Unit 1: Chemistry of Life - AP BIO

Elements

Elements

Substances that cannot be broken down into simpler substances by chemical means.

Trace elements

Elements required by an organism in very small quantities.

Protons

Positively charged particles found in the nucleus of an atom.

Neutrons

Uncharged particles found in the nucleus of an atom.

Electrons

Negatively charged particles found outside the nucleus of an atom.

Isotopes

Atoms with the same number of protons but different number of neutrons in the nucleus.

Compounds

Consist of two or more elements held together by chemical bonds.

Ionic bond

Formed when one or more electrons are transferred from one atom to another.

Covalent bond

Formed when electrons are shared between atoms.

Hydrogen bond

Weak chemical bond formed between a hydrogen atom and another atom.

Cohesion

The tendency of water molecules to stick together.

Adhesion

The tendency of water molecules to stick to other substances.

Capillary action

The ability of water to rise up in narrow tubes against the force of gravity.

Surface tension

The cohesive forces between water molecules at the surface, creating a "skin" or tension.

Acids

Solutions that contain a lot of hydrogen ions (H+).

Bases

Solutions that release a lot of hydroxide ions (OH–).

pH scale

A scale used to measure the acidity or alkalinity of a solution.

Organic molecules

Molecules that contain carbon atoms.

Inorganic compounds

Molecules that do not contain carbon atoms.

Polymers

Chains of building blocks in macromolecules.

Monomers

Individual building blocks of a polymer.

Dehydration synthesis

A reaction where a water molecule is lost and a larger compound is formed.

Hydrolysis

A reaction where polymers are broken down into monomers with the addition of water.

Carbohydrates

Organic compounds that contain carbon, hydrogen, and oxygen in a ratio of approximately 1:2:1.

Monosaccharides

Simple sugars that serve as an energy source for cells.

Disaccharides

Two monosaccharides joined together by a glycosidic linkage.

Polysaccharides

Chains of many repeated units of monosaccharides.

Proteins

Important for structure, function, and regulation of tissues and organs.

Amino acids

Building blocks of proteins, containing carbon, hydrogen, oxygen, and nitrogen atoms.

Polypeptides

Chains of amino acids joined by peptide bonds.

Lipids

Organic compounds that consist of carbon, hydrogen, and oxygen atoms.

Triglycerides

Lipids made of a glycerol molecule and three fatty acid chains.

Phospholipids

Lipids with two fatty acid tails and a negatively charged phosphate head.

Cholesterol

A four-ringed molecule found in membranes, important for membrane fluidity and hormone synthesis.

Nucleic acids

Molecules made up of nucleotides, containing carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms.

DNA

Contains the hereditary "blueprints" of all life.

RNA

Essential for protein synthesis.