#2 Uncovering Chemistry’s Role in Vet Care

Acid

A substance that increases hydrogen ion (H+) concentration in solution; has pH below 7. Clinically, acids donate protons and can neutralize bases.

Acidity

The degree to which a solution is acidic (pH below 7); measured by hydrogen ion concentration. Clinically refers to acid-base imbalance toward the acidic side.

Activation Energy

The minimum energy required for a chemical reaction to begin. Clinically, the energy barrier that enzymes lower to make biological reactions occur at body temperature.

Active Site

The specific region on an enzyme where substrate molecules bind and reactions occur. Clinically, the functional area that determines enzyme specificity and activity.

Alkalinity

The degree to which a solution is basic (pH above 7); caused by low hydrogen ion concentration. Clinically refers to acid-base imbalance toward the basic side.

Anion

An ion with negative electrical charge, such as chloride (Cl-) or hydroxide (OH-). Clinically important for maintaining electrical neutrality and proper cell function.

Atom

The smallest unit of an element that retains all chemical properties of that element; consists of protons, neutrons, and electrons.

Base (Alkaline)

A substance that provides hydroxide ions (OH-) or reduces hydrogen ion concentration; has pH above 7. Clinically, bases accept protons and neutralize acids.

Catalyst

A substance that speeds up chemical reactions without being consumed in the process. In biology, enzymes serve as biological catalysts for metabolic processes.

Cation

An ion with positive electrical charge, such as sodium (Na+), potassium (K+), or calcium (Ca2+). Essential for nerve function, muscle contraction, and fluid balance.

Compound

A substance formed when two or more different elements bond together chemically in fixed proportions. Has properties different from its component elements.

Covalent Bond

A chemical bond where atoms share electrons to achieve stability. Forms the backbone of most biological molecules including proteins, carbohydrates, and DNA.

Denaturation

The process of protein unfolding and losing its natural three-dimensional structure and function due to heat, pH changes, or chemicals.

Element

A pure substance that cannot be broken down into simpler substances by chemical reactions. Examples include oxygen, hydrogen, carbon, sodium, and potassium.

Enzyme

A specialized protein that speeds up chemical reactions in the body without being consumed. Acts as biological catalyst with specific substrate requirements.

Hydrogen Bond

A weak attraction between hydrogen atoms and nearby electronegative atoms like oxygen or nitrogen. Gives water its unique properties.

Hydrogen Ion (H+)

A positively charged hydrogen atom that determines solution acidity. Higher H+ concentration means lower pH and greater acidity.

Hydroxide Ion (OH-)

A negatively charged ion consisting of oxygen and hydrogen that makes solutions more basic. Neutralizes acids by combining with hydrogen ions.

Induced-Fit Model

A refined enzyme model showing that enzymes slightly change shape to better accommodate their substrates, like a flexible glove fitting a hand.

Ion

An atom or molecule with electrical charge due to gaining or losing electrons. Can be positively charged (cation) or negatively charged (anion).

Ionic Bond

A chemical bond formed when one atom loses electrons and another gains them, creating oppositely charged ions that attract each other.

Ionization

The process of atoms or molecules gaining or losing electrons to become charged particles. Occurs naturally in water and biological systems.

Isotope

Atoms of the same element with different numbers of neutrons. Some isotopes are radioactive and used in medical treatments.

Lock-and-Key Model

A model describing enzyme specificity where enzymes and substrates fit together precisely, like a key fitting only one lock.

Matter

Anything that has mass and takes up space; composed of atoms and molecules. Includes all physical substances in solid, liquid, or gas form.

Molecule

The smallest unit of a compound formed when atoms bond together covalently. Retains all chemical properties of the compound.

Neutron

A particle with no electrical charge found in the atomic nucleus alongside protons. Different neutron numbers create isotopes of elements.

Nonpolar Covalent Bond

A covalent bond where electrons are shared equally between atoms, creating no partial charges on the molecule.

Periodic Table

An organized chart of all known elements arranged by atomic number and chemical properties. Predicts element behavior and interactions.

pH

A measure of hydrogen ion concentration ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral. Logarithmic scale.

Polar Covalent Bond

A covalent bond where electrons are shared unequally, creating partial positive and negative charges on different parts of the molecule.

Primary Structure

The specific sequence of amino acids in a protein chain. Determines all higher levels of protein structure and function.

Protein

Large molecules made of amino acid chains that control structure and function in cells. Include enzymes, antibodies, and structural components.

Proton

A positively charged particle found in the atomic nucleus. The number of protons determines what element an atom represents.

Quaternary Structure

The arrangement of multiple protein chains working together to form a functional unit. Highest level of protein organization.

Secondary Structure

Local folding patterns in proteins such as alpha-helices or beta-sheets, formed by hydrogen bonds between amino acids.

Substrate

The molecule that an enzyme acts upon during a chemical reaction. Fits into the enzyme's active site to undergo transformation.

Tertiary Structure

The overall three-dimensional shape of a protein formed by interactions between amino acid side chains. Determines protein function.

Valence Electrons

Electrons in the outermost energy level of an atom that participate in chemical bonding. Determine how atoms will bond with others.