Chapter 5: Organic Molecules

Carbohydrates

Sugars and polymers of sugars.

Lipids

Fats, phospholipids, and steroids; hydrophobic molecules.

Proteins

Polymers of amino acids.

Nucleic Acids

DNA and RNA.

Dehydration Reaction

Builds polymers by linking monomers through the removal of a water molecule.

Hydrolysis

Breaks down polymers into monomers by adding a water molecule.

Monosaccharides

Simple sugars with the basic formula (CH₂O)n.

Disaccharides

Formed by a dehydration reaction between two monosaccharides; bonded by glycosidic linkage.

Polysaccharides

Large polymers of sugars with storage or structural functions.

Glycogen

Storage polysaccharide in animals, found in liver and muscle cells.

Cellulose

Structural polysaccharide in plants, major component of cell walls; humans cannot digest it.

Starch

Storage polysaccharide in plants, stored in chloroplasts; example includes amylose.

Chitin

Structural polysaccharide found in fungal cell walls and arthropod exoskeletons.

Saturated fats

Fats with no double bonds between carbon atoms; solid at room temperature.

Unsaturated fats

Fats with one or more double bonds, liquid at room temperature.

Hydrogenation

Process of adding hydrogen to unsaturated fats to make them saturated, creating trans fats.

Phospholipids

Molecules made of glycerol, 2 fatty acids, and a phosphate group; form the phospholipid bilayer.

Steroids

Lipids with a structure of four fused carbon rings; includes cholesterol and hormones.

Amino Acids

Building blocks of proteins, containing an amino group, carboxyl group, and R-group.

Peptide Bonds

Covalent bonds linking amino acids through dehydration reactions.

Primary Structure

The sequence of amino acids in a polypeptide chain.

Secondary Structure

Structures formed by hydrogen bonds creating alpha-helices and beta-sheets.

Tertiary Structure

The 3-dimensional shape formed by interactions between R-groups.

Quaternary Structure

Structure formed by the combination of multiple polypeptide chains.

What is a dehydration reaction in the context of biological macromolecules?

A process that builds polymers by linking monomers through the removal of a water molecule.

What distinguishes saturated fats from unsaturated fats?

Saturated fats have no double bonds between carbon atoms, while unsaturated fats have one or more double bonds.

What is the primary structure of a protein?

The sequence of amino acids that determines the final shape of the protein.

What are the functions of carbohydrates in biological systems?

Serve as fuel for cells and as raw materials for building molecules.

What is the significance of phospholipids in cell biology?

They form the phospholipid bilayer in cell membranes, with hydrophilic heads and hydrophobic tails.