Ch. 2 Chemistry Comes Alive Flashcards
(277 cards)
1
Q
What are the four elements that form the bulk of body matter?
A
Oxygen, Carbon, Hydrogen, Nitrogen
2
Q
What is the definition of an atom?
A
The smallest unit of an element that retains the properties of that element.
3
Q
Which type of chemical bond involves the sharing of electron pairs between atoms?
A
Covalent bond
4
Q
What are the three major types of chemical reactions?
A
Synthesis, decomposition, and exchange
5
Q
How are large organic compounds made and broken down?
A
Made by dehydration synthesis and broken down by hydrolysis
6
Q
What is the primary function of carbohydrates in the body?
A
Provide an easily used energy source
7
Q
What are the building blocks of proteins?
A
Amino acids
8
Q
What is the role of ATP in cell metabolism?
A
Transfers energy to other compounds
9
Q
What are the three types of chemical bonds?
A
Ionic, covalent, and hydrogen bonds
10
Q
What is the main function of ATP in the cell?
A
Transferring energy to other compounds
11
Q
What are the building blocks of carbohydrates?
A
Simple sugars (monosaccharides)
12
Q
What is the role of enzymes in the body?
A
They act as catalysts to speed up chemical reactions
13
Q
What is the difference between DNA and RNA?
A
DNA stores genetic information, while RNA helps in transmitting and expressing it
14
Q
Matter
A
The substance of which the universe is composed
15
Q
Energy
A
The capacity to do work or put matter into motion
16
Q
Atom
A
The smallest unit of an element that retains the properties of that element
17
Q
Isotope
A
Variants of a particular chemical element that differ in neutron number
18
Q
Radioisotope
A
An isotope that has an unstable nucleus and emits radiation
19
Q
Dehydration synthesis
A
A chemical reaction that builds up molecules by losing water molecules
20
Q
Hydrolysis
A
A chemical process that splits a molecule by adding water
21
Q
What state of matter has a definite shape and volume?
A
Solid
22
Q
What is the main difference between mass and weight?
A
Mass remains constant while weight varies with gravity
23
Q
What is energy defined as?
A
The capacity to do work or to put matter into motion
24
Q
What type of energy is stored and has the potential to do work?
A
Potential energy
25
What type of energy is involved in moving matter?
Mechanical energy
26
What form of energy is stored in the bonds of chemical substances?
Chemical energy
27
What is the most useful form of energy in living systems?
Chemical energy in the form of ATP
28
What type of energy results from the movement of charged particles?
Electrical energy
29
What type of energy travels in waves and includes visible light?
Radiant energy
30
What are the three states of matter?
Solid, liquid, and gas.
31
What is kinetic energy?
Energy in action.
32
What is potential energy?
Stored energy that has the potential to do work.
33
Kinetic Energy
Energy in action.
34
Potential Energy
Stored energy that has the potential to do work.
35
What are the four elements that form the bulk of body matter?
Carbon, Oxygen, Hydrogen, Nitrogen
36
What is the definition of a chemical element?
A unique substance that cannot be broken down into simpler substances by ordinary chemical methods
37
Which subatomic particle has a positive charge?
Proton
38
What is the atomic number of an element?
The number of protons in its nucleus
39
What is the mass number of an atom?
The sum of the masses of its protons and neutrons
40
What is an isotope?
A structural variation of an element with the same number of protons but different numbers of neutrons
41
What is the primary function of oxygen in the human body?
Needed for the production of cellular energy (ATP)
42
What is the role of calcium in the human body?
Required for muscle contraction, conduction of nerve impulses, and blood clotting
43
What is the charge of a neutron?
Neutral
44
What is the term for the process of atomic decay in radioisotopes?
Radioactivity
45
Chemical element
A unique substance that cannot be broken down into simpler substances by ordinary chemical methods
46
Proton
A subatomic particle with a positive charge found in the nucleus of an atom
47
Neutron
A subatomic particle with no charge found in the nucleus of an atom
48
Electron
A subatomic particle with a negative charge that orbits the nucleus of an atom
49
Atomic mass
The sum of the masses of an atom's protons and neutrons
50
What is the most abundant element in the human body by mass?
Oxygen
51
What is the primary function of potassium in the body?
Necessary for conduction of nerve impulses and muscle contraction
52
What is a molecule?
A combination of two or more atoms held together by chemical bonds
53
Which of the following is an example of a compound?
Water (H2O)
54
What type of mixture is blood?
Suspension
55
What is a characteristic of a solution?
