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6. The amino acids with 'acidic R groups' are characterised by?

  • the AA's aspartate and glutamate. The negatively charged side chains can form electrostatic interactions with positively charged basic side chains.
  • side chains with a positive physiological pH
  • the AA's lysine and arginine. The negatively charged side chains can form electrostatic interactions with positively charged basic side chains
  • side chains with a negative physiological pH

7. Desmosine is an AA...

  • formed of four glycine residues
  • formed of four lysine residues
  • formed of four hydroxyproline residues
  • formed of four hydroxylysine residues
  • formed of four hydroxyproline and hydroxylysine residues

8. The AA's hydroxyproline and hydroxylysine...

  • are hydroxylated forms of proline and lysine, which require vit C as an enzyme cofactor for the synthesis and are found at high levels in collagen
  • are hydroxylated forms of proline and lysine, which require vit C as an enzyme cofactor for their synthesis
  • are hydroxylated forms of proline and lysine, thus not encoded by the genetic code
  • are translated from specific DNA sequences

9. The AA with aromatic R groups are characterised by:

  • an aromatic ring structure which gives these AA their characteristic UV spectra
  • a strong flagrance, as referred to by aromatic
  • a high carbon content
  • an aromatic ring structures

10. Proline:

  • Commonly found in beta turns
  • is an uncommon AA
  • commonly found in alpha helices
  • always hydroxylated to hydroxyproline
  • never found in collagen

11. The AA with 'non-polar' aliphatic R groups are characterised by:

  • high levels of acidic or basic groups
  • high levels of carbon and oxygen atoms in the side chain
  • high levels of carbon and hydrogen in the side chain
  • high levels of hydrogen bonding between carbon and hydrogen atoms in the side chain

12. The amino acids with 'basic R groups' are characterised by:

  • The AA's arginine and leucine which both have positively charged side chains at neutral pH
  • The AA's arginine and leucine with both have a negatively charged side chain and neutral pH
  • May contain histidine, which has a side chain that is always positively charged at physiological pH
  • A negative charge at physiological pH