Chapter 2 - Chemical Level Of Organization

Front 1

Hydrogen bond

Back 1

The attraction between a 8+ on the hydrogen atom of polar covalent bond and a 8- on an oxygen or nitrogen atom of another polar covalent bond Hydrogen bonds are too weak to create molecules, but they can chage molecular shapes or pull molecules together.

Front 2

Surface tension

Back 2

acts as a barrier that keeps small objects from entering the water.

Front 3

Solids

Back 3

maintain their volume and their shape at ordinary temperatures and pressures.

Front 4

Liquids

Back 4

have a constant volume but no fixed shape. The shape of a liquid is determined by the shape of its container.

Front 5

Gases

Back 5

has neither a constant volume nor a fixed shape. Gases cna be compressed or expanded;unlike liquids they will fill a container of any size.

Front 6

Molecular weight

Back 6

The sum of the atomic weights of all the atoms in a molecule

Front 7

Synthesis

Back 7

is the opposite of decomposition. A synthesis reaction assembles smaller molecules into larger molecules. manufacture anabolism

Front 8

Dehydration synthesis/condensation

Back 8

is the formation of a complex molecule by the removal of water

Front 9

anabolism

Back 9

The synthesis of new molecules within the body's cells and tissues

Front 10

Exchange reaction

Back 10

parts of the reacting molecules are shuffled around to produce new products

Front 11

Reversible Reactions

Back 11

Chemical reactions are reversible, so if A + B = AB

Front 12

activation energy

Back 12

amount of energy required to start a reaction

Front 13

Enzymes

Back 13

Proteins promote chemical reactions by lowering the activation energy requirements.

Front 14

Chemical reaction

Back 14

form between atoms or existing bonds between atoms are broken

Front 15

reactants

Back 15

changes occur as atoms in the reacting substances

Front 16

products

Back 16

rearranged to form different substances

Front 17

metabolism

Back 17

all of the reactions under way in the cells and tissues of the body at any given moment

Front 18

Work

Back 18

the movement of an object or a change in the physical structure of matter

Front 19

Energy

Back 19

is the capacity to perform work;movement or physical change cannot occur unless energy is provided

Front 20

Kinetic energy

Back 20

is the energy of motion-energy that is doing work

Front 21

Potential energy

Back 21

is stored energy- energy that has the potential to do work

Front 22

Decomposition

Back 22

is a reaction that breaks a molecule into smaller fragments

Front 23

hydrolysis

Back 23

one of the bonds in a complex molecule is broken, and the components of a water molecule are added to the resulting fragments

Front 24

catabolism

Back 24

Collectively, the decomposition reactions of complex molecules within the body's cells and tissues

Front 25

catalysts

Back 25

Enzymes belong to a class of substance

Front 26

Exergonic

Back 26

Reactions that release energy

Front 27

Endergonic

Back 27

more energy is required to begin the reaction than is released as it proceeds, the reaction as a whole will absorb energy

Front 28

Nutrients

Back 28

essential elements and molecules normally obtained from the diet

Front 29

Metabolites

Back 29

molecules that can be synthesized or broken down by chemical reactions inside our bodies

Front 30

Inorganic compounds

Back 30

generally do not contain carbon and hydrogen atoms as their primary structural ingredients

Front 31

Organic compounds

Back 31

carbon and hydrogen always form the basis

Front 32

Proteins

Back 32

the most abundant organic components of the human body and in many ways the most important

Front 33

Support- Structural proteins

Back 33

create a three-dimensional framework for the body, providing strength,organization, and support for cells, tissues and organs

Front 34

Movement- Contractile proteins

Back 34

responsible for muscular contraction;related proteins are responsible for the movement of individual cells

Front 35

Transport

Back 35

insoluble lipids, respiratory gases, special minerals such as iron, and several hormones cannot be transported in the blood

Front 36

Buffering

Back 36

proteins provide a considerable buffering action and thereby help prevent dangerous changes in pH in cells and tissues

Front 37

Metabolic Regulation

Back 37

Enzymes accelerate chemical reactions in cells

Front 38

Coordination and Control

Back 38

protein hormones can influence the metabolic activities of every cell in the body or affect the functgion of specific organs or organ systems

Front 39

Defense

Back 39

The tough, waterproof proteins of the skin, hair, and nails protect the body from environmental hazards.

Front 40

amino acids

Back 40

Proteins consist of long chains of organic molecules

Front 41

Peptide bond

Back 41

A covalent bond between the carboxylic acid group of one amino acid and the amino group of another

Front 42

Peptides

Back 42

Molecules consisting of amino acids held together by peptide bonds.

