Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Advanced Higher Biology > UNIT 1 - lab techniques > Flashcards

UNIT 1 - lab techniques Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is a hazard?

A

a hazard is anything which could cause harm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are some examples of hazards in labs?

A

toxic or corrosive chemicals

heat or flammable substances

pathogenic organisms

mechanical equipment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a risk?

A

a risk is the likelihood of harm being caused by exposure to a hazard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

risk assessment meaning?

A

risk assessment involves identifying control measures to minimise the risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

examples of hazardous substances?

A

corrosive chemicals - sulfuric acid

toxic chemicals - lead ethanoate (can bioaccumulate in the human body and can non competitively inhibit enzymes)

flammable substances - ethanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

examples of hazardous organisms?

A

animals - new zealand flatworm

plants - euphorbia plants release latex when cut that causes inflammation to the skin

microorganisms - e. coli is a common lab bacterium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

examples of hazardous equipment?

A

sharp scalpels

glassware

centrifuge loaded unevenly

gas taps

electrical sockets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are control measures used for?

A

control measures are used to minimise risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the three main categories of control measures?

A

appropriate handling techniques - e.g clamping test tube before heating

protective clothing and equipment - lab goggles

aseptic technique - sterilise with ethanol to prevent exposure to or escape of a pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how are dilutions helpful?

A

dilutions can help with
- controlling confounding variables

  • setting up a suitable range for the independent value
  • making sure the dependent variable can be measured evenly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a pipette?

A

used for accurately measuring out set volumes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is an autopipette?

A

used for very small volumes and has a disposable tip meaning that you can cut down contamination risks when taking samples

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

burettes

A

used to add a small volume in a controlled manner

these are used when calculating an unknown concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a linear dilution?

A

a range of dilutions which differ by equal intervals e.g 0.1m 0.2m 0.3m 0.4m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is good about a linear dilution?

A

allows for less error in measurement since each dilution is made independently of the others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is a log dilution?

A

a range of dilutions that differ by a constant proportion in this, each dilution acts as a stock for the next dilution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens if you make an early error in a log dilution?

A

if you make an early error it is then compounded in later dilutions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is a buffer?

A

they are aqueous solutions that are used in experiments to keep the pH of a reaction constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is a standard curve used for?

A

determining the concentration of an unknown solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how is a standard curve produced?

A

by plotting measured values for known concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is a colourimeter used for?

A

determining the turbidity of a solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how does a colourimeter work?

A

an appropriate blank is used as a baseline.

the measurement of the absorbance is used to calculate the concentration of the coloured solution using suitable wave length filters.

the measurement of percentage transmission is is used to determine turbidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is centrafugation?

A

a technique used to separate substances of differing density. more dense components settle in a pellet; less dense components remain in the supernatant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is affinity chromatography?

A

a separation technique used to separate target proteins from a mixture of proteins. this is done as:

  • the mixture is put down a gel column and the target protein within the mixture becomes attached to the ligands/antibodies.
  • non-target molecules with a weaker affinity pass through the column.
  • the target molecules inside the column are washed out separately and then collected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is gel electrophoresis?

A

a technique that is used to separate proteins and nucleic acids where charged macromolecules move through an electric field applied to a gel matrix

26
Q

what is native gel electrophoresis?

A

this technique separates proteins and nucleic acid based by their shape and size and charge

27
Q

what are toxic chemicals?

A

toxic chemicals are substances that are harmful when inhaled, ingested, injected or absorbed. the degree of toxicity is determined by the concentration of the substance

28
Q

what is a corrosive chemical?

A

a corrosive chemical is a reactive substance that can damage living tissue. they either act directly by chemically destroying part of the body or indirectly by causing inflammation.

29
Q

what do native gels do?

A

native gels do not denature the molecules so the separation is by size, shape and charge

30
Q

what is SDS-PAGE?

A

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

31
Q

what is a proteins isoelectric points?

A

A protein IEP is the pH value which a protein is electrically neutral with surface charges that are balanced. proteins can be separated from a mixture using their IEPs. this is the pH at which a soluble protein has no net charge and will precipitate out of the solution.

This works as proteins that have a pH above the IEP are positive and proteins with a pH lower than the IEP are negative. This allows them to stay suspended in the solution

at IEP the protein loses solubility in water and precipitates out of the solution.

