Essentials Of Human Anatomy & Physiology Chapter 2

Front 1

Radiant (electromagnetic) energy

Back 1

Energy form that travels in waves.

Front 2

Exchange (displacement) reaction

Back 2

Chemical reaction in which bonds are both made and broken; atoms become combined with different atoms.

Front 3

Covalent bond

Back 3

Chemical bond created by electron sharing between atoms.

Front 4

Chemical bond

Back 4

An energy relationship holding atoms together; involves the interaction of electrons.

Front 5

Acid

Back 5

A substance that releases hydrogen ions when in solution (compare with Base); a proton donor.

Front 6

Atomic weight

Back 6

The average of the mass numbers of all the isotopes of an element.

Front 7

pH

Back 7

The symbol for hydrogen ion concentration; a measure of the relative acidity or alkalinity of a solution.

Front 8

Radioactivity

Back 8

The process of spontaneous decay seen in some of the heavier isotopes, during which particles or energy is emitted from the atomic nucleus; results in the atom becoming more stable.

Front 9

Compound

Back 9

Substance composed of two or more different elements, the atoms of which are chemically united.

Front 10

Proton

Back 10

Subatomic particle that bears a positive charge; located in the atomic nucleus.

Front 11

Atom

Back 11

The smallest part of an element; indivisible by ordinary chemical means.

Front 12

Ion

Back 12

Atom with a positive or negative electric charge.

Front 13

Hydrogen bond

Back 13

Weak bond in which a hydrogen atom forms a bridge between two electron-hungry atoms. An important intramolecular bond.

Front 14

Triglycerides

Back 14

Fats and oils composed of fatty acids and glycerol; are the body's most concentrated source of energy fuel; also known as neutral fats.

Front 15

Lipid

Back 15

Organic compound formed of carbon, hydrogen, and oxygen; examples are fats and cholesterol.

Front 16

Cholesterol

Back 16

Steroid found in animal fats as well as in most body tissues; made by the liver.

Front 17

Atomic mass number

Back 17

Sum of the number of protons and neutrons in the nucleus of an atom.

Front 18

Chemical reaction

Back 18

Process in which molecules are formed, changed, or broken down.

Front 19

Ionic bond

Back 19

Chemical bond formed by electron transfer between atoms.

Front 20

Amino acid

Back 20

Organic compound containing nitrogen, carbon, hydrogen, and oxygen; building block of protein.

Front 21

Decomposition reaction

Back 21

Chemical reaction in which a molecule is broken down into smaller molecules or its constituent atoms.

Front 22

Matter

Back 22

Anything that occupies space and has mass.

Front 23

Dehydration synthesis

Back 23

Process by which a large molecule is synthesized by covalently bonding smaller molecules together.

Front 24

Carbohydrate

Back 24

Organic compound composed of carbon, hydrogen, and oxygen; includes starches, sugars, cellulose.

Front 25

Hydrolysis

Back 25

Process in which water is used to split a substance into smaller particles.

Front 26

Kinetic energy

Back 26

The energy of motion or movement, e.g., the constant movement of atoms, or the push given to a swinging door that sets it into motion.

Front 27

Synthesis (combination) reaction

Back 27

A chemical reaction in which larger, more complex atoms or molecules are formed from simpler ones.

Front 28

Neutron

Back 28

Uncharged subatomic particle; found in the atomic nucleus.

Front 29

Protein

Back 29

Complex substance containing carbon, oxygen, hydrogen, and nitrogen; composes 10% to 30% of cell mass.

Front 30

Polysaccharide

Back 30

Literally, many sugars, a polymer of linked monosaccharides; e.g., starch, glycogen.

Front 31

Organic compound

Back 31

Any compound composed of atoms (some of which are carbon) held together by covalent (shared electron) bonds.

Front 32

Radioisotope

Back 32

Isotope that exhibits radioactive behavior.

Front 33

Monosaccharide

Back 33

Literally, one sugar; building block of carbohydrates; e.g., glucose.

Front 34

Glycerol

Back 34

A modified simple sugar (a sugar alcohol).

Front 35

Molecule

Back 35

Particle consisting of two or more atoms joined together by chemical bonds.

Front 36

Glycogen

Back 36

Main carbohydrate stored in animal cells; a polysaccharide.

Front 37

Atomic symbol

Back 37

The one- or two-letter symbol used to indicate an element; usually the first letter(s) of the element's name.

Front 38

Energy

Back 38

The capacity to do work; may be stored (potential energy) or in action (kinetic energy).

Front 39

Electrical energy

Back 39

Energy formed by the movement of charged particles across cell membranes.

Front 40

Inorganic compound

Back 40

Chemical substances that do not contain carbon, including water, salts, and many acids and bases.

Front 41

Element

Back 41

One of a limited number of unique varieties of matter that composes substances of all kinds; e.g., carbon, hydrogen, oxygen.

Front 42

Phospholipid

Back 42

Modified lipid containing phosphorus.

Front 43

Adenosine triphosphate (ATP)

Back 43

Organic molecule that stores and releases chemical energy for use in body cells.

Front 44

Isotopes

Back 44

Different atomic forms of the same element, vary only in the number of neutrons they contain; the heavier species tend to be radioactive.

Front 45

Polypeptide

Back 45

A chain of amino acids.

Front 46

Base

Back 46

A substance capable of binding with hydrogen ions; a proton acceptor.

Front 47

Disaccharide

Back 47

Literally, double sugar; e.g., sucrose, lactose.

Front 48

Valence shell

Back 48

Outermost electron shell (energy level) of an atom that contains electrons.

Front 49

Fatty acids

Back 49

Linear chains of carbon and hydrogen atoms (hydrocarbon chains) with an organic acid group at one end. A constituent of fat.

Front 50

Salt

Back 50

Ionic compound that dissociates into charged particles (other than hydrogen or hydroxyl ions) when dissolved in water.

Front 51

Nucleic acid

Back 51

Class of organic molecules that includes DNA and RNA.

Front 52

Electron

Back 52

Negatively charged subatomic particle; orbits the atom's nucleus.

Front 53

Atomic number

Back 53

The number of protons in an atom.

Front 54

Steriods

Back 54

Groups of chemical substances including certain hormones and cholesterol; they are fat soluble and contain little oxygen.

Front 55

Mechanical energy

Back 55

The energy directly involved in moving matter; e.g., in bicycle riding, the legs provide the mechanical energy that moves the pedals.

Front 56

Polar molecules

Back 56

Nonsymmetrical molecules that contain electrically unbalanced atoms.

Front 57

Nucleotide

Back 57

Building block of nucleic acids; consists of a sugar, a nitrogen-containing base, and a phosphate group.

Front 58

Glucose

Back 58

Principal blood sugar; a hexose.

Front 59

Chemical energy

Back 59

Energy stored in the bonds of chemical substances.