Isolation Of Chloroplasts Practical

Question 1

What speed can a centrifuge reach

Answer 1

130,000 rpm (revolutions per minute)

Question 2

Method for the practical

Answer 2

Finely chop about 5g of spinach leaves and grind in a motar with 10ml of buffer solution
Strain the solution through a J-cloth in to a 100ml beaker
Pour the suspension from the beaker in to a centrifuge tube and centrifuge for 10 minutes
Discard the supernatant and add 5ml of buffer to the sediment (containing chloroplasts) and mix gently with a glass stirring rod
Place a drop of the resultant suspension on a slide and view under a microscope

Question 3

What equipment do you need for this practical

Answer 3

5g of spinach leaves
Pestle and mortar
B
Buffer solution
J-cloth
100ml beaker
Centrifuge
Centrifuge tube
Glass stirring rod
Pippette

Question 4

Structure of chloroplasts

Answer 4

Contain chlorophyll which gives the plants their green colour
Have a double outer membrane
Thylakoid membrane allows substances in and out of the chloroplast
Thylakoid appears in stacks called ‘grana’ which contain the chlorophyll
Stroma is fluid filled

Question 5

Function of chloroplasts

Answer 5

Absorbs sunlight
Energy is used during the bio mechanical process of photosynthesis

Question 6

Where do the organelles go in the test tube after centrifugation

Answer 6

Heavier organelles are forced to the bottom of the tube
Lighter organelles move towards the top

Question 7

What are examples of heavy organelles

Answer 7

Nuclei, chloroplasts and mitochondria

Question 8

What is an example of a light organelle

Answer 8

Ribosomes