Chapter 5 - Macromolecules

Macromolecules

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

Polymer

A long molecule consisting of many similar building blocks called monomers.

Monomer

The repeating units that serve as building blocks for polymers.

Dehydration reaction

A reaction in which two molecules are bonded together through the loss of a water molecule.

Hydrolysis

A reaction that disassembles polymers into monomers through the addition of water.

Carbohydrates

Macromolecules that include sugars and their polymers, serving as major energy sources for cells.

Monosaccharides

The simplest carbohydrates, or simple sugars, that serve as major fuel for cells.

Disaccharides

Carbohydrates formed by joining two monosaccharides through a covalent bond.

Polysaccharides

Carbohydrates that are polymers of many monosaccharides.

Glycosidic linkage

The covalent bond formed between monosaccharides during the formation of disaccharides and polysaccharides.

Starch

A storage polysaccharide of plants, consisting of glucose monomers.

Glycogen

A storage polysaccharide in animals, similar to amylopectin but more highly branched.

Cellulose

A structural polysaccharide that is a major component of the tough wall of plant cells.

Chitin

Another structural polysaccharide found in the exoskeleton of arthropods and cell walls of fungi.

Proteins

Macromolecules that account for more than 50% of the dry mass of most cells, with various functions including catalysis and transport.

Amino acids

Organic molecules that are the building blocks of proteins; there are 20 different amino acids.

Peptide bond

The bond formed between amino acids through a dehydration reaction.

Primary structure

The unique sequence of amino acids in a protein.

Secondary structure

Coils and folds in a polypeptide chain, typically forming alpha helices and beta pleated sheets.

Tertiary structure

The overall shape of a polypeptide resulting from interactions among various side chains.

Quaternary structure

The structure formed when two or more polypeptide chains assemble into a single macromolecule.

Nucleic acids

Polymers called polynucleotides that include DNA and RNA, responsible for the storage and transfer of genetic information.

Nucleotide

The monomer of nucleic acids, consisting of a nitrogenous base, a pentose sugar, and one or more phosphate groups.

Complementary base pairing

The specific pairing of nitrogenous bases in DNA (A with T, G with C) and in RNA (A with U, G with C).

Lipids

A diverse group of large biological molecules that are hydrophobic and do not form polymers.

Fatty acids

Carboxyl acids with long hydrocarbon chains; they can be saturated or unsaturated.

Phospholipids

Lipids consisting of two fatty acids and a phosphate group attached to glycerol, crucial for cell membrane structure.