Unit 1 Vocabulary Flashcards

Water, Solutions, and Chemistry

Acid - molecule that donates hydrogen ions and increases the concentration of hydrogen ions in a solution.
- Significance: defines acidity; increases
- Example: acids release \text{H}^+ in solution.
Base - molecule that donates hydroxide ions or otherwise binds excess hydrogen ions and decreases the concentration of hydrogen ions in a solution.
- Significance: opposes acidity; raises pH by reducing \text{H}^+ availability.
- Example: bases can accept protons or release \text{OH}^-.
pH - a measurement of how acidic or basic a solution is; indicates the concentration of hydrogen ions ((\mathrm{H^+})) in a substance.
- Mathematical relation: \mathrm{pH} = -\log [\mathrm{H^+}]\,.
Electronegativity - ability of some elements to attract electrons (often of hydrogen atoms), acquiring partial negative charges in molecules and creating partial positive charges on the hydrogen atoms.
- Consequences: drives bond polarity and many interactions in biology.
Ion - atom or chemical group that does not contain equal numbers of protons and electrons.
Ionic Bond - chemical bond that forms between ions with opposite charges (cations and anions).
Covalent Bond - type of strong bond formed between two atoms of the same or different elements; forms when electrons are shared between atoms.
Hydrogen Bond - weak bond between slightly positively charged hydrogen atoms and slightly negatively charged atoms in other molecules.
Capillary Action - occurs because water molecules are attracted to charges on the inner surfaces of narrow tubular structures such as glass tubes, drawing the water molecules to the sides of the tubes.
Adhesion - attraction between water molecules and other molecules.
Cohesion - intermolecular forces between water molecules caused by the polar nature of water; responsible for surface tension.
Surface Tension - tension at the surface of a body of liquid that prevents the molecules from separating; created by the cohesive forces between the molecules of the liquid.
Density of water - weight of water per unit volume.
Water - universal solvent (Water-universal solvent).
Hydrophilic - describes ions or polar molecules that interact well with other polar molecules such as water.
Hydrophobic - describes uncharged nonpolar molecules that do not interact well with polar molecules such as water.
Polar Molecule - molecule where the electrons are distributed unevenly, creating distinct regions of positive and negative charge.
Non-Polar Molecule - molecule where the electrical charge is evenly distributed across its structure, meaning there are no distinct positive or negative poles, and the molecule has no separation of charge due to its symmetrical arrangement of atoms with similar electronegativity.
Ion - see above (ion).
Solvent - substance capable of dissolving another substance.
Solute - substance dissolved in a liquid to form a solution.
Solution - a homogeneous mixture of two or more substances.
Monomer - smallest unit of larger molecules called polymers.
Polymer - chain of monomer residues that is linked by covalent bonds; polymerization is the process of polymer formation from monomers by condensation.
Macromolecule - large molecule, typically formed by the joining of smaller molecules.
Carbohydrate - biological macromolecule in which the ratio of carbon to hydrogen and to oxygen is 1:2:1; serve as energy sources and structural support in cells.
Monosaccharide - single unit or monomer of carbohydrates.
Disaccharide - two sugar monomers that are linked together by a glycosidic bond.
Polysaccharide - long chain of monosaccharides may be branched or unbranched.
Glycosidic Bond - bonds formed by a dehydration reaction between two monosaccharides with the elimination of a water molecule.
Dehydration Synthesis - (also condensation) reaction that links monomer molecules together, releasing a molecule of water for each bond formed.
Hydrolysis - reaction that causes breakdown of larger molecules into smaller molecules with the utilization of water.
Deoxyribose sugar - five-carbon sugar that is a key component of DNA or deoxyribonucleic acid.
Ribose Sugar - sugar used in RNA to make up the “backbone”.
DNA - double-helical molecule that carries the hereditary information of the cell.
