Unit 1: Cells and proteins KA1.1: Laboratory techniques for biologists

Question 1

what are some hazards that might be encountered in the lab

Answer 1

-toxic chemicals
-corrosive chemicals
-heat and flammable substances
-pathogenic organisms
-mechanical equipment

Question 2

name 3 kinds of control measures that could be used in the lab

Answer 2

-appropriate handling and disposal techniques
-protective clothing and equipment (PPE)
-aseptic technique in microbiology

Question 3

what is the purpose of a risk assessment

Answer 3

to outline all the hazards and possible control methods to minimise the risk

Question 4

what is a linear dilution

Answer 4

dilutions that differ by an equal interval

Question 5

what is a log dilution

Answer 5

dilutions that differ by constant proportion

Question 6

what is colorimetry used for

Answer 6

finds the concentration of a known solute in a coloured solution or the turbidity

Question 7

what is the equipment used in a colorimetry experiment

Answer 7

colourimeter, curvette and coloured solution

Question 8

what is the set up for a colourimetry experiment

Answer 8

-pick wavelength of light most absorbed by the colour of the solution (opposite on colour wheel).
-machine needs to be calibrated using a blank of only the solvent baseline (negative control)

Question 9

what is a colourimetry experiment goof for

Answer 9

estimating the density of cells or estimating the concentration of solutions

Question 10

define the term buffer

Answer 10

a solution where adding acids or alkalis have a very small effects on the pH

Question 11

what does adding a buffer solution allow

Answer 11

this allows pH in a reaction mixture to be kept constant. this is extremely useful for biological reactions as pH can effect protein and thus the overall reactions