Key Area 1.1

Question 1

List 5 hazards found in biology laboratories

Answer 1

Toxic Chemicals, Corrosive Chemicals, Flammable Chemicals, Pathogens and Mechanical Hazzards

Question 2

Describe what is meant by hazard risk assessment

Answer 2

Involves identifying risk levels and control measures that can be used to minimise these risks

Question 3

Vital staining

Answer 3

required to identify and count viable cells; on dead cells stain dark

Question 4

Haemocytometer

Answer 4

used to estimate cell numbers in a liquid culture

Question 5

serial dilutions

Answer 5

often needed to achieve a suitable colony count

Question 6

in culture, primary cell lines…

Answer 6

can divide a limited number of times whereas tumour cell lines can perform unlimited divisions

Question 7

Animal cells

Answer 7

they are grown in medium containing proteins called growth factors from serum
growth factors are proteins that promote cell growth and proliferation

Question 8

microbial culture

Answer 8

a method of multiplying microorganisms by letting them reproduce in a medium under controlled conditions

Question 9

Aseptic techniques

Answer 9

eliminates unwanted microbial contaminants when culturing microorganisms or cells by sterilisation of equipment and culture media by heat or chemical means

Question 10

Fluorescence microscopy

Answer 10

uses specific fluorescent labels to bind to and visualise certain molecules or structures within cells or tissues

Question 11

Fluorescence microscopy

Answer 11

uses specific fluorescent labels to bind to and visualise certain molecules or structures within cells or tissues

Question 12

Bright-field microscopy

Answer 12

used to observe whole organisms, parts of organisms or thin sections of dissected tissues or individual cells

Question 13

Antigen capture

Answer 13

antibody created container
proteins bind to antibodies
excess washed away
second antibody binds to proteins
visual change indicates presence of desired protein

Question 14

ELISA

Answer 14

a system used to detect specific antigens or antibodies

Question 15

Centrifuge

Answer 15

used to separate substances differing density
more dense settle in the pellet
less dense remain in the supernatant

Question 16

SDS-PAGE

Answer 16

this gives all molecules an equally negative charge and denatures them, separating by size alone

Question 17

Isoelectric point

Answer 17

the pH at which a soluble protein has no net charge and will precipitate out of solution

Question 18

Paper and thin layer chromatography

Answer 18

used to separate different substances such as amino acids and sugars
the speed that each solute travels along the chromatogram depends on its differing solubility in the solvent used

Question 19

Affinity chromatography

Answer 19

a solid matrix or gel column is created with specific molecules bound to the matrix or gel
soluble, target proteins in a mixture with high affinity for the molecules, become attracted to them as the mixture passes down the column
other non-target molecules with a weaker affinity are washed out