SL - Imine

Question 1

What are imines formed from?

Answer 1

Aldehyde + Primary Amine

Ketone + Primary Amine

Question 2

What is imine formation?

Answer 2

Imine formation is an acid-catalysed and reversible dehydration

Question 3

What 3 steps are involved in the hemiaminal formation?

Answer 3

1. C=O group on oxygen gets protonated
2. Nucleophilic attack by lone pair on nitrogen atom
3. Deprotonation on nitrogen atom

Question 4

What are the 3 main steps of Imine formation?

Answer 4

1. Protonation of the hydroxyl group to form water
2. Loss of H2O leaving group and formation of double bond with nitrogen
3. Loss of a proton gives the imine product and regenerates the catalyst

Question 5

What happens when an Aldehyde/Ketone react with a secondary amine?

Answer 5

In the final step, the iminium ion has no N-H bond, so deprotonation takes place from the adjacent atom instead- Enamine formed

Question 6

How does the GFP fluorphore work?

Answer 6

1. A protein called aequorin releases blue light upon calcium binding
2. The blue light is absorbed by the GFP which then gives off green light

Question 7

What 3 amino acids are present in the fluorphore?

Answer 7

Ser65, Tyr66, Gly67

Question 8

What are the Ka and pKa values for strong acids?

Answer 8

High Ka values
Low pKa values

Question 9

What is the strength of a Brønsted base related to?

Answer 9

The strength of its conjugate acid

If the conjugate acid is weak, the base is strong