Biochemistry Structure and Names of Amino Acids

Chapter 3: Amino Acids, Peptides, Proteins

What are proteins?

The main agents of biological function

What are amino acids?

The building blocks of proteins

What does a typical amino acid contain?

• A central carbon (a-carbon) connected to:

  • Amino group (-NH2)

  • Carboxyl group (-COOH)

  • Hydrogen atom (-H)

  • Unique side chain (R-group)

How many substituents does the a-carbon have? And what structure is it?

• 4

• Tetrahedral

All except which amino acid have an acidic carboxylic group, a basic amino group, and an a-hydrogen connected to the a-carbon?

Proline

These are…?

Enantiomers

Which R groups are hydrophobic?

Nonpolar or Aliphatic R groups

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Glycine

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Alanine

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Proline

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Valine

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Leucine

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Isoleucine

What structure is this? And what group does it fall under?

• Nonpolar, Aliphatic

• Methionine

What are the 5 groups of the common amino acids depending on their R-groups?

• Nonpolar, aliphatic

• Aromatic

• Polar, uncharged

• Positively charged

• Negatively charged

Which amino acid side chains can absorb UV light at 270-280nm?

Aromatic

What structure is this? And what group does it fall under?

• Phenylalanine

• Aromatic

What structure is this? And what group does it fall under?

• Tyrosine

• Aromatic

What structure is this? And what group does it fall under?

• Tryptophan

• Aromatic

Which amino acid side chains can from hydrogen bonds?

Polar, uncharged R-groups

Which R-group can from disulfide bonds?

Cysteine

What structure is this? And what group does it fall under?

• Serine

• Polar, Uncharged

What structure is this? And what group does it fall under?

• Threonine

• Polar, Uncharged

What structure is this? And what group does it fall under?

• Cysteine

• Polar, Uncharged

What structure is this? And what group does it fall under?

• Cystine

• Polar, Uncharged

What structure is this? And what group does it fall under?

• Asparagine

• Polar, Uncharged

What structure is this? And what group does it fall under?

• Glutamine

• Polar, Uncharged

What structure is this? And what group does it fall under?

• Lysine

• Positively charged (basic)

What structure is this? And what group does it fall under?

• Arginine

• Positively charged (basic)

What structure is this? And what group does it fall under?

• Histidine

• Positively charged (basic)

What are the roles of the acid and base in positively/negatively charged R-groups

Acid = proton donor

Base = proton acceptor

What structure is this? And what group does it fall under?

• Aspartate

• Negatively Charged

What structure is this? And what group does it fall under?

• Glutamate

• Negatively Charged

What structure is this?

Phosphoserine

What structure is this?

Phosphotheronine

What structure is this?

Phosphotyrosine

What structure is this?

a-N-Methylarginine

What structure is this?

6-N-Acetyllysine

What structure is this?

Glutamate methyl ester

What structure is this?

Adenylyltyrosine