The solute particles are very tiny and do not settle out.
56
Which of the following is a homogeneous mixture?
Air
57
What is the main characteristic of colloids?
They scatter light and do not settle out.
58
What is the concentration unit commonly used to measure blood glucose levels?
Milligrams per deciliter (mg/dl)
59
What is Avogadro's number?
6.02 × 10^23
60
What is a sol-gel transformation?
The reversible change from a fluid (sol) state to a solid (gel) state in colloids.
61
What is a molecule?
A combination of two or more atoms held together by chemical bonds.
62
What is the difference between a compound and a mixture?
Compounds are chemically pure substances with identical molecules, while mixtures are physically intermixed substances without chemical bonding.
63
What is a solution?
A homogeneous mixture where the solute particles are very tiny and do not settle out.
64
What is a colloid?
A heterogeneous mixture with solute particles larger than those in a solution, which do not settle out but scatter light.
65
What is a suspension?
A heterogeneous mixture with large, often visible solutes that tend to settle out.
66
How can you distinguish a mixture from a compound?
Mixtures can be separated by physical means and do not involve chemical bonding, whereas compounds can only be separated by chemical means.
67
Solvent
The substance present in the greatest amount in a solution, usually a liquid.
68
Solute
A substance present in smaller amounts in a solution, dissolved in the solvent.
69
Molarity
A measure of concentration, defined as moles of solute per liter of solution.
70
Avogadro’s number
The number of particles in one mole of a substance, equal to 6.02 × 10^23.
71
What is the primary role of electrons in chemical bonding?
To achieve stability by filling the outermost energy level
72
According to the octet rule, how many electrons do atoms tend to have in their valence shell to be stable?
8
73
Which type of chemical bond involves the sharing of electron pairs between atoms?
Covalent bonds
74
What is the main characteristic of ionic bonds?
Attraction between two oppositely charged ions
75
Which type of bond is the weakest among the three major types of chemical bonds?
Hydrogen bonds
76
What type of bond forms between the oxygen atom of one water molecule and the hydrogen atom of another water molecule?
Hydrogen bond
77
What is the result when electrons are shared equally between atoms in a molecule?
Nonpolar molecule
78
Which bond type involves the complete transfer of electrons from one atom to another?
Ionic bond
79
What is the term for an atom's outermost energy level that contains the chemically reactive electrons?
Valence shell
80
Electronegativity
The ability of an atom to attract electrons strongly.
81
Electropositive
Atoms with low electron-attracting ability, usually losing their valence electrons to other atoms.
82
What is a polar molecule?
A molecule with unequal sharing of electrons, resulting in a slight charge difference across the molecule.
83
What is a nonpolar molecule?
A molecule with equal sharing of electrons, resulting in no charge difference across the molecule.
84
What is an example of an ionic bond?
The formation of sodium chloride (NaCl) from sodium and chlorine atoms.
85
What is an example of a covalent bond?
The formation of a methane molecule (CH4) from carbon and hydrogen atoms.
86
What is an example of a hydrogen bond?
The attraction between the oxygen atom of one water molecule and the hydrogen atom of another water molecule.
87
What type of reaction involves the formation of a larger, more complex molecule from smaller molecules?
Synthesis reaction
88
What type of reaction involves breaking down a molecule into smaller molecules or constituent atoms?
Decomposition reaction
89
What type of reaction involves both synthesis and decomposition, where parts of the reactant molecules change partners?
Exchange reaction
90
What is another name for exchange reactions?
Displacement reactions
91
What type of reaction is characterized by the transfer of electrons between reactants?
Oxidation-reduction reaction
92
In a redox reaction, what is the reactant called that loses electrons?
Electron donor
93
In a redox reaction, what is the reactant called that gains electrons?
Electron acceptor
94
What is the main reason why many chemical reactions in the body are irreversible?
Energy released in the reaction is used up and products are removed from the reaction site
95
Which factor does NOT affect the rate of chemical reactions?
Color of reactants
96
What are biological catalysts called?
Enzymes
97
What happens to the reactant losing electrons in an oxidation-reduction reaction?
It is oxidized
98
What factor increases the rate of chemical reactions by increasing the kinetic energy of particles?
Higher temperatures
99
Oxidation
The process where a reactant loses electrons in a chemical reaction
100
Reduction
The process where a reactant gains electrons in a chemical reaction
101
What is the study of the chemical composition and reactions of living matter called?
Biochemistry
102
What type of compounds contain carbon and are made by living things?
