U4 Analytical techniques & Chemical synthesis & Macromolecules Flashcards
What is size exclusion chromatgraphy?
Long column of the stationery phase of pores. Usually gel of specific sizes. Molecules fall from the top to the bottom. Separates proteins based on size.
Larger molecules don’t get trapped and pass quickly.
Small take time to get thru.
What is gel electrophoresis?
Separates proteins based on charge and/or mass. Proteins move through gel in the presence of electric field. One positive to one negative charged. More highly charged moves faster.
SDS-PAGE
Proteins mixed with sodium didecly sulfate to disrupt native charge. All proteins will have similar charge. Proteins will move through gel depending on size. Distance travelled can be related to bands of known proteins. Proteins with less mass moves further.
What is mass spectrometry?
Molecules bombarded to make t lose one electron. Forms radical and molecular ion with +1 charge. Only charged molecules will be measured by device. Mass recorded by the detector. Molecule can be split into two ways. AB -> A+ , B
AB-> A, B+.
Divide molecular peak by 13 for max number of carbons.
What is molecular peak and base peak?
Molecular peak is the heaviest molecule in the mass spectroscopy. Usually the molecule itself. Base peak is the highest peak, most abundance.
What isoelectric point?
pI. Used in Ion exchange. The pH at which a molecule carries no net charge. (Protein)
What is the ion exchange chromatgraphy?
Separates proteins based on pI, isoleectric point pH.
If pH of surrounding buffer > pI, protein is negative charge, anion resin
pI > Buffer, protein positive charge, cation resin.
Infrared spectroscopy? Transmittance?
All moelcules stretch and bend. Infrared light sent to molecule. Amount of light absorbed shows bond types, angles etc. Transmittance is the ratio of light sent to molecule : light produced. Low = more absorbed. Cross reference low transmittance peaks to data booklet.
What phases of elements constitute stationery phase vs mobile phase?
Stationery phase - solid or liquid
Mobile phase - Liquid or gas
What is TLC chromatography?
Sample placed on absorbant stationery phase and moves towards the solvent liquid mobile phase. Shows what it is attracted to. If moves further, than it is attached to solvent, polar (like dissolves in like). if it moves slow, more attracted to stationery phase. (can be non-polar e.g)
What is Column chromatography?
Column with mobile liquid phase at the top, solid stationary phase like thing filled in the column. The samples moves down through the stationary phase. The quicker it flows, the less interactions with stationery phase, less solubility etc. (Relate back to polar vs non-polar) At the top, then more strongly absorbed to stationery.
Describe the Haber process using reaction equations & conditions.
Haber process is the production of NH3.
High pressure 200atm and High temp 400-500C. Catalyst required.
High pressure increases yield, high temp needed to increase rate of reaction.
N2 + 3H2 –> 2NH3
Describe the contact process using reaction equations & conditions.
The contact process is the production of H2SO4 sulfuric acid.
1. Sulfur burnt. S(s) + O2 –> SO2 (g)
2. Reacts with O2 to form trioxide. SO2 + O2 –> 2SO3 (g). V2O5 vanadium oxide catalyst. 400-500C, 1-2 atm.
3. Create oleum by mixing trioxide into sulfuric acid. SO3 + H2SO4(l) –> H2S2O7 (l)
4. Oleum reacts with water to form sulfuric acid. H2S2O7 (l) + H2O -> 2H2SO4 (l)
How is biofuel produced?
Produced via transesterification. Ester and alcohol produces new ester and new alcohol. Produced via base-catalysed and lipase-catalysed methods.
Triglyceride + 3Methanol –> Mixture of fatty acids + Glycerol.
The functional group of the alcohol moves to the ester. CH3 of methanol moves to displaces with CH of fatty acids. Since CH moves to methanol, it makes glycerol.
Under base-catalysed. A strong base is used as a catalyst, incl NaOH, and KOH. 60-70C, atmospheric pressures. Higher Yield, Cheaper
Under lipase-catalysed. Lipase is used (an enzyme that catalyses the hydrolysis of lipids), Lower yield, better purity biofuel
Explain the fermentation of ethanol
Sugar products pulverised with water, which then with enzymes undergo saccharification to form soluble sugars. This is decomposed by yeast to form co2 and ethanol. E.G glucose
C6H12O6 –> 2C2HO + CO2
Explain the hydration method to form ethanol.
All are under 300C 70atm with phosphoric acid catalyst.
1. Phosphoric acid protonates the ethene. (Makes it a single bond and gives +, and gives a H+)
2. Water molecule attaches itself to + charge.
3. The initial hydrogen ion is lost and the + charge. Therefore it remains a catalyst.
