3.1 method of studying cells

Question 1

what affects the resolution of microscopes?

Answer 1

wavelength

Question 2

do electrons or light have a shorter wavelength? what does it do?

Answer 2

• electron, higher magnification

Question 3

what suspense solution is needed for cell fractionation? why?

Answer 3

1- cold
- reduce enzyme activity

2- same water potential
- prevent organelles from bursting / shrinking / osmotic movement

3- buffered
so that pH doesn’t fluctuate

Question 4

describe the process of homogenisation.

Answer 4

cells are broken up in the homogeniser and organelles are released from the cell. the homogenate is then filtered

Question 5

describe the process of ultracentrifugation.

Answer 5

1) filtrate is spun at low speed
2) heaviest organelle (nuclei) forced to bottom
3) supernatent is removed and leaving the sediment
4) supernatent spun at a faster speed for longer -> next heaviest organelle (mitochondria) forced to bottom