Anatomy and Physiology - Chapter 2: Chemistry Comes Alive

Comprehensive vocabulary flashcards covering basic chemistry, chemical reactions, inorganic and organic compounds, biochemistry, and cellular energy from Chapter 2.

Matter

Anything that has mass and occupies space.

Energy

The capacity to do work or put matter into motion.

Kinetic Energy

Energy in action.

Potential Energy

Stored, inactive energy that has the capacity to do work.

Chemical Energy

Energy stored in the bonds of chemical substances.

Electrical Energy

Energy resulting from the movement of charged particles.

Mechanical Energy

Energy directly involved in moving matter.

Radiant Energy

Energy that travels in waves, such as heat, visible light, ultraviolet light, and X rays.

Element

A substance that cannot be broken down into simpler substances by ordinary chemical methods.

Atom

The smallest particle of an element that retains the unique physical and chemical properties of that element.

Proton

A positively charged subatomic particle located in the atomic nucleus, weighing $1\,amu$.

Neutron

An uncharged subatomic particle located in the atomic nucleus, weighing $1\,amu$.

Electron

A negatively charged subatomic particle orbiting the nucleus with virtually no weight ($0\,amu$).

Atomic Number

The number of protons in the nucleus of an atom, written as a subscript to the left of the atomic symbol.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Structural variations of an element whose atoms contain the same number of protons but differ in the number of neutrons.

Radioisotopes

Isotopes that decompose to more stable forms by giving off subatomic particles that release energy (radioactivity).

Molecule

A general term for two or more atoms held together by chemical bonds.

Compound

A specific molecule containing two or more different kinds of atoms bonded together.

Solution

A homogeneous mixture in which tiny solute particles are evenly distributed throughout a solvent, do not settle out, and do not scatter light.

Solvent

The substance present in the greatest amount in a solution, usually a liquid such as water.

Solute

The substance dissolved in a solvent, present in smaller amounts.

Colloid

A heterogeneous mixture (emulsion) containing solute particles larger than in a solution that scatter light but do not settle out, often undergoing sol-gel transformations.

Suspension

A heterogeneous mixture containing large, visible solutes that settle out of the solution over time.

Ionic Bond

A chemical bond involving the transfer of valence shell electrons from one atom to another, resulting in ions.

Covalent Bond

A chemical bond formed by the sharing of two or more valence shell electrons between two atoms.

Hydrogen Bond

An attractive force between an electropositive hydrogen atom of one molecule and an electronegative atom of another molecule.

Reactants

The substances entering into a chemical reaction together.

Products

The resulting chemical end products of a chemical reaction.

Synthesis Reaction

A chemical reaction in which atoms or molecules combine to form a larger, more complex molecule ($A + B \rightarrow AB$), utilized in anabolic processes.

Decomposition Reaction

A chemical reaction involving the breakdown of a molecule into smaller molecules or constituent atoms ($AB \rightarrow A + B$), involved in catabolic reactions.

Exchange Reaction

A displacement reaction in which bonds are both made and broken ($AB + C \rightarrow AC + B$).

Oxidation-Reduction Reaction

A redox reaction in which atoms are reduced when they gain electrons and oxidized when they lose electrons.

Exergonic Reaction

A reaction resulting in a net release of energy where products have less potential energy than reactants.

Endergonic Reaction

A reaction resulting in a net absorption of energy where products have more potential energy than reactants.

Catalyst

A substance that increases the rate of a chemical reaction without being chemically changed or becoming part of the product.

Inorganic Compound

A chemical compound that does not contain carbon, including water, salts, and many acids and bases.

Organic Compound

A carbon-containing compound (excluding $CO_2$ and $CO$) that is usually large and covalently bonded, such as carbohydrates, lipids, proteins, and nucleic acids.

Electrolyte

A substance that ionizes and dissociates into separate ions in water and can conduct electrical currents.

Acid

A proton donor that releases hydrogen ions ($H^+$) in solution.

Base

A proton acceptor that picks up $H^+$ ions and releases hydroxyl ions ($OH^-$) in solution.

pH Scale

A logarithmic measurement of hydrogen ion concentration $[H^+]$ in a solution, ranging from $0$ to $14$.

Buffer

A substance or system that resists abrupt and large swings in pH by binding $H^+$ when pH falls or releasing $H^+$ when pH rises.

Dehydration Synthesis

A chemical reaction that joins monomers by removing an $OH$ group from one monomer and an $H$ from the other, forming a covalent bond and releasing $H_2O$.

Hydrolysis

A chemical reaction that breaks polymers into monomers by adding a water molecule, attaching an $OH$ group to one monomer and an $H$ to the other.

Monosaccharide

A simple sugar containing three to seven carbon atoms with the general formula $(CH_2O)_n$, serving as the monomer unit for carbohydrates.

Disaccharide

A double sugar consisting of two linked monosaccharides formed by dehydration synthesis, such as sucrose, maltose, or lactose.

Polysaccharide

A polymer made up of long chains of linked monosaccharides, such as starch or glycogen.

Triglyceride

A fat molecule composed of three linear fatty acid chains bonded to a single glycerol molecule by dehydration synthesis.

Saturated Fatty Acid

A fatty acid chain in which all carbons are linked via single covalent bonds, maxing out hydrogen atoms and forming solids at room temperature.

Unsaturated Fatty Acid

A fatty acid chain containing one or more carbon-carbon double bonds, creating kinks that prevent close packing and maintaining a liquid state at room temperature.

Phospholipid

A modified triglyceride composed of glycerol, two fatty acids, and a phosphorus-containing group, featuring a polar hydrophilic head and nonpolar hydrophobic tails.

Steroid

A lipid molecule consisting of four interlocking hydrocarbon rings, with cholesterol serving as the structural baseline for all body steroids.

Eicosanoids

Lipids derived from arachidonic acid found in cell membranes, including prostaglandins that assist in blood clotting, blood pressure regulation, and inflammation.

Amino Acid

The monomer building block of proteins, consisting of an amine group, an acid group, and one of $20$ distinct $R$ groups.

Peptide Bond

The covalent bond that holds amino acid monomers together in a protein.

Fibrous Protein

A strandlike, water-insoluble, stable structural protein providing mechanical support and tensile strength, such as collagen or keratin.

Globular Protein

A compact, spherical, water-soluble functional protein containing active sites sensitive to environmental changes, such as enzymes and antibodies.

Protein Denaturation

The process in which globular proteins unfold and lose their functional 3-D shape and active site, often caused by increased temperature or decreased pH.

Enzyme

A globular protein that acts as a biological catalyst to accelerate chemical reactions by lowering activation energy.

Holoenzyme

A complete functional enzyme consisting of an apoenzyme (protein portion) and a cofactor (metal ion) or coenzyme (organic molecule).

Activation Energy

The energy required to initiate a chemical reaction.

Deoxyribonucleic Acid (DNA)

A double-stranded helical nucleic acid located in the cell nucleus that stores the genetic blueprint for protein synthesis.

Ribonucleic Acid (RNA)

A single-stranded linear nucleic acid containing ribose sugar and uracil that carries out DNA directives for protein synthesis outside the nucleus.

Adenosine Triphosphate (ATP)

An adenine-containing RNA nucleotide with three phosphate groups that captures chemical energy from glucose breakdown to power cellular work.