Biological Macromolecules

Carbohydrates

Biomolecules composed of carbon, hydrogen, and oxygen with the general formula Cn(H₂O)n; also called saccharides.

Saccharide

Another term for carbohydrate, derived from the Latin word saccharum, meaning sugar.

Types of Carbohydrates

Simple carbohydrates (monosaccharides and disaccharides) and complex carbohydrates (polysaccharides).

Glucose

A monosaccharide (C₆H₁₂O₆) used as blood sugar and the main form of sugar utilized by the human body.

Galactose

A monosaccharide (C₆H₁₂O₆) found in milk and milk products.

Fructose

A monosaccharide (C₆H₁₂O₆) found in fruits and honey.

Monosaccharide Formula

Glucose, galactose, and fructose all have the chemical formula C₆H₁₂O₆, but differ in structure and properties.

Glucose

A monosaccharide (C₆H₁₂O₆) used as blood sugar and the main form of sugar utilized by the human body.

Galactose

A monosaccharide (C₆H₁₂O₆) found in milk and milk products.

Fructose

A monosaccharide (C₆H₁₂O₆) found in fruits and honey.

Monosaccharide Formula

Glucose, galactose, and fructose all have the chemical formula C₆H₁₂O₆, but differ in structure and properties.

Polysaccharide

A complex carbohydrate made of many glucose units.

Starch (Amylose)

A polysaccharide composed of 250–400 glucose units linked by α-1,4-glycosidic bonds; stores glucose in plants.

Amylopectin

A branched plant storage polysaccharide with α-1,4 and α-1,6-glycosidic bonds.

Glycogen

A highly branched polysaccharide that stores glucose in animals, mainly in the liver and muscles.

Cellulose

A polysaccharide composed of glucose linked by β-1,4-glycosidic bonds; forms plant cell walls and is indigestible to humans.

Protein

Biomolecules made of amino acids linked by peptide bonds; derived from the Greek word proteios, meaning "primary."

Polypeptide

Another term for protein; a chain of amino acids considered the building block of life.

Peptide Bond

The bond formed between amino acids, releasing one molecule of water during formation.

Amino Acids

The building blocks of proteins whose sequence determines the protein's structure and function.

Structural Proteins

Proteins that serve as the major structural components of living tissues.

Catalytic Proteins

Proteins that function as enzymes, increasing the rate of biological reactions.

Lipids

Biomolecules derived from the Greek word lipos, meaning fat; characterized by being hydrophobic (water-fearing).

Hydrophobic

The property of being insoluble in water.

Solubility of Lipids

Lipids dissolve in nonpolar solvents such as ether, acetone, and benzene.

Categories of Lipids

Wax, triglycerides, phospholipids, and steroids.

Fatty Acids

Long-chain carboxylic acids that are insoluble in water.

Saturated Fatty Acids

Fatty acids containing only single bonds in the hydrocarbon chain.

Unsaturated Fatty Acids

Fatty acids containing one or more double bonds in the hydrocarbon chain.

Triglycerides

Lipids composed of one glycerol molecule and three fatty acids.

Fat

Solid triglycerides usually obtained from animal sources such as meat, butter, milk, eggs, and cheese.

Oil

Liquid triglycerides usually obtained from plant sources.

Phospholipids

Lipids composed of glycerol, two fatty acids, and a phosphate group; have both polar and nonpolar ends, allowing them to transport molecules in the bloodstream.

Nucleic Acids

Biomolecules responsible for the storage, transfer, and expression of genetic information.

DNA (Deoxyribonucleic Acid)

The nucleic acid that stores hereditary genetic information.

RNA (Ribonucleic Acid)

The nucleic acid involved in transferring and expressing genetic information.

Nucleotide

The basic unit of nucleic acids composed of a nitrogenous base, a five-carbon sugar, and a phosphate group.

Nitrogenous Base

The nitrogen-containing component of a nucleotide.

Five-Carbon Sugar

The carbohydrate component of a nucleotide.

Phosphate Group

The component of a nucleotide that forms the backbone of nucleic acids.

DNA Nitrogenous Bases

Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).

RNA Nitrogenous Bases

Adenine (A), Guanine (G), Cytosine (C), and Uracil (U).