Unit 1:Key Area 1- Lab Techniques For Biologists

Question 1

What is risk?

Answer 1

Risk is the likelihood of harm arising from exposure to a hazard

Question 2

Give an example of a hazard in a lab

Answer 2

Toxic/corrosive chemicals, heat, flammable substances, pathogenic organisms and mechanical equipment

Question 3

What is the purpose of a risk assessment?

Answer 3

To identify control measure to minimise risk

Question 4

Give an example of a control measure

Answer 4

Appropriate handling techniques, protective clothing/equipment and aseptic technique

Question 5

What is the difference between a linear dilution and a log dilution?

Answer 5

Linear solutions differ by an equal interval and log solutions differ by a constant proportion

Question 6

What is the purpose of plotting measures values for a known concentration to produce a line or curve?

Answer 6

To determine the concentration of an unknown for the standard curve

Question 7

What are the methods and uses of a colorimeter to quantify concentration and turbidity?

Answer 7

Calibration with an appropriate blank as a baseline, use of absorbance to determine concentration of a coloured solution using suitable wavelength filters, use of percentage transmission to determine turbidity, such as cells in suspension

Question 8

What is the use of a centrifuge?

Answer 8

To separate substances of differing densities

Question 9

What is a pellet?

Answer 9

The more dense components separated in a solution after centrifugation

Question 10

What is a supernatant?

Answer 10

The less dense components of a solution separated after centrifugation

Question 11

What can be separated using paper and thin layer chromatography?

Answer 11

Amino acids and sugars

Question 12

The speed that each solute travels along the chromatography depends what?

Answer 12

It’s differing solubility in the solvent used

Question 13

What can be separated in affinity chromatography?

Answer 13

Proteins

Question 14

Describe the process of affinity chromatography

Answer 14

A solid or gel column is created with specific molecules bound to the matrix or gel. Soluble target proteins in a mixture with high affinity for these molecules become attached to them as the mixture passes down the column. Other non target proteins are washed out.

Question 15

What can be separated using gel electrophoresis?

Answer 15

Proteins and nuclei acids

Question 16

Describe the process of gel electrophoresis

Answer 16

Charged macromolecules move through an electric field applied to a gel matrix.

Question 17

What categories do native gels separate proteins by?

Answer 17

Size, shape and charge

Question 18

Do native gels denature the molecule? Why?

Answer 18

No, so that separation is by shape, size and charge