Lecture 9 (1/2)

Question 1

Peptide Linkage or Peptide Bond is?

Answer 1

the amide formed when amino acids combine through condensation reactions
-The line drawn between a carbonyl group and nitrogen is the bond

Question 2

Constitutional Isomer

Answer 2

Molecules that have the same molecular formula but differ in the way their atoms are connected

Question 3

Glutathione

Answer 3

• biological tripeptide
• formed from glycine (gly), Cysteine (Cys), and glutamic acid (glu)
• Correct order is (glu-cys-gly)
• Found in all mammals and is a scavenger for free radicals

Question 4

Sequence of a peptide

Answer 4

-The list of amino acids written in order from N-Terminus to C-Terminus

Question 5

Enkephalins

Answer 5

-Natural pentapeptides that bind to opiate receptors
-Enkephalins and Endorphins are classes of polypeptides synthesized by the body in response to physical stress
Ex) “Runner’s High” comes from these substances

Question 6

Polypeptide

Answer 6

Polymer of Amino Acids

-Alternating pattern of -CH(R)- alkyl groups linked by amide functional groups

Question 7

Protein

Answer 7

Polypeptides that have at least 50 or more Amino Acid Residues

Question 8

Oligopeptide

Answer 8

Chain that has ~25-50 Amino Acids

Question 9

Gramicidins

Answer 9

Small group of antibiotic polypeptides

• 6 of these are linear polypeptides of 15 Amino Acids
• All gramicidins contain D- Amino Acids

Question 10

Gramicidin S

Answer 10

Cyclic Decapeptide made up of two of the same pentapeptides joined in a head to tail linkage

• No distinct N-Terminus, either of the valine serves as the 1 position of the decapeptide
• Contains L-ornithine, a rare AA