All Bio

• Define hazard A potential source of harm
• Hazards include: Toxic or corrosive chemicals Heat or flammable substances Pathogenic organisms Mechanical equipment
• Define risk The likelihood of harm arising from exposure to a hazard
• Risks are considered in terms of: How much harm would exposure to the __________ cause? How much exposure would create ________? hazard, impact
• Control measures for risks include: Appropriate handling techniques Protective clothing and equipment Aseptic Techniques
• What is a risk assessment? A full consideration of all the hazards and the potential risk with controls that can be taken to minimise the risk
• What are linear dilutions? Dilutions that differ by an equal interval
• What are log dilutions Dilutions that differ by a constant proportion
• When are linear dilutions used If you need a sample over a reasonably small range
• When are log dilutions used If you need a sample over a wide range
• What does a colorimeter measure The absorbance/transmission of a solution
• What can absorbance be used to determine The concentration of a coloured solution using suitable wavelength filters
• What can transmission determine Turbidity (e.g. cells in a suspension)
• What is a standard curve? A graph of known concentration against absorbance
• Why use a buffer? It is added to a reaction tube to resist changes in pH
• Why can the addition of a buffer allow the pH of a reacion mixture to be kept constant? The addition of acids or alkalis has very little effect on the pH of a buffer
• How can pH be measured? Indicator or meter
• When separating components, what differences are used to differentiate different parts? Density, Solubulity, Molcule size, Charge and Isoelectric point
• In centrifugation, the separation of components is due to what? density
• In centrifugation, where do more dense components settle in? The pellet
• In centrifugation, where do less dense components settle in? The supernatant
• In chromatography, the separation of mixtures is due to what? Solubility
• In chromatography, do more soluble mixtures move faster or slower than less soluble mixtures? Faster
• In chromatography, do less soluble mixtures move faster or slower than more soluble mixtures? Slower
• In paper chromatography, What is used as the stationary phase and the mobile phase? Paper and solvent
• In thin layer chromatography, what is used as the stationary phase? silica ge/cellulose spread in a thin layer on top of glass
• Affinity Chromatography: 1.A solid matrix is created with ________ molecules bound to the ________ 2._______, target ________ in a mixture, with high ________ for these molecules become attached to them as the mixture passes down the _______ 3. Other non-target _______ with a _______ affinity are washed out specific, matrix Soluble, proteins, affinity,column molecules,weaker
• In gel electrophoresis, charged __________ move through an __________ field applied to a gel ___________ macromolecules, electric, matrix
• In gel electrophoresis, separating proteins are based on what? Size, mass, charge, shape
• In gel electrophoresis, native gels separate proteins based on what? How is this possible? Shape, size and charge They don't denature the molecules
• In gel electrophoresis, SDS-PAGE separates proteins based on what? How is this possible? Size As SDS-PAGE gives all molecules an equally negative charge and denatures them
• What is the iso-electric point The pH at which a protein has no net charge
• At a proteins' IEP, in a buffered solution, it will: Precipitate out of solution Remain stationary in an electric field
• What are immunoassay techniques used for? To detect and identify specific proteins
• Immunoassay techniques use stocks of antibodies with the same specificity, known as...... monoclonal antibodies
• What can the assay use to detect the presence of antibodies? Specific antigens
• The antibody specific to the protein antigen is linked to what? A chemical "label"""
• What is the chemical label often as? A reporter enzyme
• What will the label produce if the antibody binds to the specific protein colour change, chemiluminescence or fluorescence
• Western blotting comes after what? SDS-PAGE Electrophoresis