AH Bio 1.1

what is risk?

the likelihood of harm arising from exposure to a hazard

what does a risk assessment help to do?

minimise risk

What does COSHH stand for?

Control of Substances Hazardous to Health

what are some of the substances that COSHH regulation cover?

- chemicals
- products containing chemicals
- fumes
- dust
- vapours and mists
- nanotechnology
- gases and asphyxiating gases
- biological agents

what are 3 control measures?

- appropriate handling techniques
- protective clothing
- aseptic technique

what is a linear dilution series?

A range of dilutions that differ by an equal interval

what is a log dilution series?

a range of different dilutions that differ by a constant proportion

how is a standard curve made?

by plotting the absorbance readings for a series of known concentrations of a substance of culture

what is a buffer?

an aqueous solution that shows very little variation in their pH despite addition of acids or alkalis

what can a colorimeter measure?

- concentration of a pigment in a solution
- turbidity of a liquid
- density of cells in a culture

what is turbidity?

the quality of being cloudy, opaque, or thick with suspended matter.

what quality does centrifugation separate materials according to?

density

what is the liquid fraction at the top of a centrifugation tube called?

supernatant

what can thin layer and paper chromatography be used for?

separating substances such as amino acids and sugars

during thin layer or paper chromatography, what are amino acids separated by?

solubility

what does affinity chromatography separate?

one specific protein from a mixture

what does gel electrophoresis separate?

proteins and nucleic acids

what does gel electrophoresis separate molecules based on?

charge, size, shape

what do charged macromolecules such as proteins or nucleic acids move through?

an electric field

what do native gels preserve?

shape and function of the molecule

what happens to the molecules that pass through SDS-PAGE gels?

they are denatured

what qulity are molecules separated by in SDS-PAGE gels?

size

in SDS-PAGE gels, so smaller or larger molecules travel further?

smaller

how can proteins be separated from a mixture?

isoelectric point

what is the isoelectric point of a protein?

The pH at which a protein is electrically neutral

if the pH is above the IEP what will the charge be?

negative

if the pH is below the IEP what will the charge be?

positive

what happens when a protein reaches its IEP?

it loses solubility in water and precipitates out of solution

what is changed in the solution to allow certain proteins to precipitate?

pH

what can IEP be used in conjunction with?

electrophoresis

when IEP is used with electrophoresis when does a protein stop moving as it travels through a pH gradient?

when it reaches its IEP

what are immunoassay techniques used for?

to detect and identify specific proteins

what are the stocks of antibodies called that are used in immunoassay techniques?

monoclonal antibodies

what are monoclonal antibodies?

antibodies that are identical and will bond to the exact same feature of the antigen

what do monoclonal antibodies have in common?

specificity

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

a chemical 'label'

what is the 'label' normally?

a reporter enzyme

what does the reporter enzyme produce?

a colour change

when is western blotting used?

after SDS-PAGE electrophoresis

what is bright field microscopy used to examine?

whole organisms, parts of organisms, thin sections of disconnected tissue or individual cells

what does fluorescence microscopy use to detect fluorescent stains?

UV light

what does aseptic technique eliminate?

unwanted microbial contaminants

what is the main thing that happens during aseptic technique?

steralisation

how can a microbial culture be started?

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

what is in the medium that used to grow animal cells in?

growth factors from serum

what are growth factors?

proteins that promote cell growth and proliferation

what is a haemocytometer?

a microscopic grid used to estimate cell numbers in a liquid culture

what is vital staining required for?

to identify and count viable cells