CH3-4 P1

Macromolecule

A large molecule composed of smaller repeating subunits (monomers), typically over 1,000 daltons in mass.

Four Major Biomolecules

Proteins, carbohydrates, lipids, and nucleic acids.

Monomer

A small molecule that can bind chemically to other molecules to form a polymer.

Polymer

A large molecule made by linking together multiple monomers through chemical bonds.

Functional Group

Specific combinations of atoms that contribute certain properties (such as polarity or acidity) to molecules.

Isomer

Molecules with the same chemical formula but different structures.

Structural Isomer

Isomers that differ in how their atoms are bonded together.

Optical Isomer

Isomers that are mirror images of each other due to an asymmetrical carbon atom.

Condensation Reaction

A chemical reaction that forms a covalent bond between monomers and releases a molecule of water; used to build polymers.

Hydrolysis Reaction

A chemical reaction that breaks polymers into monomers by adding water; used in digestion.

Energy in Condensation Reactions

Requires energy input to form covalent bonds.

Energy in Hydrolysis

Releases energy by breaking bonds.

Protein

A macromolecule made of amino acid monomers linked by peptide bonds; performs many structural and functional roles.

Amino Acid

The monomer unit of proteins; contains a central carbon, amino group, carboxyl group, hydrogen, and variable R group.

Peptide Bond

The covalent bond formed between two amino acids during condensation reactions.

Three Types of Amino Acids

Charged (positive/negative), polar uncharged, and nonpolar.

Charged Amino Acids

Hydrophilic amino acids with side chains that carry a positive or negative charge.

Polar Uncharged Amino Acids

Hydrophilic amino acids with side chains that can form hydrogen bonds.

Nonpolar Amino Acids

Hydrophobic amino acids that tend to cluster in the interior of proteins.

Disulfide Bridge

A covalent bond formed between two cysteine side chains, important for protein folding.

Special Amino Acids

Glycine (smallest, fits in tight spaces), Proline (causes bends), Cysteine (forms disulfide bonds).

Primary Structure

The linear sequence of amino acids in a protein, determined by genetic code.

Secondary Structure

Regular local structures formed by hydrogen bonding in the backbone; includes α helices and β sheets.

Tertiary Structure

The overall 3D shape of a protein formed by interactions between R-groups.

Types of Tertiary Interactions

Hydrophobic aggregation, ionic bonds, hydrogen bonds, disulfide bridges, van der Waals forces.

Quaternary Structure

The structure formed when multiple polypeptide chains (subunits) come together in a single protein complex.

Examples of Quaternary Structure

Hemoglobin, composed of four subunits.

Denaturation

The loss of secondary, tertiary, or quaternary structure of a protein due to heat, pH, or other conditions.

Renaturation

The process of a protein refolding into its functional shape when favorable conditions are restored.

Protein Binding Specificity

Proteins bind to specific molecules through shape complementarity and chemical interactions involving R groups.

Importance of Protein Folding

Correct folding is essential for protein function; misfolding can cause diseases.

Functions of Proteins

Enzymes (catalysis), structural support, transport, movement, signaling, and defense.