amino acids protein and dna

• Why chromatography is used to separate a mixture of amino acids

  • Phase or solvent is mobile
  • amino acids have different Rf values
  • stationary phase is covered in silica
• explain secondary structure in amino acids

  • nitrogen and oxygen are very electronegative
  • therefore C=O and N-H are polar
  • results in hydrogen bond between O and H
  • in which lone pair of electrons on an oxygen atom is strongly attracted to the delta positive H+
• Suggest a way cisplatin is admin

  in very small amounts
• Amino Acids are _____

  amphoteric (they can accept or donate protons)
• At what point will a zwitterion form and what does it depend on.

  The isoelectric point - it depends on the R chain attatched to the amino acid.
• Describe a tertiary structure of protein.

  R group interactions (hydrophilic, ionic, hydrogen bond, disulfide bridge)
• Discuss the use of inhibitors as drugs


  They're hard to make

  Trial and error is used frequently

  harder if chiral!
• Draw cis and trans platin

  like e/z isomeers

  trans: opposite

  cis : above each other

  
• Draw hydrogen bonding between the C and G base pairing

  3 hydrogen bonds between cytosine and guanine

  
• draw hydrogen bonding between A and T base pairing

  2 hydrogen between adenine and thymine

  
• draw two generic amino acids and show how they form peptide links

  2 amino acids from dipeptides with peptide link

  
• Explain how hydrogen bonding between base pairs leads to the two complementary strands of DNA

  A and T both have 2 positions where hydrogen bonding could take place.

  If it was A and C (or G) there would be a 'left' over partially charged atom that would lead to repulsion between A and C for example

  This explains the complimentary base pairings.
• How are scientists speeding up development of new inhibs?

  computer development
• How can we break up proteins? What are the conditions?

  We can use hydrolysis (It's an equilibrium reaction)6 Mol DM-3 HCL Under reflux for 24 hours.
• How do we know if we have a sample of just one amino acid?

  They are chiral, They will therefore rotate P.P.L. display optical isomerism.
• How do we limit the adverse effects of cis platin?


  Target its admisitration to specifically effected areas where possible
• How do we seperate a mixture of amino acids? Why does this work?

  First choose a suitable solventThen place a chromatography plate into it (stationary phase)Then allow the amino acids to travel different up the stationary phaseUse UV light to see where they've got to on the stationary phasecalc R.F. values and compare them to data book values.

  Why does this work?Different R groups leads to different solubility in the same solvent.
• How does Cis Platin work?

  Substitutes its Cl ligands for nitrogen on 2 close by guanine bases in DNA This then kills the cells that are affected by it BECAUSE IT STOPS REPLICATION
• If placed in acidic conditions what happens to an amino acid?

  The NH2 Group will become NH3+
• If placed in basic conditions what happens to an amino acid?

  The COOH group will become COO-
• Name the ONLY anticancer drug

  cisplantin
• state two ways we can see how far amino acids have traveled up a chromatography plate

  UV Light

  Ninhydrin solution on the plate

  iodine vapour
• What 3 things make up a Nucleotide

  phosphate, deoxyribose sugar, nitrogen base
• what affects bonding in proteins

  temp and pH
• inhibitors


  Molecules with a similar shape to the substrate for a given enzyme slide into the Active site and stop catalysis taking place.
• What are the 4 structures of proteins.


  primary, secondary, tertiary, quaternary
• What are the adverse effects of cisplantin specifically?

  Hair loss weakened ammune system liver damage. Must weigh up the benifits and drawbacks
• primary protein structure?


  sequence of amino acids
• secondary structure of protein

  protein structure is formed by folding and twisting of amino acid chain
• What happens if 2 different amino acids are used when polymerisation takes place?

  You form a 'dipeptide' because the amino acid groups can join either way round.
• downside of cisplantin

  affects healthy cells too
• What is a protein

  Poly(peptides) or poly(amides) --> poly(amides) from from diamines and dicarboxylic acids and poly(peptides) come from 2 amino acids
• What is Amino Acid

  A Molecule with COOH and NH2
• What is meant by specificity

  Enzymes only work specific substrates.
• What makes are the 2 common shapes formed in 2º protein structures?

  alpha helix and beta pleated sheet
• What type of bond is formed between the cis platin and DNA?

  dative covalent
• What type of reaction makes proteins?

  condensation polymerisation
• What's a peptide link?


  N-H and C=O next to each other
• What's an enzyme


  biological catalyst
• base pairing in DNA

  Adenine with Thymine

  Cytosine with Guanine