RNA - single-stranded, often internally base paired, molecule that is involved in protein synthesis.
Nucleic Acid - biological macromolecule that carries the genetic blueprint of a cell and carries instructions for the functioning of the cell.
Nucleotide - monomer of nucleic acids; contains a pentose sugar, one or more phosphate groups, and a nitrogenous base.
Purines - type of nitrogenous base in DNA and RNA; adenine and guanine are purines.
Pyrimidines - type of nitrogenous base in DNA and RNA; cytosine, thymine, and uracil are pyrimidines.
Phosphate Group - PO(_4).
Phospholipid - major constituent of the membranes; composed of two fatty acids and a phosphate-containing group attached to a glycerol backbone.
Triglyceride - fat molecule; consists of three fatty acids linked to a glycerol molecule.
Lipid - macromolecule that is nonpolar and insoluble in water.
Fatty Acid - carboxylic acid consisting of a hydrocarbon chain and a terminal carboxyl group.
Glycerol - three-carbon alcohol with a hydroxyl group attached to each carbon.
Phospholipid - see above.
Cholesterol - a type of fate made by the body from saturated fats; a minor part of fat in foods.
Saturated Fat - long chain of hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized.
Unsaturated Fat - long-chain hydrocarbon that has one or more double bonds in the hydrocarbon chain.
Hormonal Proteins - provide coordination of an organism’ activities (i.e. insulin).
Enzyme Proteins - catalyze reactions.
Defensive Proteins - proteins that help organisms fight infection, heal wounds, and evade predators.
Structural Proteins - provide physical stability and movement.
Storage Proteins - store amino acids for later use.
Transport Proteins - membrane protein that facilitates passage of a substance across a membrane by binding it.
Receptor Proteins - a protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell, used in communication and cell signaling.
Motor Proteins - a protein that interacts with cytoskeletal elements and other cell components, producing movements of the cell or parts of the cell, used for movement.
Protein - biological macromolecule composed of one or more chains of amino acids.
Amino Acid - monomer of a protein; has a central carbon or alpha carbon to which an amino group, a carboxyl group, a hydrogen, and an R group or side chain is attached; the R group is different for the most common 20 amino acids.
Amine Group - NH(_2).
Carboxyl Group - -\mathrm{COOH}.
Hydroxyl Group - \mathrm{OH^-}.
R-Group - a functional group that defines a particular amino acid and gives it special properties.
Alpha Helix - type of secondary structure of proteins formed by folding of the polypeptide into a helix shape with hydrogen bonds stabilizing the structure.
Beta Sheet - secondary structure found in proteins in which “pleats” are formed by hydrogen bonding between atoms on the backbone of the polypeptide chain.
Primary Structure - linear sequence of amino acids in a protein.
Secondary Structure - includes alpha helices and beta sheets as the first level of folding.
Tertiary Structure - three-dimensional conformation of a protein, including interactions between secondary structural elements; formed from interactions between amino acid side chains.
Quaternary Structure - association of discrete polypeptide subunits in a protein.
Denaturation - loss of shape in a protein as a result of changes in temperature, pH, or exposure to chemicals.
Protein - see above.
Monomer - see above (monomer).
Polymer - see above (polymer).
Macromolecule - see above (macromolecule).
Nucleic Acid - see above (nucleic acid).
Water - see above (water).
Alpha Helix - see above (alpha helix).
Beta Sheet - see above (beta sheet).
Primary Structure - see above (primary structure).
Secondary Structure - see above (secondary structure).
Tertiary Structure - see above (tertiary structure).
Quaternary Structure - see above (quaternary structure).
Capillary Action - see above (capillary action).

Note: The list above preserves the sequence and definitions from the transcript and adds clarifications and structural notes where helpful for study. LaTeX is used for chemical formulas and mathematical expressions, for example: \mathrm{pH} = -\log [\mathrm{H^+}], \mathrm{-COOH}, \mathrm{NH2}, \mathrm{OH^-}, and \mathrm{PO4}.