AP Biology | Unit 1 Review

Ionic Bond

A type of chemical bond that involves the transfer of electrons from one atom to another, resulting in the formation of charged ions.

Covalent Bond

A chemical bond formed when two atoms share one or more pairs of electrons.

Hydrogen Bond

A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.

Polar Molecule

A molecule that has a partial positive charge on one side and a partial negative charge on the other due to uneven distribution of electrons.

Nonpolar Molecule

A molecule that does not have distinct positive or negative regions, and the electrons are shared evenly.

Hydration Shell

The structure formed when water molecules surround and interact with solute particles.

pH scale

A logarithmic scale used to specify the acidity or basicity of an aqueous solution.

Acid

A substance that increases the hydrogen ion concentration in a solution.

Base

A substance that decreases the hydrogen ion concentration in a solution.

Dehydration Reaction

A chemical reaction that involves the loss of a water molecule from the reacting compound.

Hydrolysis Reaction

A reaction that breaks down compounds by the addition of water.

Aqueous Solution

A solution in which water is the solvent.

Saccharide

The basic unit of carbohydrates; can be a simple sugar or a larger, complex carbohydrate.

Monomer

A small molecule that can join together with other similar molecules to form a polymer.

Polymer

A large molecule composed of repeating structural units (monomers) bonded together.

Enzyme

A biological catalyst that accelerates a chemical reaction by lowering the activation energy.

Glycoprotein

A molecule that consists of a carbohydrate attached to a protein, playing key roles in cell-cell recognition and signaling.

Functional Group

A specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule.

Isomer

Compounds that have the same molecular formula but different structures and properties.

Macromolecule

A large molecule composed of thousands of atoms, such as proteins, nucleic acids, and carbohydrates.

Carbohydrate

Organic molecules made up of carbon, hydrogen, and oxygen, typically with a hydrogen-oxygen ratio of 2:1.

Lipid

A diverse group of hydrophobic organic molecules including fats, oils, and phospholipids, which are essential for building cellular membranes.

Protein

A macromolecule composed of one or more chains of amino acids, responsible for various functions within the cell.

Nucleic Acid

Biopolymers, such as DNA and RNA, composed of nucleotide monomers that store and transmit genetic information.

Carbon Cycle

The series of processes by which carbon compounds are interconverted in the environment, central to life on Earth.

Saturated Fatty Acid

A type of fat that contains no double bonds between carbon atoms, fully saturated with hydrogen.

Unsaturated Fatty Acid

A fatty acid that contains one or more double bonds, resulting in fewer hydrogen atoms.

Amino Acid

Organic compounds that combine to form proteins and contain an amino group, carboxyl group, and a distinctive side chain.

Peptide Bond

A covalent bond formed between two amino acids, resulting in a protein.

Valence Electron

An electron that is found in the outermost shell of an atom and can participate in forming chemical bonds.

Activation Energy

The minimum amount of energy required to initiate a chemical reaction.

Substrate

The reactant on which an enzyme works.

Allosteric Site

A site on an enzyme where a molecule can bind, regulating the enzyme's activity.

Hydrophobic Interaction

The tendency of nonpolar substances to aggregate in aqueous solution to minimize exposure to water.

Octet Rule

The principle that atoms are especially stable when they have eight electrons in their valence shell.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process by which ribosomes synthesize proteins using mRNA.