32
Q

what happens if the solution is buffered to a specific pH (IEPs)?

A

if the solution is buffered to a specific pH, only the protein(s) that have an IEP of that pH will precipitate

33
Q

what is a gradient gel used for?

A

soluable proteins can be separated using an electric field and a pH gradient gel

34
Q

when does a protein stop moving through the gel in a gel gradient?

A

when the protein has reached its IEP in the pH gradient because it has no net charge

35
Q

what is an immunoassy?

A

they are techniques that are used to detect and identify specific proteins using stocks of antibodies with the same specificity

36
Q

what are proteins detected by?

A

proteins can be detected using antibodies

37
Q

what are monoclonal antibodies?

A

stocks of antibodies that are specific to a particular antigen

38
Q

what is a chemical label?

A

the label is often a reporter enzyme producing a colour change but chemiluminescence, fluorescence radioactivity and other reporters can be used.

39
Q

what is an antibody specific to the protein antigen linked to?

A

an antibody specific to the protein antigen is linked to the chemical label

40
Q

what can be used to detect the presence of antibodies?

A

in some cases, the assay uses a specific antigen to detect the presence of antibodies

41
Q

what is western blotting?

A

a technique used after SDS-PAGE electrophoresis. this is where separated proteins from the gel are transferred (blotted) onto a solid medium.

42
Q

what are proteins identified by?

A

specific antibodies with reporter enzymes attached

43
Q

what is bright field microscopy used for?

A

this is commonly used to observe the whole organism, parts of an organism, thin sections of dissected tissue or individual cells

44
Q

what is the aseptic technique?

A

procedures in place to prevent contamination including sterilising equipment and working surfaces. this is done by heat or chemical means. it eliminates unwanted microbial contaminants..

45
Q

what is a fluorescence microscopy?

A

it uses UV light to detect specific florescent stains which bind and visualise certain molecules and structures within cell walls/tissues

46
Q

what does the aseptic technique eliminate?

A

contamination and competition

47
Q

how is a microbial culture started?

A

using an inoculum of microbial cells on an agar medium or in a broth with suitable nutrients

48
Q

what is culture media used for?

A

many culture media exist to promote the growth of specific cells and microbes

49
Q

how are animal cells grown?

A

animal cells are grown in medium containing serum with growth factors

50
Q

what are growth factors?

A

growth factors are proteins that promote cell growth proliferation. growth factors are essential for the culture of most animal cells.

51
Q

what are serial dilutions usually used for?

A

serial dilutions are usually used to achieve a suitable colony count

52
Q

what is vital staining required for?

A

vital staining is used to identify and count viable cells. this uses harmless dye to strain either living or dead cells for microscopical observation to allow a viable cell count to be made.

53
Q

what is a haemocytometer used for?

A

they are used to estimate cell numbers in a liquid culture

54
Q

what does plating out a liquid of microbial culture on solid media allow?

A

the number of colony forming units to be counted and the density of cells in culture to be estimated

55
Q

what does v1 c1 = v2 c2 mean?

A

v1 - volume of stock /starting solution
c1 = concentration of stock solution
v2 = volume of diluted solution
c2 = concentration of diluted solution

56
Q

what is western blotting?

A

it is used to identify and locate specific proteins in a sample of tissue homogenate or extract based on their ability to bind to specific antibodies.

57
Q

what is serum?

A

vitally important as a source of growth factors, hormones, lipids and minerals for the culture of cells

58
Q

what is the difference between primary and tumour lines

A

in culture primary cell lines can divide a limited number of times whereas tumour cell lines can preform unlimited devisions.

59
Q

what is paper chromatography?

A
  • it is used to separate amino acids and sugars.
  • it works by adding a spot of the solution to an origin line of a piece of paper or a metal foil strip that has a thin layer of silica/cellulose bound to it.
  • the solute is allowed to run.
  • the speed that each solute runs along the strip/paper depends on the solubility of the solute used and the differing affinity for the paper or thin layer used.
60
Q

what are the steps of western blotting?

A

1) protein is transferred to a membrane by blotting
2) antibodies bind to a protein as the membrane is treated with antibodies specific to a target protein
3) excess is washed away but some antibodies bind specifically to target
4) the second antibody with the radioactive label is added and binds to antibodies present
5) membrane placed against a photographic film with a mark showing where the radioactive label was

Advanced Higher Biology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions