Biology Chapter 2 - The Chemistry of Life

Atom

Basic unit of matter

Element

Pure substances that consist entirely of one type of atom

Isotope

Atoms of the same elements that differ in the number of neutrons they contain

Compound

A substance formed by the chemical combination of two or more elements

Ionic bond

When one or more electrons are transferred from one atom to another

Ions

Positively or negatively charged atoms

Covalent bond

When one or more electrons are shared

Cohesion

Attraction between molecules of the same substance

Adhesion

Attraction between molecules of different substances

Capillary Action

Ability of a liquid to flow in narrow spaces without the assistance of external forces like gravity

Heat Capacity

The amount of energy needed to raise a substance's temperature by making its molecules move faster

Monomers

Smaller units used to make polymers

Polymers

Larger units made up of monomers

Polymerization

A chemical process that combines several monomers to form a polymer

Carbohydrate

Made up of C, H, and O
Store and release energy

Lipids

Mostly C and H
Store energy, form biological membranes

Nucleic Acids

Made of nucleotides
Store and transmit genetic information

Protein

Made of amino acids
Repair muscle tissue, control reactions, regulate cell processes

Reactants

Elements or compounds that engage in a chemical reaction

Products

Elements or compounds produced by a chemical reaction

Activation energy

The energy required to start a reaction

Enzymes

Biological catalysts that speed up chemical reactions by lowering the activation energy

Lock-and-key model

The active site of an enzyme is shaped to hold specific substrates

Induced-fit model

The active site and substrate don't fit perfectly; instead, they both can change their shape to connect

Solute

Material that gets dissolved- smaller quantities

Solvent

Material that does the dissolving - larger quantities