click below
click below
Normal Size Small Size show me how
UKCD Biochem Lec 3
terms from Biochem lecture 3
Question | Answer |
---|---|
Assay | investigative procedure for qualitatively assessing or quantitatively measuring the presence or amount or the functional activity of a target entity (the analyte) which can be a drug or biochemical substance or a cell in an organism or organic sample. |
Homogenate | a tissue that is or has been made homogenous, as by grinding cells into a creamy consistency for laboratory studies. A homogenate usually lacks cell structure. Also called broken cell preparation. |
Supernatant | Denoting the liquid lying above a solid residue after crystallization, precipitation, centrifugation, or other process. |
Dialysis | separation of small molecules ex salt ions using semipermeable membrane, molecules larger than pores (protein) stay on top and small molecules (salt ions) diffuse pores, takes advantage of molecules move along concentration gradient from low to high |
Ion Exchange | (charge separation) exchange of ions b/w 2 electrolytes/electrolyte solution and complex, denotes processes of purification/ separation/decontamination of aqueous/other ion-containing solutions w/ solid polymeric/ mineralic 'ion exchangers' |
Affinity Chromatography | method of separating biochemical mixtures, based on highly specific interaction interaction of a molecule or protein to another protein, used in the purification of recombinant proteins. Advantage-you can purify to homogeneity a protein in a single step. |
Electrophoresis | is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field |
Svedberg Units (s) | The force pushing on a particle is proportional to its mass, w/ heavier particles move away from the center of the rotor faster. Particle sedimentation is measured in terms of sedimentation coefficients, or Svedberg units (S), with 1 Svedberg (S) |
Gradient Centrifugation | density gradient solution is prepared, ex range of [sucrose], then spun in ultracentrifuge, fractions collected from top/ bottom of tube. used to determine mass of protein (relative to standards), more accurate than SDS-PAGE. |
Mass Spectrometry | analytical technique that ionizes chemical compounds to generate charged molecules/fragments and then measures mass-to-charge ratio of charged particles, used for determining masses/elemental composition/elucidating chemical structure of particles |
MALDI-TOF | (matrix-assisted laser desorption-ionization, time of flight), sample (suspended in gel matrix) is simultaneously vaporized/ionized by laser, charged proteins accelerated in electric field fly down flight tube, hit detector, smaller ions-faster-first |
Antibody | protein synthesized by animal in response to presence of a foreign substance (antigen), bind to their antigens with high specificity, a characteristic that has made them vital tools in the laboratory. |
Epitope | part of the antigen recognized by the antibody |
Monoclonal | A monoclonal antibody is an isolated, single type of antibody that can be purified from a hybridoma line, and is directed against a single epitope. |
Polyclonal | A polyclonal antibody contains a mixture of different antibodies that can target more than one epitope on the target antigen |
Primary Antibody | antibodies raised against antigenic target of interest, typically unconjugated, recognize/ bind w/ high affinity/specificity to unique epitopes, can be monoclonal and/or polyclonal, measure changes in levels/ specificity of modification |
Secondary Antibody | antibody binds to primary antibodies/ fragments, typically labeled w/ probes for detection/purification/ cell sorting applications, may be polyclonal or monoclonal, available w/ specificity for whole Ig molecules or antibody fragments |
ELISA | Enzyme-linked immunosorbent assay, detect presence of substance (antigen) in liquid sample by detecting presence in wells/ strips/ cap gels, performed indirectly in patient’s serum (ex HIV test) or urine (ex pregnancy test) use monoclonal /polyclonal |
X-Ray Crystallography | method of determining arrangement of atoms w/in crystal, beam of X-ray strikes-nlight spreads into many directions, angles/ intensities produce 3-D picture of density of electrons, mean positions of atoms in crystal/chemical bonds/ disorder determined |