3.1-Methods of studying cells

Question 1

magnification equation

Answer 1

magnification= size of image / size of real object

Question 2

resolution

Answer 2

minimum distance apart that two objects can be in order for them to appear as separate items

Question 3

what is the resolving power of a light microscope?

Answer 3

0.2 micrometers

Question 4

magnification

Answer 4

how many times bigger the image is compared to the object

Question 5

image

Answer 5

appearance of the object when viewed under the microscope

Question 6

what is cell fracination?

Answer 6

process where cells are broken up and different organelles they contain are separated out

Question 7

conditions before cell fractionation can begin and their reasons:

Answer 7

1) cold- to reduce enzyme activity that may break down organelles
2)same water potential as tissue- prevent organelles bursting or shrinking as a result of osmotic gain or loss of water
3) buffered- so pH doesn’t fluctuate

Question 8

2 stages of cell fractionation

Answer 8

Homogenation
Ultracentrifugation

Question 9

what are cells broken up by?

Answer 9

homogeniser- releases organelles from cell
the resultant fluid (homogenate) is then filtered

Question 10

Describe the process of ultracentrifugation

Answer 10

process in which fragments in the filtered homogenate are separated in a machine called a centrifuge- spins tubes of homogenate at very high speed in order to create centrifugal force

Question 11

Name the first 2 heaviest organelles that are released first during the process of ultracentrifugation

Answer 11

nuclei
mitochondria