Organic compounds
103
Which of the following is NOT considered an organic compound?
Water
104
Which of the following is generally defined as lacking carbon?
Inorganic compounds
105
Which of the following compounds contains carbon but is considered inorganic?
Carbon dioxide
106
What are the two major classes of chemicals in the body?
Organic and inorganic compounds.
107
Inorganic compounds
Compounds that generally lack carbon, including water, salts, and many acids and bases.
108
Why are carbon dioxide and carbon monoxide considered exceptions among inorganic compounds?
Because they contain carbon but are still classified as inorganic compounds.
109
Are organic or inorganic compounds more essential for life?
Both are equally essential for life.
110
What happens when water evaporates from the skin during sweating?
Large amounts of heat are removed from the body, providing efficient cooling.
111
Hydration layers
Layers of water molecules that form around large charged molecules, shielding them from other charged substances.
112
What role does water play in the body's transport system?
Water acts as a solvent, dissolving nutrients, gases, and wastes for transport.
113
How many covalent bonds can a carbon atom form?
Four
114
Which type of biological molecule is typically formed by dehydration synthesis?
Polymers
115
What are the small, reactive parts of organic molecules called?
Functional groups
116
Which element is uniquely suited to form long chainlike molecules and ring structures in biological systems?
Carbon
117
What is released each time a monomer is added to a growing polymer chain during dehydration synthesis?
A water molecule
118
What is the result of adding a water molecule to each bond during hydrolysis?
Breaking the bonds and releasing monomers
119
Which element is central to organic molecules due to its ability to form four covalent bonds?
Carbon
120
What type of molecules are carbohydrates, lipids, proteins, and nucleic acids?
Organic molecules
121
Monomer
A small molecule that can join with others to form a polymer.
122
Polymer
A large molecule made up of many similar or identical monomers linked together.
123
What elements do carbohydrates contain?
Carbon, hydrogen, and oxygen
124
What is the general formula for a monosaccharide?
(CH2O)n
125
Which of the following is a hexose sugar?
Glucose
126
What is the molecular formula for glucose?
C6H12O6
127
Which of the following is a disaccharide?
Sucrose
128
What is the primary function of carbohydrates in the body?
To provide a ready, easily used source of cellular fuel
129
What is glycogen?
A polysaccharide consisting of a polymer of glucose molecules
130
Where is glycogen primarily stored in the body?
Skeletal muscle and liver cells
131
What process breaks down disaccharides into monosaccharides?
Hydrolysis
132
Which polysaccharide is the storage carbohydrate in plants?
Starch
133
What type of carbohydrate is glucose classified as?
Monosaccharide
134
What is the difference between a monosaccharide and a disaccharide?
A monosaccharide is a single sugar molecule, while a disaccharide is composed of two monosaccharides joined together.
135
What are the two main polysaccharides important to the body?
Starch and glycogen
136
What are the building blocks of triglycerides?
Fatty acids and glycerol
137
Which type of lipid is the major form of stored energy in the body?
Triglycerides
138
What is the primary function of phospholipids in the body?
Chief components of cell membranes
139
What is the function of cholesterol in the body?
Component of cell membranes and starting molecule for synthesis of all body steroids
140
Which type of lipid is involved in regulating blood pressure and promoting inflammation?
Eicosanoids
141
What is the role of bile salts in the digestive tract?
Help with fat digestion and absorption
142
What makes phospholipids ideally suited for building cellular membranes?
They have both hydrophilic and hydrophobic ends
143
What type of lipid is Vitamin D classified as?
Steroid
144
Which type of lipid is known for being a powerful vasoconstrictor?
Thromboxanes
145
Which lipid type includes estrogens and testosterone?
Sex hormones
146
What is the primary function of triglycerides in the body?
They provide stored energy and insulate body organs.
147
Which type of lipid is formed from interlocking hydrocarbon rings?
Steroids
148
What are the two types of fatty acids based on the presence of double bonds?
Saturated and unsaturated fatty acids
149
Which vitamins are fat-soluble?
Vitamins A, D, E, and K
150
Where is DNA typically found in the cell?
Nucleus
151
Which sugar is found in RNA?
Ribose
152
Which base is found in RNA but not in DNA?
Uracil
153
What is the structure of DNA?
Double strand coiled into a double helix
154
What are the building blocks of nucleic acids?
Nucleotides
155
Which of the following bases pair together in DNA?
Adenine and Thymine
156
What is the major function of RNA?
Carries out the genetic instructions for protein synthesis
157
What is the sugar found in DNA?
