AP Biology Ultimate Guide (copy)

Element

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

Trace Elements

Elements required by organisms in very small quantities, such as iron (Fe), iodine (I), and copper (Cu).

Atom

The basic unit of life, made up of subatomic particles: protons, neutrons, and electrons.

Proton

A positively charged particle found in the nucleus of an atom.

Neutron

An uncharged particle found in the nucleus of an atom.

Electron

A negatively charged particle that orbits the nucleus of an atom.

Isotope

Atoms with the same number of protons but different numbers of neutrons.

Compound

A substance made up of two or more elements held together by chemical bonds.

Ionic Bond

A bond formed when one or more electrons are transferred from one atom to another.

Covalent Bond

A bond formed when two atoms share electrons.

Polar Covalent Bond

A type of covalent bond where electrons are shared unequally between the atoms.

Non-Polar Covalent Bond

A type of covalent bond where electrons are shared equally between the atoms.

Hydrogen Bond

A weak chemical bond that forms between a hydrogen atom covalently bonded to one atom and another atom.

Cohesion

The tendency of water molecules to stick together due to hydrogen bonding.

Adhesion

The tendency of water molecules to stick to other substances.

Capillary Action

The ability of water to rise up against gravity in narrow tubes or spaces due to cohesion and adhesion.

pH Scale

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

Acid

A substance that increases the concentration of hydrogen ions (H+) in a solution.

Base

A substance that increases the concentration of hydroxide ions (OH-) in a solution.

Organic Molecules

Molecules that contain carbon and are central to life processes.

Monomer

The individual building blocks of a polymer.

Polymer

Chains of monomers that form larger macromolecules.

Hydrolysis

The process of breaking down polymers into monomers by adding water.

Dehydration Synthesis

The process of combining monomers to form polymers, releasing water.

Carbohydrates

Organic compounds made of carbon, hydrogen, and oxygen, typically in a 1:2:1 ratio.

Monosaccharide

The simplest form of carbohydrates, consisting of single sugar molecules.

Disaccharide

A carbohydrate made up of two monosaccharides joined together.

Polysaccharide

Carbohydrates that are made up of more than two monosaccharides.

Protein

Macromolecules made of amino acids, essential for structure, function, and regulation of tissues.

Amino Acid

Building blocks of proteins that contain an amino group, carboxyl group, hydrogen, and a side chain (R-group).

Peptide Bond

The bond formed between two amino acids during protein synthesis.

Lipids

Organic compounds made mostly of carbon and hydrogen, including fats, oils, and steroids.

Phospholipids

Lipids with hydrophilic heads and hydrophobic tails that make up cell membranes.

Nucleic Acids

Biomolecules (DNA and RNA) that store and transmit genetic information.

DNA

Deoxyribonucleic acid, a molecule that carries genetic information.

RNA

Ribonucleic acid, involved in protein synthesis and gene expression.

Mitosis

The process of cell division that results in two identical daughter cells.

Meiosis

A special type of cell division that reduces the chromosome number by half, producing gametes.

Natural Selection

The process through which organisms better adapted to their environment tend to survive and produce more offspring.