protein sequences 9/24

Question 1

what are site directed mutagenesis and heterologous expression

Answer 1

• site directed mutagenesis: changing one codon and seeing how protein turns out ; amino acid modification
• heterologous expression: expression of a gene in a host organism that does not naturally have that gene

Question 2

what is used for its evolutionary relationships between species

Answer 2

cytochrome c

Question 3

structure/function information can be gained by comparison of what in proteins

Answer 3

invariant (critical), conserved, variable residues

Question 4

what configuration does the peptide group have

Answer 4

• trans configuration
• partial double bond character makes peptide group planar

Question 5

what are the three types of bonds of the peptide backbone

Answer 5

amino (phi; amino to alpha), alpha (psi; alpha to carboxyl), carboxyl (peptide bond)

Question 6

the phi and psi bonds on either side of the alpha carbon can

Answer 6

rotate freely

Question 7

why don’t peptide bonds rotate

Answer 7

resonance

Question 8

what does the peptide backbone act like

Answer 8

chain of plates linked together at swiveling junctions