Biological tests - biochemistry

?
  • Created by: HeHeHe24
  • Created on: 06-12-19 16:36
View mindmap
  • Biological tests
    • Iodine
      • few drops into sample
      • blue black
        • starch present
    • Emulsion test
      • sample mixed with ethanol and water
      • cloudy white emulsion
      • lipids present
    • Reducing sugar (glucose)
      • Benedicts test
      • add Benedict's reagent
      • heat in a water bath
      • green - low conc.
        • Colour change
      • red - high conc.
        • Colour change
    • Non reducing sugar (sucrose)
      • warm with dilute HCl
        • neutralises
      • add equal volume of Benedict's reagent
        • warm in a water bath
      • colour change
        • green - low conc.
        • red - high conc.
    • Biruet test
      • tests for peptide bonds
      • mix with 1% NaOH and 1% CuSO4
      • violet coloured complex forms with Cu2+
        • due to alkaline conditions
    • Calorimetry
      • measures transmission/absorption of light in a coloured solution
      • more conc = less light transmitted
      • plot a calibration curve
        • absorbance against conc.
        • find conc. of an unknown solution
    • Chromatography
      • separates mixture into its constituents
      • stationary phase
        • TLC plate or chromatography paper
      • Mobile phase
        • solvent
      • movement depends on polarity and solubility
        • highly polar adsorbs to surface
          • moves slower & travels less
        • due to exposed OH groups being able to form Hydrogen bonds
        • identify
          • calculate Rf values and compare to known
      • solutions that make spot visible
        • UV
          • chemicals fluoresce
          • plate glows except where spots travel
        • Ninhydrin
          • binds to amino acids
          • put in oven so it can bind
        • Iodine
          • enclose dry plate with a few crystals
          • hold to warm
          • vapour forms that can bind to molecules in spots
      • Uses
        • Monitor reactions
        • analyse drugs for purity
        • drugs testing

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules, organic chemistry and biochemistry resources »