Analysis of cell components

Question 1

What is the equation for magnification?

Answer 1

Magnification = image / actual

Question 2

How do you get from a mm to a μm? (millimetre to micrometer)

Answer 2

x1000

Question 3

How do you get from a μm to a nm? (micrometer to nanometer)

Answer 3

x1000

Question 4

What is resolution?

Answer 4

How detailed an image is

Question 5

What are the two types of microscope?

Answer 5

Light

Electron

Question 6

What is the magnification of an optical microscope like in comparison to an electron?

Answer 6

Lower at a max of x1500

Electron is a max of x 1 500 000

Question 7

What is the resolution of the optical microscope like in comparison to an electron?

Answer 7

Lower at a max of 0.2μm

Electron is a max of 0.0002μm

Question 8

How do optical microscopes work?

Answer 8

They use light to form an image

Question 9

How do electron microscopes work?

Answer 9

They use electrons to form an image

Question 10

What type of images do electron microscope produce?

Answer 10

Black and white images

Question 11

What are the two types of electron microscopes?

Answer 11

Transmission

Scanning

Question 12

What are advantages of TEMs?

Answer 12

High resolution images

Shows small objects

Question 13

What are disadvantages of TEMs?

Answer 13

Only used on thin specimens

Can only be on non-living specimens done in a vacuum

Question 14

What are advantages of SEMs?

Answer 14

Used on thick specimens

Can be 3D

Question 15

What are disadvantages of SEMs?

Answer 15

Give lower resolution images than TEMs

Can only be on non-living specimens done in a vacuum

Question 16

What is a good way to remember the equation for magnification?

Answer 16

MIA

M=I/A

Question 17

What is cell fractionation?

Answer 17

Separating organelles from the cell

Question 18

What are the three stages of cell fractionation?

Answer 18

1) Homogenisation
2) Filtration
3) Ultracentrifugation

Question 19

What is homogenisation? (cell fractionation)

Answer 19

Breaking up the cells using a blender

Question 20

What should the solution be in homogenisation?

Answer 20

Ice-cold
Isotonic
Buffered

Question 21

Why should the solution be ice-cold?

Answer 21

to reduce the activity of enzymes that break down organelles

Question 22

Why should the solution be isotonic?

Answer 22

To prevent damage to organelles by osmosis

Question 23

Why should the solution be buffered?

Answer 23

To maintain the pH

Question 24

What is filtration? (cell fractionation)

Answer 24

Filtered to remove any debris tissue so the solution you collect only contains organelles

Question 25

What is ultracentrifugation? (cell fractionation)

Answer 25

• Spinning of the tube containing the organelles at a low speed
• The heaviest organelles go to the bottom and form a thick sediment, the rest form the supernatant
• The supernatant is collected and this is repeated at a higher speed each time until all of the organelles are separated out

Question 26

What is the order the organelles will be collected in cell fractionation?

Answer 26

Nuclei
Chloroplasts
Mitochondria 
Lysosomes 
Endoplasmic reticulum 
Ribosomes