Cellular Organelles

Question 1

What does an iodine stain detect?

Answer 1

Starch

Question 2

What is used to detect mitochondria?

Answer 2

A biochemical assay using tetrazolium dye

Question 3

What is sub-cellular fractionation used for?

Answer 3

To purify sub-cellular components to seperate components by mass.

Question 4

What is differential centrifugation?

Answer 4

Creating fractions for different sized organelles in a solution.

Question 5

What proves there are starch granules in a certain fraction?

Answer 5

Microscopic evidence and a positive iodine reaction

Question 6

What indicates the presence of mitochondria?

Answer 6

A bright red colour

Question 7

Does sub-cellular fractionation yield pure fractions?

Answer 7

No: because there were other organelles present.

Question 8

What is found on the 1st fraction (debris on cheese cloth)?

Answer 8

Cell wall and chloroplasts

Question 9

What’s found on the 2nd fraction (pellet 1)?

Answer 9

Starch granules

Question 10

What’s found in the 2nd fraction (pellet 2)?

Answer 10

Starch and chloroplasts

Question 11

What was found in the supernatant (last fraction)?

Answer 11

Mitochondria