Chapter 3: Protein Structure and Function

Flashcards covering key terms and concepts from Chapter 3 of Biological Science relating to protein structure and function.

Macromolecules

Large molecules composed of thousands of atoms, including proteins, nucleic acids, carbohydrates, and lipids.

Amino Acids

Building blocks of proteins; there are 20 different types, each with a unique side chain.

Peptide Bond

Covalent bond formed between the carboxyl group of one amino acid and the amino group of another, linking amino acids in a protein.

Primary Structure

The unique sequence of amino acids in a polypeptide chain.

Secondary Structure

Local folding of the polypeptide chain into structures such as alpha-helices and beta-pleated sheets, stabilized by hydrogen bonds.

Tertiary Structure

The overall three-dimensional shape of a polypeptide, resulting from interactions between R-groups.

Quaternary Structure

The structure formed by the assembly of two or more polypeptide chains.

R-group

The side chain of an amino acid that determines its properties and classification.

Denaturation

The process in which proteins lose their native structure, resulting in loss of function.

Enzyme

A protein that acts as a catalyst to increase the rate of a chemical reaction.

Prions

Infectious agents composed of protein that can induce other proteins to misfold, leading to disease.

Ionizable Groups

Functional groups in amino acids that can gain or lose protons, affecting charge and solubility.

Macromolecules

Large molecules composed of thousands of atoms, including proteins, nucleic acids, carbohydrates, and lipids.

Amino Acids

Building blocks of proteins; there are 20 different types, each with a unique side chain.

Peptide Bond

Covalent bond formed between the carboxyl group of one amino acid and the amino group of another, linking amino acids in a protein.

Primary Structure

The unique sequence of amino acids in a polypeptide chain.

Secondary Structure

Local folding of the polypeptide chain into structures such as alpha-helices and beta-pleated sheets, stabilized by hydrogen bonds.

Tertiary Structure

The overall three-dimensional shape of a polypeptide, resulting from interactions between R-groups.

Quaternary Structure

The structure formed by the assembly of two or more polypeptide chains.

R-group

The side chain of an amino acid that determines its properties and classification.

Denaturation

The process in which proteins lose their native structure, resulting in loss of function.

Enzyme

A protein that acts as a catalyst to increase the rate of a chemical reaction.

Prions

Infectious agents composed of protein that can induce other proteins to misfold, leading to disease.

Ionizable Groups

Functional groups in amino acids that can gain or lose protons, affecting charge and solubility.

What determines an amino acid's classification?

The R-group (side chain) determines if an amino acid is nonpolar, polar, acidic (negatively charged), or basic (positively charged.

What major types of interactions stabilize a protein's tertiary and quaternary structures?

Hydrophobic interactions, hydrogen bonds, ionic bonds, and disulfide bridges.

What are some diverse functions of proteins in living organisms?

Proteins function in catalysis (enzymes), structural support, transport, cellular communication, movement, and defense.

What are chaperone proteins?

Proteins that assist in the proper folding of other proteins, especially under stress conditions, preventing misfolding and aggregation.