How do you tell the difference between different amino acid structures?

Question

I have to memorize these structures for a class and when I google them, I get different structures each time. Some are linear, some have shapes in them and stuff like that and I know they must mean the same thing, but how can I determine the identity of a structure that is using shapes by using the linear formula or vice versa? I don't know which form I am going to be given.

Answer 1

Depending on how strict your teacher is, you may have to memorize all 20 amino acids.

The structural and chemical formulas for the 20 are completely interchangeable, so you are just going to have to memorize all of them and recognize when they are in each form.

The memorization of made very easy by the fact that all amino acids contain the same basic structure:
NH2
|
CH----X
|
C=O
|
OH

Where X is the function group which classifies the amino acid. If you can memorize 20 functional groups you can make you job much easier than trying to remember 20 complete structures.

Answer 2

Each amino acid has a N-terminus and a C-terminus. The difference between the linear and branched structures is simply for depiciton. Chemically they are the same. The branched ones just more accurately depict the positions of indiividual atoms in the amino acid due to electron repulsion.

Answer 3

NH2
|
CH----X
|
C=O
|
OH
While learning you should classify the 20 Amino acids found in Higher Living organisms into different groups ,like straight chain/branched chain Aliphatic,Aromatic/alicyclic,Sulphur containing etc -then it is easy to remember.