6.2.2 Amino Acids, Amides and Chirality: Module 6: Organic Chemistry & Analysis Chemistry OCR A A Level

What are the two functional groups of amino acids?

NH2 and COOH (amine and carboxylic acid).

Are α-amino acids chiral? Why?

Yes, one carbon has 4 different substituents.

Except glycine, where R = H.

Define a zwitterion.

Ions which have both a permanent positive and negative charge, but are neutral overall.

What property must a carbon atom have for the molecule to display optical isomerism about that carbon atom?

4 different substituents attached to one carbon atom.

What are the similarities and differences between two optical isomers?

Same atoms and bonds, but they are non-superimposable mirror images of one another. NOT IDENTICAL in chemical properties necessarily.

Differ in the way they rotate plane polarised light - rotate plane of polarisation by the same angle but in different directions.

What word is used to describe optically active molecules?

Chiral