Amino Acids

Monomers

• amino acids are the backbone of peptides and proteins

Macromolecules

• proteins and peptides are built out of amino acids

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Amino Acids

all amino acids contain:

• a central carbon atom (C)
• an amino group (NH₂)
• a carboxylic acid group (COOH)
• a side chain (R)

Amino Acid - General Structure

HH O
|| ‖
N - C - C
|| |
HR O-H

Amino Acids - Chemical Formula

 R-CH(NH₂)COOH

the properties of amino acids are determined by the functional substituents linked on the side chains (side chains also referred to as R groups)

there are 20 standard side chains/R groups/residues found in nature

Peptide Bond Formation

2 amino acids bond together via dehydration synthesis/condensation reaction
H H O H H O H H O H O
| | ‖ || ‖ | | ‖ | ‖
N - C - C + N - C - C = N - C - C - N - C - C + H2O
| | | | | | | | | | |
H R1 O-H H R2 O-H H R1 H R2 O-H

Amino Acid - Types

• Aliphatic Amino Acids with Hydrophobic Side Chain
• Aromatic Amino Acids with Hydrophobic Side Chain
• Amino Acids with Neutral Side Chain
• Amino Acids with Positively Charged Side Chain
• Amino Acids with Negatively Charged Side Chain
• Unique Amino Acids