Unit 1.1 - Laboratory techniques for biologists

Question 1

What is a hazard?

Answer 1

A hazard is anything which could cause harm

Question 2

what is risk?

Answer 2

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

Question 3

What is a linear dilution?

Answer 3

Range of dilutions that differ by equal intervals

Question 4

what is a log dilution?

Answer 4

Range of dilutions that differ by a constant proportion

Question 5

What is a standard curve?

Answer 5

A method used to determine concentration of a solution

Question 6

What are buffers?

Answer 6

solutions that very little change to ph occurs when a small volume of acid or base is added. This allows the ph of a reaction mixture to be kept constant

Question 7

What is a colorimeter?

Answer 7

Equipment used to measure the concentration of a coloured solution or the turbidity (cloudiness).

Question 8

How does a colorimeter work?

Answer 8

It passes a light beam, at a specific wavelength through a cuvette containing a sample

Question 9

How does a centrifuge separate substances?

Answer 9

By density

Question 10

What are the 3 types of chromatography?

Answer 10

Thin Layer chromatography
paper chromatography
affinity chromatography

Question 11

What is chromatography used for?

Answer 11

It allows scientists to identify and or purify the components of a mixture e.g. mixture of amino acids or sugars

Question 12

Paper and thin layer chromatography process

Answer 12

1. A sample of the mixture to be separated is placed on a dot near the bottom of a strip of chromatography paper which is placed in a solvent
2. The solvent moves up through the paper and carries components of the mixture
3. The more soluble components travel the furthest
4. the less soluble travel the least distance

Question 13

How is the process of thin layer chromatography different from paper?

Answer 13

TLC is carried out the same except it is performed on a sheet of glass or plastic which is coated with a thin layer of adsorbent material, usually silica or cellulose

Question 14

What is affinity chromatography used for?

Answer 14

It is used to separate target proteins from a mixture

Question 15

What is the process of Affinity chromatography?

Answer 15

1. A solid matrix or gel column is created with specific molecules bound to the matrix or gel
2. Soluble target proteins with a high affinity for said molecules become attached to them as the mixture passes down the column
3. Other non-target proteins are washed out due to a weak affinity to the molecules
4. The column is washed with specific molecules, due to the high affinity the target proteins will bind and be removed from the column

Question 16

Why can tumour cell lines be maintained in a culture for a long time?

Answer 16

Tumour cell lines can perform unlimited divisions