2.1.2 Biological Molecules – Chromatography Flashcards
(12 cards)
What piece of scientific equipment can be used to measure the absorbance and/or transparency of a solution?
A colorimeter
When using a colorimeter for the reducing sugar test, which colour filter should be used?
Red
Before each sample is placed in a colorimeter, what should be done?
It should be calibrated to zero using a cuvette filled with water.
Which piece of scientific equipment can be used to test blood glucose levels, hormone levels in urine and protein levels in urine?
A biosensor
How is a biosensor used to check blood glucose?
A drop of blood is placed on the test strip. Any glucose present binds to the enzyme and is broken down. In the transducer, an electrode detects the chemical change and generates an electrical current. The size of the current is proportional to the concentration of glucose
What practical method is used to separate biological molecules?
Chromatography
Name 4 different types of molecules can be separated using chromatography.
- Proteins (and amino acids)
- Carbohydrates
- Vitamins
- Nucleic acids
What is the name and use of TLC?
Thin Layer Chromatography
This is chromatography performed on TLC plate, which is a sheet of plastic or glass coated with silica gel/aluminium hydroxide.
What are the advantages of TLC?
- Is more sensitive
- Gives clearer separation
- Quicker than paper chromatography
Which part of the chromatography is known as the stationary phase?
The chromatogram – this is either chromatography paper or thin layer chromatography plate
Which part of the chromatography is known as the mobile phase?
The solvent (usually water or ethanol)
What is the retention factor formula?
Rf = distance moved by sample / distance moved by the solvent
