Biology Exam Review Flashcards

A collection of vocabulary terms with definitions to assist students in reviewing key concepts in biology.

Element

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

Trace Elements

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

Atom

The smallest unit of an element that has its characteristic properties.

Isotope

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

Hydrogen Bond

An attractive force formed between water molecules due to their polarity.

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 through narrow spaces due to cohesion and adhesion.

pH

A measure of how acidic or basic a solution is.

Acid

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

Base

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

Macromolecule

A large complex molecule, such as carbohydrates, proteins, lipids, and nucleic acids.

Monomer

The building blocks of macromolecules, such as glucose for carbohydrates or amino acids for proteins.

Polysaccharide

A carbohydrate made up of many monosaccharides, such as starch or cellulose.

Glycosidic Linkage

The bond formed between two monosaccharides during a condensation reaction.

Condensation Reaction

A chemical reaction where two molecules combine to form a larger molecule, producing water as a byproduct.

Hydrolysis

The chemical breakdown of a compound due to reaction with water.

Protein

A macromolecule composed of amino acids that perform various functions in organisms.

Enzyme

A biological catalyst that speeds up chemical reactions by lowering the activation energy.

Active Site

The region on an enzyme where substrates bind and undergo a chemical reaction.

Photosynthesis

The process by which plants, algae, and some bacteria convert light energy into chemical energy.

Cellular Respiration

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Natural Selection

The process by which individuals with favorable traits are more likely to survive and reproduce.

Mutation

A change in the DNA sequence that may affect genetic information.

Ecosystem

A community of living organisms interacting with their environment.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance.

Symbiosis

A close relationship between two or more species that may benefit one or both of the species involved.

Adaptation

A trait that helps an organism survive and reproduce in its environment.