The Chemical Foundation of Life - Chapter 2

This set of flashcards covers key terms and concepts from Chapter 2: The Chemical Foundation of Life, focusing on the vocabulary related to atoms, molecules, chemical bonds, and the properties of water.

Atom

The smallest unit of matter that retains all of the chemical properties of an element.

Element

Unique forms of matter with specific chemical and physical properties that cannot break down into smaller substances by ordinary chemical reactions.

Molecule

Two or more atoms chemically bonded together.

Covalent Bond

Strong bond formed between two atoms when electrons are shared between them.

Ionic Bond

Chemical bond that forms between ions with opposite charges.

Hydrogen Bond

Weak bond created by the attraction between slightly positive hydrogen atoms in one molecule and slightly negative atoms in another.

Isotope

Different forms of an element that have the same number of protons but a different number of neutrons.

Proton

Positively charged particle that resides in the atom's nucleus.

Neutron

Uncharged particle that resides in an atom's nucleus.

Electron

Negatively charged subatomic particle that resides outside of the nucleus in the electron orbital.

pH Scale

Scale from 0 to 14 that measures the concentration of hydrogen ions in a solution.

Acid

Substance that increases the concentration of hydrogen ions in a solution.

Base

Substance that decreases the hydrogen ion concentration in a solution.

Bufffer

Substance that resists changes in pH by absorbing or releasing hydrogen or hydroxide ions.

Hydrophobic

Describes molecules that do not interact well with water.

Hydrophilic

Describes ions or polar molecules that interact well with water.

Hydration Shell

Sphere of water molecules that forms around particles when they dissolve in water.

Surface Tension

The capacity of a substance to withstand rupturing when placed under tension; due to cohesive forces among molecules.

Cohesion

Intermolecular forces between water molecules that keep them together due to hydrogen bonding.

Adhesion

Attraction between water molecules and other molecules.

Dissociation

Release of an ion from a molecule, such as when water dissociates into H+ and OH-.

Carbon Backbone

The central chain or ring of carbon atoms in an organic molecule.

Functional Groups

Groups of atoms within molecules that confer specific chemical properties.

Hydrocarbon

Organic molecule consisting entirely of carbon and hydrogen.

Saturated Fat

Fatty acid with no double bonds in its carbon chain, solid at room temperature.

Unsaturated Fat

Fatty acid with one or more double bonds in its carbon chain, liquid at room temperature.

Enantiomers

Molecules that are mirror images of each other.