Ch. 26 - Amino Acids, Peptides, and ProteinsSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Amino Acid Chart

See all sections
Sections
Proteins and Amino Acids
L and D Amino Acids
Polar Amino Acids
Amino Acid Chart
Acid-Base Properties of Amino Acids
Isoelectric Point
Additional Practice
Amino Acid Nomenclature

Are you ready to learn the 20 amino acids?! Let's get started. 

Concept #1: Nonpolar Amino Acids

There are 6 amino acids in the polar side-chain category. Let's learn them!

Concept #2: Polar Amino Acids

5 more! In the following video we will learn the 2 acidic and 3 basic side chains for amino acids. 

Concept #3: Charged Amino Acids

There are 9 essential amino acids. Let's dive deeper into their meaning.

Concept #4: Essential Amino Acids

Major props if you made it this far. Below we will use the tips and tricks learned above to fill in a blank chart and do some practice problems. Let's do this. 

Example #1: Blank Amino Acid Worksheet

Practice: Non-Polar Sidechains - Fill in the missing sidechains on the following target tripeptide.

Practice: Non-Polar Sidechains - Fill in the missing sidechains on the following target tripeptide.

Practice: Non-Polar Sidechains - Provide the complete structure of the tripeptide P-F-W

Practice: Polar Sidechains - Provide the Fischer Projection of Glutamine (Q)

Practice: Polar Sidechains - Provide the complete structure of the dipeptide Asn-Cys

Practice: Polar Sidechains - Fill in the missing sidechains on the following target oligopeptide.

Note: While the structure of Asparagine is correctly drawn at position #5 in the above video. The abbreviation "N" actually belongs to Asparagine, not Arginine.

Practice: Acidic/Basic Sidechains - Provide the Fischer Projection of Amino Acid (H)

Practice: Acidic/Basic Sidechains - Fill in the missing sidechains on the following target oligopeptide.

Practice: Acidic/Basic Sidechains - Provide the complete structure of the oligopeptide V-I-D-Y. Based on your knowledge of hydrophobicity, which side of the peptide is more likely bury itself within the protein?

Additional Problems
Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids. (a) Alanine (R = methyl)   
Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids. (b) Valine (R = isopropyl)  
Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids.(c) Leucine (R = isobutyl)   
Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids. (f) Cysteine (R = XCH2 , where X is the functional group that characterizes thiols)  
Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids. (g) Aspartic acid (R = XCH2 , where X is the functional group that characterizes carboxylic acids)  
Combine these amino acids into a tripeptide. Add or remove atoms and bonds as needed. 
What amino acid is depicted in the figure below? (Carbon atoms are not labeled) a. Alanine b. Valine c. Leucine d. Isoleucine e. Asparagine
Which of the following amino acids contains a nonpolar R group? a. Lysine b. Isoleucine c. Aspartate d. Glutamate e. Arginine
Which of the following a-amino acids possesses two hydrogen atoms adjacent to the carboxylic acid?A. PhenylalanineB. TryptophanC. LysineD. GlycineE. Serine
Below is a tripeptide. Answer parts a, b, and c regarding this tripeptide. a) Which amino acid is the N-terminal amino acid?                       • threonine                       • valine                       • methionine                       • cysteineb) What is the name of this tripeptide, using the three-letter amino acid abbreviations? Capitalize the first letter of each abbreviation.