptors)

Question 7

The compounds of cytoskeleton

Answer 7

Microfilament
Microtubule
Intermediate filament