BCH 110A Lecture 3: Amino Acids and Peptides

A series of flashcards covering key vocabulary and concepts from the BCH 110A Lecture 3 on Amino Acids and Peptides, focusing on definitions and important terms related to protein chemistry.

Amino Acids

Building blocks of proteins that serve various biological functions including catalyzing reactions as enzymes.

Peptide Bond

A covalent bond formed between the amino group of one amino acid and the carboxyl group of another, releasing water.

Zwitterion

A molecule that has both a positive and a negative charge but is overall electrically neutral, commonly found in amino acids at physiological pH.

Isoelectric Point (pI)

The pH at which an amino acid exists predominantly in its zwitterionic form, where the positive and negative charges balance out.

α-Amino Acid

An amino acid with an amino group (-NH2) attached to the carbon atom adjacent to the carboxyl group.

Chirality

The property of a molecule to exist in two non-superimposable mirror image forms, often seen in amino acids.

Ionizable Side Chains

The portions of amino acids that can donate or accept protons, affecting their charge and reactivity.

Nonpolar Amino Acids

Amino acids with side chains that are hydrophobic and do not interact favorably with water.

Aromatic Amino Acids

Amino acids that contain an aromatic ring in their side chain, which affects their properties and interactions.

Posttranslational Modification

Chemical modifications that occur to proteins after synthesis, influencing their function and activity.

Hydropathy Index

A measure of the relative polarity and hydrophobicity of amino acid side chains, guiding their behavior in proteins.

Disulfide Bond

A covalent bond formed between the sulfur atoms of two cysteine residues, contributing to protein structure stability.

Acid-Base Chemistry

Chemical reactions involving proton transfer that play a critical role in the behavior of amino acids.

Peptide

A short chain of amino acids linked by peptide bonds.

Amino Acid Classification

A categorization of amino acids based on the properties of their side chains, such as polarity and charge.

Cysteine

An amino acid containing a thiol group that can form disulfide bonds, which are important for protein structure.