Basic Structure of an Amino Acid
Each amino acid has 5 main parts:
Central Carbon Atom (C)
This is the “center” of the molecule. Everything else is attached to this carbon.
Amino Group (–NH₂)
This part has nitrogen and hydrogen.
It acts like a base and is the reason it’s called an “amino” acid.
Carboxyl Group (–COOH)
This part has carbon, oxygen, and hydrogen.
It acts like an acid — that’s why it’s called an “acid.”
Hydrogen Atom (H)
Just a single hydrogen atom connected to the central carbon.
Side Chain (R group)
This is the unique part.
It can be small, big, simple, or complex.
The R group is what makes each amino acid different.
Visual (Described in Words)
Imagine it like a small cross:
H
|
NH2—C—COOH
|
R
• In the center is the carbon (C).
• To the left is the amino group (NH₂).
• To the right is the carboxyl group (COOH).
• Above is a hydrogen atom (H).
• Below is the R group, which is different for every amino acid.
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Example:
• In glycine, the R group is just a hydrogen — very simple.
• In tyrosine, the R group is much bigger — a ring-shaped group with oxygen.
My favourite part/note/summary- central carbon atom is in the middle, followed by amino group, this group has nitrogen and hydrogen, this is how the word amino came. And then it is Carboxyl group which includes hydrogen, oxygen and carbon. And then a hydrogen atom. And the last one side chain, this is what makes each amino acid different, it can be big, small, simple or even complex.
