L6 - Separating Organelles

Question 1

what are the 3 stages?

Answer 1

1. homogenisation
2. flirtation
3. ultracentrifugation

Question 2

stage 1

what is homogenisation?

Answer 2

where the cell is broken open to release the organelles

Question 3

stage 1

what ways can you do homogenisation?

(4)

Answer 3

Vibration - e.g. using ultrasound

Grinding using a blender

Detergent solution disrupts the lipid cell membrane

Forcing through a small gap

Question 4

stage 1 - homogenisation

what conditions need to be controlled?

(3)

Answer 4

ice cold temperature

isotonic conditions

buffer solution

Question 5

stage 1 - homogenisation

why do certain conditions need to be controlled?

Answer 5

to prevent damage to the organelles

Question 6

stage 1 - homogenisation

why is an ice cold temp needed?

Answer 6

to reduce any enzyme activity that would break down the organelles

Question 7

stage 1 - homogenisation

why are isotonic conditions needed?

Answer 7

the water potential of the solution should be the same as the organelles to prevent disruption by osmosis

Question 8

stage 1 - homogenisation

why do buffer solutions need to be controlled?

Answer 8

this maintains the pH to avoid damage to the organelles

Question 9

stage 2

what is filtration?

Answer 9

Filtering the homogenate removes any whole cells and tissue debris

Question 10

stage 3

what is ultracentrifugation?

Answer 10

The filtrate can then be put in a centrifuge to separate the organelles depending on their mass

Question 11

in what order do the organelles separate out in?

Answer 11

nuclei
chloroplasts
mitochondria
lysosomes
endoplasmic rectillium (ER)
ribosomes