Deoxyribose
158
What type of bond holds the two strands of DNA together?
Hydrogen bonds
159
What protects cells from excessive energy release during ATP hydrolysis?
The amount of energy released corresponds closely to that needed to drive most biochemical reactions
160
What happens to ADP when it loses its terminal phosphate group?
It becomes adenosine monophosphate (AMP).
161
What type of radiation causes atoms to ionize?
Ionizing radiation
162
Which cells are most affected by radiation sickness?
Rapidly dividing cells
163
What is acidosis?
A condition of acidity or low pH (below 7.35) of the blood; high hydrogen ion concentration.
164
What is alkalosis?
A condition of basicity or high pH (above 7.45) of the blood; low hydrogen ion concentration.
165
What are heavy metals?
Metals with toxic effects on the body, including arsenic, mercury, and lead. Iron is also toxic in high concentrations.
166
What is ionizing radiation?
Radiation that causes atoms to ionize; for example, gamma rays and X rays.
167
What is radiation sickness?
Disease resulting from exposure of the body to radioactivity; rapidly dividing cells are most affected—for example, blood-forming cells and the cells lining the digestive tract.
168
Chemical bonds
An energy relationship holding atoms together; involves the interaction of electrons.
169
Sol-gel transformations
Reversible change of a colloid from a fluid (sol) to a more solid (gel) state.
170
Inorganic compounds
Chemical substances that do not contain carbon, including water, salts, and many acids and bases.
171
Adenine (ad′ĕ-nēn)
One of the two major purines found in both RNA and DNA; also found in various free nucleotides of importance to the body, such as ATP.
172
Endergonic reaction
Chemical reaction that absorbs energy, e.g., an anabolic reaction.
173
Atomic number
The number of protons in an atom.
174
Acidosis (as″ĭ-do′sis)
State of abnormally high hydrogen ion concentration in the extracellular fluid.
175
Active sites
Region on the surface of a functional (globular) protein where it binds and interacts chemically with other molecules of complementary shape and charge.
176
Rule of eights (ok-tet′)
The tendency of atoms to interact in such a way that they have eight electrons in their valence shell.
177
Alpha (α)-helix
The most common type of secondary structure of the amino acid chain in proteins; resembles a coiled spring.
178
Energy
The capacity to do work; may be stored (potential energy) or in action (kinetic energy).
179
Mechanical energy
The energy directly involved in moving matter; e.g., in bicycle riding, the legs provide the mechanical energy that moves the pedals.
180
Nucleus (nu′kle-is)
(1) Control center of a cell; contains genetic material; (2) clusters of neuron cell bodies in the CNS; (3) center of an atom; contains protons and neutrons.
181
Covalent bond (ko-va′lent)
Chemical bond created by electron sharing between atoms.
182
Uracil (u′rah-sil)
A smaller, single-ring base (a pyrimidine) found in RNA.
183
Nonpolar molecules
Electrically symmetrical molecules.
184
Structural proteins
Consist of extended, strandlike polypeptide chains forming a strong, ropelike structure that is linear, insoluble in water, and very stable; e.g., collagen.
185
Decomposition reaction
Chemical reaction in which a molecule is broken down into smaller molecules or its constituent atoms.
186
Dipole (polar molecule)
Nonsymmetrical molecules that contain electrically unbalanced atoms.
187
Avogadro’s number (av ″ o-gad′rōz)
The number of molecules in one mole of any substance, 6.02 × 1023.
188
Hydrophilic (hi″dro-fil′ik)
Refers to molecules, or portions of molecules, that interact with water and charged particles.
189
Protein (pro′tēn)
Organic compound composed of carbon, oxygen, hydrogen, and nitrogen; types include enzymes, structural components; 10–30% of cell mass.
190
Macromolecules
Large, complex molecules containing from 100 to over 10,000 subunits.
191
Double helix
The secondary structure assumed by two strands of DNA, held together throughout their length by hydrogen bonds between bases on opposite strands.
192
Energy level
Regions of space that consecutively surround the nucleus of an atom; the atom’s electrons are most likely to be found in these regions.
193
Solutes (sol′yoot)
The substance that is dissolved in a solution.
194
Radioactivity
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.
195
Fatty acids
Linear chains of carbon and hydrogen atoms (hydrocarbon chains) with an organic acid group at one end. A constituent of fat.
196
Bicarbonate buffer system
Chemical system that helps maintain pH homeostasis of the blood. Also called carbonic acid–bicarbonate buffer system.
