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Question 1

What functional group is formed when a peptide bond is formed?

Answer 1

an amide group.

Question 2

List three things that are not important to chromatography?

Answer 2

1. not thickness of the paper
2. not the concentration of solute or solvent.
   The bonding between the paper and the mobile phase is important.

Question 3

In determining which reactant loses the –OH group, which of the following isotopic substitutions would be most useful?

Answer 3

Replace the hydroxyl oxygen of ethanol with O-18. Labeling a group which does not exchange with other groups present prior to reaction and will therefore give information about the true identity of the groups, which are exchanged during the reaction.

Question 4

Define nucleophile

Answer 4

nucleophile is a chemical species that donates an electron pair to form a chemical bond in relation to a reaction. All molecules or ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are by definition Lewis bases. Commonly C, H, O, N as an anion or lone pair

Question 5

Define electrophile

Answer 5

electrophile is an electron pair acceptor. Electrophiles are positively charged or neutral species having vacant orbitals that are attracted to an electron rich centre. It participates in a chemical reaction by accepting an electron pair in order to bond to a nucleophile.

Question 6

2 step reaction, favored by polar protic solvents, 
3˚>2˚>1˚>methyl, 
rate=k[RL]
racemic products, 
strong nucleophile not needed

Answer 6

Sn1

Question 7

1 step reaction

Answer 7

Sn2

Question 8

What type of chromatography is his tagged and nickel purification?

Answer 8

Affinity chromatography.

Question 9

Describe an epimer

Answer 9

Epimer: each of two isomers with different configurations of atoms around one of several asymmetric carbon atoms present. Alpha & Beta distinguishes between molecules with multiple chiral centers, but differ only in the configuration of the site known as the anomeric carbon atom.

Question 10

Describe an anomeric carbon

Answer 10

The anomeric carbon is a stereocenter. An important feature is the direction of the OH group attached to the anomeric carbon. Depending on the direction of the OH group, the anomeric carbon is either α or β. α: equatorial DOWN or axial DOWN. β: equatorial UP or axial UP.

Question 11

Describe an enantiomer

Answer 11

each of a pair of molecules that are mirror images of each other.