- acid
- a substance that donates hydrogen ions and therefore lowers pH
- adhesion
- the attraction between water molecules and molecules of a different substance
- amino acid
- a monomer of a protein
- anion
- a negative ion formed by gaining electrons
- atomic number
- the number of protons in an atom
- base
- a substance that absorbs hydrogen ions and therefore raises pH
- buffer
- a solution that resists a change in pH by absorbing or releasing hydrogen or hydroxide ions
- carbohydrate
- a biological macromolecule in which the ratio of carbon to hydrogen to oxygen is 1:2:1; carbohydrates serve as energy sources and structural support in cells
- cation
- a positive ion formed by losing electrons
- cellulose
- a polysaccharide that makes up the cell walls of plants and provides structural support to the cell
- chemical bond
- an interaction between two or more of the same or different elements that results in the formation of molecules
- chitin
- a type of carbohydrate that forms the outer skeleton of arthropods, such as insects and crustaceans, and the cell walls of fungi
- cohesion
- the intermolecular forces between water molecules caused by the polar nature of water; creates surface tension
- covalent bond
- a type of strong bond between two or more of the same or different elements; forms when electrons are shared between elements
- denaturation
- the loss of shape in a protein as a result of changes in temperature, pH, or exposure to chemicals
- deoxyribonucleic acid (DNA)
- a double-stranded polymer of nucleotides that carries the hereditary information of the cell
- disaccharide
- two sugar monomers that are linked together by a glycodsidic bond
- electron
- a negatively charged particle that resides outside of the nucleus in the electron orbital; lacks functional mass and has a charge of –1
- electron transfer
- the movement of electrons from one element to another
- element
- one of 118 unique substances that cannot be broken down into smaller substances and retain the characteristic of that substance; each element has a specified number of protons and unique properties
- enzyme
- a catalyst in a biochemical reaction that is usually a complex or conjugated protein
- evaporation
- the release of water molecules from liquid water to form water vapor
- fat
- a lipid molecule composed of three fatty acids and a glycerol (triglyceride) that typically exists in a solid form at room temperature
- glycogen
- a storage carbohydrate in animals
- hormone
- a chemical signaling molecule, usually a protein or steroid, secreted by an endocrine gland or group of endocrine cells; acts to control or regulate specific physiological processes
- hydrogen bond
- a weak bond between partially positively charged hydrogen atoms and partially negatively charged elements or molecules
- hydrophilic
- describes a substance that dissolves in water; water-loving
- hydrophobic
- describes a substance that does not dissolve in water; water-fearing
- ion
- an atom or compound that does not contain equal numbers of protons and electrons, and therefore has a net charge
- ionic bond
- a chemical bond that forms between ions of opposite charges
- isotope
- one or more forms of an element that have different numbers of neutrons
- lipids
- a class of macromolecules that are nonpolar and insoluble in water
- litmus paper
- filter paper that has been treated with a natural water-soluble dye so it can be used as a pH indicator
- macromolecule
- a large molecule, often formed by polymerization of smaller monomers
- mass number
- the number of protons plus neutrons in an atom
- matter
- anything that has mass and occupies space
- monosaccharide
- a single unit or monomer of carbohydrates
- neutron
- a particle with no charge that resides in the nucleus of an atom; has a mass of 1
- nonpolar covalent bond
- a type of covalent bond that forms between atoms when electrons are shared equally between atoms, resulting in no regions with partial charges as in polar covalent bonds
- nucleic acid
- a biological macromolecule that carries the genetic information of a cell and carries instructions for the functioning of the cell
- nucleotide
- a monomer of nucleic acids; contains a pentose sugar, a phosphate group, and a nitrogenous base
- nucleus
- (chemistry) the dense center of an atom made up of protons and (except in the case of a hydrogen atom) neutrons
- octet rule
- states that the outermost shell of an element with a low atomic number can hold eight electrons
- oil
- an unsaturated fat that is a liquid at room temperature
- periodic table of elements
- an organizational chart of elements, indicating the atomic number and mass number of each element; also provides key information about the properties of elements
- pH scale
- a scale ranging from 0 to 14 that measures the approximate concentration of hydrogen ions of a substance
- phospholipid
- a major constituent of the membranes of cells; composed of two fatty acids and a phosphate group attached to the glycerol backbone
- polar covalent bond
- a type of covalent bond in which electrons are pulled toward one atom and away from another, resulting in slightly positive and slightly negative charged regions of the molecule
- polypeptide
- a long chain of amino acids linked by peptide bonds
- polysaccharide
- a long chain of monosaccharides; may be branched or unbranched
- protein
- a biological macromolecule composed of one or more chains of amino acids
- proton
- a positively charged particle that resides in the nucleus of an atom; has a mass of 1 and a charge of +1
- radioactive isotope
- an isotope that spontaneously emits particles or energy to form a more stable element
- ribonucleic acid (RNA)
- a single-stranded polymer of nucleotides that is involved in protein synthesis
- saturated fatty acid
- a long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized
- solvent
- a substance capable of dissolving another substance
- starch
- a storage carbohydrate in plants
- steroid
- a type of lipid composed of four fused hydrocarbon rings
- surface tension
- the cohesive force at the surface of a body of liquid that prevents the molecules from separating
- temperature
- a measure of molecular motion
- trans-fat
- a form of unsaturated fat with the hydrogen atoms neighboring the double bond across from each other rather than on the same side of the double bond
- triglyceride
- a fat molecule; consists of three fatty acids linked to a glycerol molecule
- unsaturated fatty acid
- a long-chain hydrocarbon that has one or more than one double bonds in the hydrocarbon chain
- van der Waals interaction
- a weak attraction or interaction between molecules caused by slightly positively charged or slightly negatively charged atoms