Chemical Composition of Proteins
Basic Building Blocks
Proteins are complex molecules made up of smaller units called amino acids. Let's break down their chemical composition:
- All amino acids contain:
- An amino group (-NH₂)
- A carboxyl group (-COOH)
- A central carbon atom (α-carbon)
- A side chain (R group)
The R group is what makes each amino acid unique and gives it specific properties.
Chemical Elements
The main elements found in proteins are:
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
- Nitrogen (N)
- Sometimes Sulfur (S)
Remember the acronym CHONS to recall the elements in proteins - Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur!
FORMULA: COOHNH2
Peptide Bonds
Amino acids join together through peptide bonds to form proteins. Here's how it works:
- The carboxyl group (-COOH) of one amino acid reacts with the amino group (-NH₂) of another
- A water molecule is released (dehydration synthesis)
- The resulting bond is called a peptide bond