197
Kinetic energy (ki-net′ik)
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.
198
Molarity (mo-lar′ĭ-te)
A way to express the concentration of a solution; moles per liter of solution.
199
Coenzyme (ko-en′zīm)
Nonprotein substance associated with and activating an enzyme; typically a vitamin.
200
Displacement, reactions
Chemical reaction in which bonds are both made and broken; atoms are combined with different atoms.
201
Disaccharide (di-sak′ah-rīd, di-sak′ah-rid)
Literally, double sugar; e.g., sucrose, lactose.
202
Mass number
Sum of the number of protons and neutrons in the nucleus of an atom.
203
Ammonia (NH3)
Common waste product of protein breakdown in the body; a colorless volatile gas, very soluble in water and capable of acting as a weak base; a proton acceptor.
204
Valence shell (va′lens)
Outermost electron shell (energy level) of an atom that contains electrons.
205
Electrons
Negatively charged subatomic particle; orbits the atom’s nucleus.
206
Hydrogen ions
A hydrogen atom minus its electron and therefore carrying a positive charge (i.e., a proton).
207
Atomic symbol
The one- or two-letter symbol used to indicate an element; usually the first letter(s) of the element’s name.
208
Neutralization reaction
Displacement reaction in which mixing an acid and a base forms water and a salt.
209
Electron shells (energy levels)
Regions of space that consecutively surround the nucleus of an atom; the atom’s electrons are most likely to be found in these regions.
210
Glycogen (gli′ko-jin)
Main carbohydrate stored in animal cells; a polysaccharide.
211
Peptide bond (pep′tīd)
Bond joining the amine group of one amino acid to the acid carboxyl group of a second amino acid with the loss of a water molecule.
212
Hydrogen bonds
Weak bond in which a hydrogen atom forms a bridge between two electron-hungry atoms. An important intramolecular bond.
213
Cofactor
Metal ion or organic molecule that is required for enzyme activity.
214
Elements
One of a limited number of unique varieties of matter that composes substances of all kinds; e.g., carbon, hydrogen, oxygen.
215
Exergonic reactions
Chemical reaction that releases energy, e.g., a catabolic or oxidative reaction.
216
Synthesis
A chemical reaction in which larger, more complex atoms or molecules are formed from simpler ones.
217
Catalysts (kat′ah-list)
Substance that increases the rate of a chemical reaction without itself becoming chemically changed or part of the product.
218
Polymers
A substance of high molecular weight with long, chainlike molecules consisting of many similar (repeated) units.
219
Cytosine (si′to-sēn)
Nitrogen-containing base that is part of a nucleotide structure.
220
Chemical equilibrium
A state of apparent repose created by two reactions proceeding in opposite directions at equal speed.
221
Nucleic acids (nu-kle′ik)
Class of organic molecules that includes DNA and RNA.
222
Glycerol (glis′er-ol)
A modified simple sugar (a sugar alcohol); a building block of fats.
223
Octet rule (ok-tet′)
The tendency of atoms to interact in such a way that they have eight electrons in their valence shell.
224
Electrical energy
Energy formed by the movement of charged particles, e.g., across or along cell membranes.
225
Apoenzyme (ap′ō-en-zīm)
The protein portion of an enzyme.
226
Isotopes (i′so-tōps)
Different atomic forms of the same element, which vary only in the number of neutrons they contain; the heavier species tend to be radioactive.
227
Carbohydrates (kar″bo-hi′drāt)
Organic compound composed of carbon, hydrogen, and oxygen; includes starches, sugars, cellulose.
228
Amino acids (ah-me′no)
Organic compound containing nitrogen, carbon, hydrogen, and oxygen; building block of protein.
229
Activation energy
The amount of energy required to push a reactant to the level necessary for action.
230
Hydrophobic (hi″dro-fo′bik)
Refers to molecules, or portions of molecules, that interact only with nonpolar molecules.
231
Proton acceptors
A substance that takes up hydrogen ions in detectable amounts. Commonly referred to as a base.
232
Polysaccharides (pol″e-sak′ah-rīd)
Literally, many sugars, a polymer of linked monosaccharides; e.g., starch, glycogen.
233
Electromagnetic radiation
Emitted photons (wave packets) of energy, e.g., light, X ray, infrared.
234
Buffers
Chemical substance or system that minimizes changes in pH by releasing or binding hydrogen ions.
235
Cation (kat′i-on)
An ion with a positive charge.
236
Acids
A substance that releases hydrogen ions when in solution (compare with Base); a proton donor.
