Biological Chemistry

Flashcards covering key vocabulary and concepts from the Biological Chemistry lecture notes.

Element

A substance that cannot be broken down to other substances by chemical reactions.

Compound

A substance consisting of two or more elements in a fixed ratio.

Trace elements

Elements that an organism requires but only in minute quantities.

Atom

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

Neutron

Subatomic particle with no electrical charge.

Proton

Subatomic particle with a positive charge.

Electron

Subatomic particle with a negative charge.

Energy

The capacity to cause change.

Potential Energy

Energy that matter possesses because of its location or structure.

Energy Level (Electron Shell)

An electron's state of potential energy.

Valence Electrons

Electrons in the outermost shell.

Valence Shell

Outermost electron shell.

Chemically Inert

Atoms with a full valence shell; chemically unreactive.

Covalent Bond

The sharing of a pair of valence electrons by two atoms.

Molecule

Two or more atoms held together by covalent bonds.

Single Covalent Bond/Single Bond

The sharing of one pair of valence electrons.

Double Covalent Bond/Double Bond

The sharing of two pairs of valence electrons.

Structural Formula

Notation used to represent atoms and bonding.

Electronegativity

Atom's attraction for the electrons in a covalent bond.

Nonpolar Covalent Bond

Atoms share the electron equally.

Polar Covalent Bond

One atom is more electronegative, and the atoms do not share the electron equally.

Ion

A charged atom or molecule.

Cation

Positively charged ion.

Anion

Negatively charged ion.

Ionic Bond

Attraction between an anion and a cation.

Ionic Compounds (Salts)

Compounds formed by ionic bonds.

Hydrogen Bond

Forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom.

Van der Waals Interactions

Attractions between molecules that are close together as a result of these charges.

Solution

A liquid that is a completely homogenous mixture of substances.

Solvent

The dissolving agent of a solution.

Solute

The substance that is dissolved.

Aqueous Solution

One in which water is the solvent.

Hydration Shell

Sphere of water molecules around each ion when an ionic compound is dissolved in water.

Hydrophilic Substance

Substance that has an affinity for water.

Hydrophobic Substance

Substance that does not have an affinity for water.

Hydroxide Ion (OH-)

The molecule that lost the proton.

Hydronium Ion (H3O+)

The molecule with the extra proton.

Acid

Proton donor; increases the H+ concentration of a solution.

Base

Proton acceptor; reduces the H+ concentration of a solution.

Strong Acids and Bases

Acids and bases that dissociate completely in water.

Weak Acids and Bases

Acids and bases that do not fully ionize in solution.

pH

The negative logarithm of H+ concentration.

Buffers

Substances that minimize changes in concentrations of H+ and OH− in a solution.

Organic Chemistry

Is the study of compounds that contain carbon.

Hydrocarbons

Organic molecules consisting of only carbon and hydrogen.

Isomers

Compounds with the same molecular formula but different structures and properties.

Structural Isomers

Isomers with different covalent arrangements of their atoms.

Cis-Trans Isomers

Isomers that have the same covalent bonds but differ in spatial arrangements.

Enantiomers

Isomers that are mirror images of each other.

Functional Groups

Chemical groups that affect molecular function by being directly involved in chemical reactions.