3 Chromatography involving amino acids

 

/
~
~
~
/
Show Learning Materials

3.13 Amino Acids Proteins And Dna Page 4

Oxford Textbook Pages : 464 - 465

CGP Revision Guide Pages : 183

/
/
/
/

Show Specification Ref : 3.3.13.2

/
/
/
/
Show past exam questions

Question 1 / 5

AQA Jan 2010 Paper 4 Q6 areas outside the box will not be scanned for marking the three amino acids shown below were obtained by hydrolysis of a protein h n c cooh h n c cooh h n c cooh ch alanine ch ch ch ch nh valine lysine a i draw the zwitterion of alanine a ii draw the species formed when valine is dissolved in an alkaline solution mark a iii draw the species formed by lysine at low ph mark mark wmp jan chem b draw the two dipeptides formed by the reaction of alanine with valine areas outside the box will not be scanned for marking c name a suitable method by which the mixture of amino acids formed by hydrolysis of the protein can be separated mark marks turn over for the next question turn over wmp jan chem
Show answer

Question 2 / 5

AQA Jan 2011 Paper 4 Q4 do not write outside the box a name compound y hoch ch cooh mark b under suitable conditions molecules of y can react with each other to form a polymer b i draw a section of the polymer showing two repeating units mark b ii name the type of polymerisation involved mark c c i when y is heated an elimination reaction occurs in which one molecule of y loses one molecule of water the organic product formed by this reaction has an absorption at cm in its infrared spectrum identify the bond that causes the absorption at cm in its infrared spectrum mark c ii write the displayed formula for the organic product of this elimination reaction c iii the organic product from part c ii can also be polymerised draw the repeating unit of the polymer formed from this organic product mark mark wmp jan chem do not write outside the box d at room temperature aminobutanoic acid exists as a solid draw the structure of the species present in the solid form e the amino acid glutamic acid is shown below mark draw the structure of the organic species formed when glutamic acid reacts with each of the following e i an excess of sodium hydroxide e ii an excess of methanol in the presence of concentrated sulfuric acid e iii ethanoyl chloride question continues on the next page mark mark mark turn over wmp jan chem do not write outside the box f a tripeptide was heated with hydrochloric acid and a mixture of amino acids was formed this mixture was separated by column chromatography outline briefly why chromatography is able to separate a mixture of compounds practical details are not required marks wmp jan chem turn over for the next question do not write on this page answer in the spaces provided turn over wmp jan chem
Show answer

Question 3 / 5

AQA Jun 2010 Paper 4 Q6 a consider the tripeptide shown below that is formed from three amino acids k l and m do not write outside the box h n ch co nh ch ch ch nh co nh cooh from k from l from m a i name the process by which the tripeptide is split into three amino acids mark a ii give the iupac name for the amino acid k mark a iii draw the structure of the zwitterion of amino acid l a iv draw the structure of the species formed by amino acid m at low ph mark mark wmp jun chem b consider the amino acid serine do not write outside the box h n cooh ch oh b i draw the structure of the product formed when serine reacts with an excess of ch br b ii draw the structure of the dipeptide formed by two molecules of serine mark turn over for the next question mark turn over wmp jun chem
Show answer

Question 4 / 5

AQA Jun 2014 Paper 4 Q6 do not write outside the box lysine and alanine are two amino acids ch h n ch c cooh h c cooh nh lysine nh alanine a give the iupac name of lysine mark b b i draw structures to show the product formed in each case when lysine reacts with an excess of aqueous hcl b ii an excess of aqueous naoh b iii methanol in the presence of a small amount of concentrated h so mark mark mark wmp jun chem do not write outside the box c the mass spectrum of alanine gives a major peak at m z write an equation for the fragmentation of the molecular ion of alanine to give an ion that produces this peak in your answer draw the displayed formula for this fragment ion marks d draw a dipeptide formed from one molecule of lysine and one molecule of alanine mark e the dipeptide in question d is hydrolysed in acid conditions and the mixture produced is analysed by column chromatography the column is packed with a resin which acts as a polar stationary phase suggest why lysine leaves the column after alanine marks turn over wmp jun chem
Show answer

Question 5 / 5

AQA Jun 2016 Paper 4 Q5 do not write outside the box proteins contain sequences of amino acids joined by peptide links amino acid chains polypeptides are attracted to each other by hydrogen bonding a i a section of a protein is formed from one molecule of each of the amino acids glycine h nch cooh and alanine h nch ch cooh add bonds and atoms to the diagram to complete a structural formula for this section of the protein marks a ii draw a diagram to show how an amino acid chain can form a hydrogen bond with another amino acid chain your diagram need only show the relevant atoms from one amino acid in each chain mark wmp jun chem do not write outside the box b leucine serine and glutamic acid are naturally occurring amino acids ch chch nh cooh hoch nh cooh hooc ch nh cooh leucine serine glutamic acid b i give the iupac name of leucine mark b ii draw the structure of the zwitterion of serine b iii draw the structure of the ester formed by two molecules of serine b iv draw the structure of the species formed by glutamic acid at low ph mark mark mark turn over wmp jun chem
Show answer
/
/
/
/
/
/