Protein Structure and Function

Vocabulary flashcards covering key terms related to protein structure and function.

Protein

A macromolecule made up of amino acids that performs various functions in the cell.

Amino Acid (AA) Residue

The building blocks of proteins, with 20 naturally occurring types.

Peptide Bond

A covalent bond formed between two amino acids via a dehydration reaction.

Primary Structure

The linear sequence of amino acid residues in a protein.

Secondary Structure

Localized folding of the polypeptide chain into structures like alpha helices and beta sheets.

Tertiary Structure

The overall three-dimensional shape of a protein determined by interactions of R groups.

Quaternary Structure

The arrangement of multiple polypeptide chains in a protein.

Denaturation

The process of losing the native structure of a protein, resulting in loss of function.

Hydrophobic Effect

The tendency of non-polar groups to avoid water, influencing protein folding.

Disulfide Bond

A covalent bond formed between the sulfur atoms of two cysteine residues.

Edman Degradation

A method for sequencing amino acids in a protein from the N-terminus.

Sanger Method

A method for determining the amino acid sequence using chemical modification.

Enzymatic Hydrolysis

The use of enzymes to break peptide bonds and analyze protein structure.

Exopeptidase

An enzyme that cleaves amino acids from the ends of peptide chains.

Endopeptidase

An enzyme that cleaves peptide bonds within the protein chain.

Alpha Helix

A common secondary structure in proteins characterized by a right-handed coil.

Beta Sheet

A secondary structure in proteins formed by hydrogen bonds between segments of the chain.

Tertiary Structure Interactions

Interactions including hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges.

Globular Protein

Proteins that are compact and spherical in shape, often functional in enzymes or transport.

Fibrous Protein

Proteins that are long and strand-like, often providing structural support.

Myoglobin

A globular protein that binds oxygen in muscle tissues.

Hemoglobin

A tetrameric protein that binds oxygen in the blood and transports it to tissues.

Salt Bridge

Ionic interactions between positively and negatively charged R groups in a protein.

Alpha-Keratin

A fibrous protein that forms the outer layer of skin, hair, and nails.

Collagen

A fibrous protein that provides strength and structure in connective tissues.

Fibrin

A protein involved in blood clotting, formed from fibrinogen.

Peptide

A short chain of amino acids linked by peptide bonds.

Chromatography

A method for separating substances in a mixture based on their interactions with a stationary phase.

N-Terminus

The end of a protein or polypeptide that has a free amino group.

C-Terminus

The end of a protein or polypeptide that has a free carboxyl group.

Protein Folding

The process by which a protein assumes its functional shape.

Hydrogen Bonding

Attractive interactions between polar groups in proteins that stabilize their structure.

Hydrophobic Core

The inner region of a folded protein that is often composed of non-polar amino acid residues.

Chaperone Proteins

Proteins that assist in the proper folding of other proteins.

Disulfide Isomerase

An enzyme that helps reform disulfide bonds in proteins during folding.

Amino Acid Composition

The variety and amounts of amino acids in a protein.

Amino Acid Sequence

The order of amino acids in a protein, crucial for its function.

Peptide Bond Character

Double bond characteristics of a peptide bond that limit rotation.

Trans Configuration

A configuration in peptide bonds that minimizes steric hindrance.

Cis Configuration

A configuration that can create steric hindrance in amino acid chains.

X-Ray Crystallography

A technique used to determine the 3D structure of proteins.

Nuclear Magnetic Resonance (NMR) Spectroscopy

A technique used to determine protein structures in solution.

Mass Spectrometry

An analytical technique used to determine the mass and composition of biomolecules.

Antiparallel Beta Sheet

A type of beta sheet where adjacent chains run in opposite directions.

Parallel Beta Sheet

A type of beta sheet where adjacent chains run in the same direction.

Protein Dynamics

The study of the motion and changing states of proteins.

Oligomeric Protein

A protein composed of multiple polypeptide subunits.

Functional Conformation

The specific three-dimensional shape of a protein that is necessary for its activity.

Urea

A compound that denatures proteins by disrupting hydrogen bonds.

Renaturation

The process of a denatured protein returning to its functional state.

Christian Anfinsen

A biochemist who won the Nobel Prize for work on protein folding.

Ribonuclease (RNase)

An enzyme that catalyzes the degradation of RNA.