Acid: A hydrogen-containing substance that releases hydrogen ions (H+) in a solution.
Adenosine Triphosphate (ATP): A molecule that acts as the primary energy carrier in cells. It consists of the nitrogenous base adenine, the sugar ribose, and three phosphate groups.
Adipose tissue: A type of connective tissue that stores energy in the form of fat.
Amino acids: The building blocks of proteins, consisting of a central carbon atom bonded to an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R group) that determines its properties.
Anion: A negative ion.
Atoms: The smallest amount of an element.
Atomic number: The number of protons in the nucleus of an atom of that element. It uniquely identifies the element.
Base: A molecule in a solution that accepts hydrogen ions (H+) already present in the solution or releases hydroxyl ions (OH–).
Biomolecules: Organic molecules that are essential for life including carbohydrates, proteins, lipids, and nucleic acids.
Bond: A weak or strong electrical attraction that holds atoms in the same area.
Buffer: A solution that resists changes in its pH when small amounts of an acid or base are added to it.
Carbohydrates: Provide energy to the body through glucose.
Catalyst: A substance that increases the rate and force at which atoms, ions, and molecules collide, thereby increasing the chances that the electrons in their valence shells will interact.
Cation: A positive ion.
Cellulose: A component of plant cell walls, commonly known as “fiber” in the diet.
Colloid: A mixture that is like a heavy solution
Compound: A substance composed of two or more elements joined by chemical bonds.
Covalent bond: Type of bond that forms when electrons are shared between two elements.
Dehydration synthesis: The elimination of water to combine molecules.
Disaccharides: When two monosaccharides join together with a covalent bond.
Double bond: Type of bond in which two pairs of electrons are shared.
Double helix: Two strands of nucleotides wind around each other like a spiral staircase.
Electrons: Very small, negatively-charged particles found outside of the atom’s nucleus. They have no mass and a charge of -1.
Electron shell: A layer of electrons that circle the nucleus at a distinct energy level.
Electron transfer: The movement of electrons from one element to another.
Element: A pure substance that cannot be created or broken down by ordinary chemical means or transformed chemically into different substances.
Enzyme: Catalyst which help speed up chemical reactions.
Essential amino acids: Amino acids which cannot be made by the body and must be consumed in the diet.
Glucose: A simple sugar.
Glycogen: The storage form of glucose in humans and other animals and is made up of monomers (building blocks) of glucose bonded together into long chains.
Heat sink: A device or material that absorbs and dissipates heat from an object to prevent overheating.
Homogeneous: Solutes that are distributed evenly throughout a solution.
Hydrogen bond: A weak to moderate attractive force that occurs between a hydrogen atom, which is covalently bonded to a more electronegative atom (like oxygen, nitrogen, or fluorine), and another electronegative atom with a lone pair of electrons.
Hydrophobic: A term used to describe substances that repel or do not dissolve in water.
Hydrophilic: a substance or molecule that has an affinity for water.
Ion: An atom that does not contain equal numbers of protons and electrons.
Ionic bond: A chemical bond formed between a cation and anion.
Ionic compounds: Compounds composed of ions, also known as salts.
Inorganic compounds: Compounds which do not contain carbon-hydrogen bonds and rarely contain carbon.
Isotope: Different forms of an element, distinguished from one another by different numbers of neutrons.
Lipids: A diverse group of organic molecules that are primarily hydrophobic and insoluble in water. They include fats, oils, phospholipids, steroids, and waxes, and they play essential roles in energy storage, cell membrane structure, hormone production, and insulation.
Liquid solution: Consists of a substance called a solute dissolved into a solvent.
Mass number: The total number of protons and neutrons in the element’s nucleus.
Matter: Anything that takes up space and has mass.
Molecule: A stable grouping of two or more atoms held together by chemical bonds.
Monosaccharides: Simple sugars, the most common of which is glucose.
Mixture: A combination of two or more substances that maintain their own chemical identity and are not chemically bonded into a larger substance.
Neutrons: Found in the center or nucleus of an atom, do not have a charge so are neutral and they have a mass of 1.
Nonpolar covalent bond: Type of bonds which form between two atoms of the same element or between different elements that share the electrons equally.
Nucleotides: The basic building block of nucleic acids like DNA and RNA
Octet rule: A rule that states that an atom will give up, gain, or share electrons with another atom so that it ends up with eight electrons in its own valence shell.
Organic compounds: Molecules that contain both carbon and hydrogen.
Peptide: A very short chain of amino acids.
Peptide bond: A covalent bond between two amino acids that forms by dehydration synthesis
Periodic table: A chart that organizes all known chemical elements based on their atomic number, electron configuration, and recurring chemical properties.
pH: A measure of the concentration of hydrogen (H+) ions.
Phospholipids: The main component of cell membranes, which protect cells from environmental damage and allow for cellular processes.
Polar covalent bonds: Type of bond formed between two or more different elements which do not share electrons equally.
Polypeptides: Strands containing fewer than 100 amino acids.
Polysaccharide: A long chain of monosaccharides linked by covalent bonds.
Plasma: Watery portion of the blood
Prostaglandin: A lipid compound derived from fatty acids that acts as a signaling molecule in the body.
Protein: An organic molecule made up of building blocks called amino acids that are linked by peptide bonds.
Protons: Positively-charged particles found in the nucleus or center of the atom.
Radioactive isotope: Also known as a radioisotope, is an atom with an unstable nucleus that undergoes radioactive decay, emitting radiation in the form of alpha particles, beta particles, or gamma rays. This process occurs as the atom seeks a more stable energy state.
RNA (Ribonucleic Acid): A single-stranded nucleic acid that plays a crucial role in the synthesis of proteins.
Saturated fats: A type of fat in which all the carbon atoms in the fatty acid chains are connected by single bonds, meaning they are “saturated” with hydrogen atoms.
Sedimentation: Separation of particles from a suspension.
Single bond: Type of bond in which two atoms share one pair (or two individual) electrons.
Solute: A substance that is dissolved in a solvent to form a solution.
Solvent: A substance, typically a liquid, that dissolves a solute to form a solution.
Starch: The storage form of glucose in plants and is relatively easy for humans to digest.
Steroids: A class of lipids characterized by their hydrophobic nature and insolubility in water. They have a distinct chemical structure consisting of four interconnected rings of carbon atoms.
Suspension: A liquid mixture in which a heavier substance is suspended temporarily in a liquid, but over time, the substance settles out.
Trans fats: A type of unsaturated fat that have been artificially modified through a process called hydrogenation, which adds hydrogen to liquid oils to make them more solid and shelf-stable.
Triglyceride: A type of lipid (fat) composed of one glycerol molecule and three fatty acid chains. It is the main form of stored fat in the body and a major source of energy.
Triple bond: Type of bond in which three pairs of electrons are shared between atoms.
Universal solvent: A term commonly used to describe water, due to its ability to dissolve a wide variety of substances.
Unsaturated fats: A type of fat in which the fatty acid chains contain one or more double bonds between carbon atoms, meaning they are not fully saturated with hydrogen atoms.
Valence shell: An atom’s outermost electron shell.
