Protein Structure

These flashcards cover key vocabulary and concepts related to protein structure, including amino acids, different levels of protein structure, and important interactions in proteins.

Amino Acid

Monomer of proteins, consisting of a central carbon with an amino group (NH2), carboxyl group (COOH), and a unique side chain (R).

Peptide Bond

Bond between amino acids in a protein, formed via a condensation reaction and broken via hydrolysis.

Primary Structure

The sequence of amino acids in a protein, maintained by peptide bonds.

Secondary Structure

Regions of protein that form hydrogen bonds, resulting in structures like alpha-helices and beta-pleated sheets.

Tertiary Structure

The three-dimensional shape of a protein determined by interactions between R side chains.

Quaternary Structure

Structure formed by the assembly of multiple polypeptides, allowing for complex protein functionality.

Hydrophobic Interaction

A type of side chain interaction in tertiary structure where nonpolar amino acids avoid contact with water.

Disulfide Bond

A covalent bond that can form between the sulfur atoms of cysteine residues, contributing to protein stability.

Chaperone Proteins

Molecules that assist in the proper folding of proteins and prevent aggregation.

Hydrophilic

Describes amino acids or side chains that interact favorably with water.

Hydrophobic

Describes amino acids or side chains that do not interact favorably with water.

Ionic Bond

A chemical bond formed between charged side chains, contributing to protein structure.

Condensation Reaction

A chemical reaction that removes water to form a bond between molecules, such as between amino acids.

Hydrolysis Reaction

A chemical reaction that adds water to break bonds, such as breaking peptide bonds.

Side Chain (R group)

The unique part of an amino acid that determines its properties and interactions.

Electrically Charged Side Chains

Side chains that carry a full positive or negative charge, contributing to interactions with water.

Nonpolar Side Chains

Side chains that lack charged or polar groups, typically hydrophobic and less reactive.

Polar Uncharged Side Chains

Side chains with partial charges but no full charges, can form hydrogen bonds.

Amino Group

The functional group (-NH2) that is characteristic of amines, found in amino acids.

Carboxyl Group

The functional group (-COOH) that is characteristic of carboxylic acids, found in amino acids.

Hydrogen Bond

A weak interaction between a hydrogen atom and an electronegative atom, important in stabilizing secondary structures.

R Side Chain

The variable group attached to the central carbon of an amino acid, defining its characteristics.