237
Mole (mōl)
A mole of any element or compound is equal to its atomic weight or its molecular weight (sum of atomic weights) measured in grams.
238
Exchange
Chemical reaction in which bonds are both made and broken; atoms are combined with different atoms.
239
Ionic bond (ī-ah′nik)
Chemical bond formed by electron transfer between atoms.
240
Monosaccharides (mon″o-sak′ah-rīd)
Literally, one sugar; building block of carbohydrates; e.g., glucose.
241
Dehydration synthesis
Process by which a large molecule is synthesized by removing water and covalently bonding smaller molecules together.
242
Chemical reaction
Process in which molecules are formed, changed, or broken down.
243
Atomic weight
The average of the mass numbers of all the isotopes of an element.
244
Reactants
A substance that is an input to a chemical reaction.
245
Organic compounds
Any compound composed of atoms (some of which are carbon) held together by covalent (shared electron) bonds. Examples are proteins, fats, and carbohydrates.
246
Polypeptide (pol″e-pep′tīd)
A chain of amino acids.
247
Molecule
Particle consisting of two or more atoms joined together by chemical bonds.
248
Thymine (thi′mēn)
Single-ring base (a pyrimidine) in DNA.
249
Enzymes (en′zīm)
A protein that acts as a biological catalyst to speed up a chemical reaction.
250
Substrate
A reactant on which an enzyme acts to cause a chemical action to proceed.
251
Lipids (lĭ′pid)
Hydrophobic organic compound formed of carbon, hydrogen, and oxygen; examples are fats and cholesterol.
252
Compound
Substance composed of two or more different elements, the atoms of which are chemically united.
253
Neutrons (nu′tron)
Uncharged subatomic particle; found in the atomic nucleus.
254
Suspensions
Heterogeneous mixtures with large, often visible solutes that tend to settle out.
255
Electrolytes (e-lek′tro-līt)
Chemical substances, such as salts, acids, and bases, that ionize and dissociate in water and are capable of conducting an electrical current.
256
Complementary bases
Refers to how a given nitrogenous base of DNA or RNA bonds to another nitrogenous base. For example, adenine (A) is the complementary base of thymine (T). The result is base pairing.
257
Proton donors
A substance that releases hydrogen ions in detectable amounts; an acid.
258
Isomers (ī′so-mer)
One of two or more substances that has the same molecular formula but with its atoms arranged differently.
259
Combination, reaction
A chemical reaction in which larger, more complex atoms or molecules are formed from simpler ones.
260
Ribonucleic acid (RNA) (ri′bo-nu-kle′ik)
Nucleic acid that contains ribose and the bases A, G, C, and U. Carries out DNA’s instructions for protein synthesis.
261
Triglycerides (tri-glis′er-īdz)
Fats and oils composed of fatty acids and glycerol; are the body’s most concentrated source of energy fuel.
262
Colloids (kol′oid)
(1) A mixture in which the solute particles (usually proteins) do not settle out readily. (2) Substance in the thyroid gland containing thyroglobulin protein.
263
Polar molecules
Electrically asymmetric molecules.
264
Chemical energy
Energy stored in the bonds of chemical substances.
265
Atoms
Smallest particle of an elemental substance that exhibits the properties of that element; composed of protons, neutrons, and electrons.
266
Phospholipids (fos″fo-lip′id)
Modified lipid, contains phosphorus.
267
Radioisotopes (ra″de-o-i′so-tōp)
Isotope that exhibits radioactive behavior.
268
Anion (an′i-on)
An ion with a negative charge.
269
Adenosine triphosphate (ATP) (ah-den′o-sēn tri″fos′fāt)
Organic molecule that stores and releases chemical energy for use in body cells.
270
Steroids (stĕ′roidz)
A class of lipids derived from (and including) cholesterol; act as hormones and as constituents of phospholipid bilayer membranes.
271
Hydrolysis (hi″drah′lă-sis)
Process in which water is used to split a substance into smaller parts.
272
Potential energy
Stored or inactive energy.
273
PH units (pe-āch)
The measure of the relative acidity or alkalinity of a solution.
274
Hydroxyl ions (hi-drok′sil)
An ion liberated when a hydroxide (a common inorganic base) is dissolved in water.
275
Alkalosis (al″kah-lo′sis)
State of abnormally low hydrogen ion concentration in the extracellular fluid.
276
Guanine (gwah′nēn)
One of two major purines occurring in all nucleic acids.
277
Kinetic energy (ki-net′ik)
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.
