1. which of these is not a feature of a colloid?
- Optical feature: Opalescent
- Can be seen by electric microscope
- Can be separated by electrophoresis because they often carry a charge
- Allows dialysis
- Contributes to the oncotic pressure
- Because of their large size- they can induce light diffusion
- > 500nm
- settles by ultracentrifugation - cannot use filtration
1 of 8
Other questions in this quiz
2. which is not true?
- surfactants are compounds that increase surface tension (adhesive and cohesive forces)
- when the monomer conc > CMC then a micelle is formed
- there are 4 types of surfactants - anion, cationic, amphoteric, non ionic
- Thin layer chromatography - separates substances with different affinity to 2 phases (staionary and mobile phase)
3. What is dialysis?
- diffusion of small molecules and ions from the colloid across the dialysation membrane eg cellophane which is permeable to small molecules and not colloid perticlaes
- The removal of waste products from the blood (purpose of an artificial kidney)
- the electrophoretic mobility of the particles depends on the size , ccharge and shape.
4. Which purpose of the gel is correct?
- Silica gel - chromatography, drying
- Agarose gel - electrophoretic separation of protiens
- polyacrylamind gel - electrophoretic separation of nucleic acids
5. what is a protective colloid?
- A stubstance that specifically stabilises emulsions eg glycocholic (facilate absorption of dietary lipids)
- A protective colloid are substances that form a hydrophilic colloid solution stabilizing the hydrophobic colloid particles.
- A protective colloid are substances that form a hydrophobic colloid solution stabilizing the hydrophillic colloid particles.
- proteins in the blood are protective colloids of Calcium phosphate and calcium carbonate leading to its precipitation (forming gall stones)