Lec 17

Question 1

Centrifugal force

Answer 1

Force of gravity affects the settling rate of particles

Question 2

What cause centrifugal field

Answer 2

Central axis as it is rotating

Question 3

2 type of force

Answer 3

-centripetal force
External force,circular movement,uniform speed,directed towards

-centrifugal force
Opposite direction,directed away

Question 4

What is settling rate

Answer 4

How fast it takes for particles to settle

• higher the centrifugal force,higher the settling rate,faster the separation of particles

Question 5

4 type of lab centrifuges

Answer 5

1)low speed table top(3000rpm,clinic,no bio molecule,variable speed,quiet and shutoff on time,pellet cell)

2)High speed centrifuge(chamber refrigerated,25 000rpm,bio molecule can,flexible range of volume,any size,pellet cell nuclei)

3)micro-centrifuge(14000rpm,high speed for small sample,doesn’t slip even at high speed,protein/acid)

4)ultra centrifuge (greater speed,75000rpm,fractionation bio molecule,need vacuum to reduce friction and heat of rotor

Question 6

2 type of rotor

Answer 6

1)fixed angle
2)swing bucket (rotor speed increase,swing at horizontal position)

Question 7

Factor of centrifuges

Answer 7

-settling rate
-density of solute
-properties of solvent
-interaction solute and solvent

Question 8

2 tubes of rotors

Answer 8

1)balance tube
2)specimen tube

Question 9

Swing bucket vs fixed angle

Answer 9

Swing bucket require longer separation,lower speed,pellet is tightly packed at bottom of tube and allow more samples in one run whereas fixed angle require shorter separation,higher speed,pellet is parked on bottom and on sides of tube and fewer sample at each run