Front 43

Polypeptides

Back 43

Tripeptides and larger peptide chains

Front 44

Primary structure

Back 44

is the sequence of amino acids along the length of a single polypeptide

Front 45

Secondary structure

Back 45

results from bonds between atoms at different parts fo the polypeptide chain.

Front 46

Tertiary structure

Back 46

is the complex coiling and folding that gives a protein its final three-dimensional shape

Front 47

Quaternary structure

Back 47

is the interaction between individual polypeptide chains to form a protein complex

Front 48

Fibrous proteins

Back 48

form extended sheets or strands

Front 49

Globular proteins

Back 49

are compact, generally rounded, and readily enter an aqueoud solution

Front 50

Substrates

Back 50

Reactants in enzymatic reactons

Front 51

Active site

Back 51

A groove or pocket into which one or more substrates nestle.

Front 52

specificity

Back 52

Each enzyme catalyzes only one type of reaction

Front 53

isozymes

Back 53

Different tissues typically contain enzymes that differ slightly in structure, but catalyze the same reaction

Front 54

Saturated

Back 54

Enzyme that has reached its saturation limit

Front 55

Cofactor

Back 55

is an ion or a molecule that must bind to the enzyme before substrates can also bind

Front 56

coenzymes

Back 56

nonprotein organic molecules that function as cofactors

Front 57

denaturation

Back 57

change in tertiary or quaternary structure that makes it nonfunctional.

Front 58

glycoproteins/proteoglycans

Back 58

combinations of protein and carbohydrate molecules

Front 59

mucus

Back 59

Coats the surfacesw of the respiratory adn digestive tracts, providing lubrication

Front 60

Nucleic acids

Back 60

large organic molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus

Front 61

deoxyribonucleic acid

Back 61

two classes of nucleic acid molecules

Front 62

chemistry

Back 62

the science that deals with the structure of matter

Front 63

atoms

Back 63

smallest stable units of matter

Front 64

subatomic particles

Back 64

atoms are composed of subatomic particles and only 3 are important, the chemical propertiesof matter: protons, neutrons, and electrons

Front 65

protons

Back 65

(p+) bear a positive electrical charge

Front 66

neutrons

Back 66

(n or n') are electrically neutral, or uncharged.

Front 67

electrons

Back 67

(e-) are much lighter than protons-only 1/1836 as massive-and bear a negative electrical charge.

Front 68

atomic number

Back 68

the number of protons in an atom

Front 69

hydrogen (H)

Back 69

the simplest atom, with an atomic number of 1. Contains 1 proton and 1 electron

Front 70

electron cloud

Back 70

electrons orbit the nucleus at high speed forming a spherical electron cloud.

Front 71

electron shell

Back 71

electron tends to remain in its electron shell because the negatively charged electron is attracted to the positively charged proton.

Front 72

electrical force

Back 72

the attraction between opposite electrical charges.

Front 73

nanometers (nm)

Back 73

atoms are so small that atomic measurements are most conveniently reported in nm

Front 74

elements

Back 74

all the atoms with the same atomic number (2)

Front 75

trace elements

Back 75

human body contains atoms of another 13 elements-that are present in very small amounts

Front 76

isotopes

Back 76

atoms of the same element whose nuclei contain the same number of protons, but different numbers of neutrons

Front 77

mass number

Back 77

the total number of protons plus neutrons in the nucleus-used to designate isotopes

Front 78

deuterium

Back 78

hydrogen-2 one proton, one electron and one neutron

Front 79

tritium

Back 79

hydrogen-3 one proton, one elecron, and 2 neutrons

Front 80

radioisotopes

Back 80

isotopes spontaneously emit subatomic particles or radiation in measurable amounts

Front 81

radioactive decay

Back 81

emission process of radioisotopes

Front 82

half-life

Back 82

the time required for half of a given amount of the isotope to decay

Front 83

oxygen atom

Back 83

has an atomic number of 8, contains 8 protons and 8 neutrons. mass number of this isotope is 16

Front 84

atomic weight

Back 84

the actual mass of an atom

Front 85

dalton

Back 85

unit used to express atomic weight

Front 86

mole

Back 86

a quantity with a weight in grams equal to that element's atomic weight

Front 87

energy levels

Back 87

within the electron cloud, elecrons occupy an orderly series

Front 88

lithium

Back 88

an atom that has three electrons

Front 89

reactive

Back 89

elements with unfilled outermost energy levels, such as hydrogen and lithium

Front 90

chemical bonds

Back 90

holds the participating atoms together once the reaction has ended

Front 91

molecule

Back 91

any chemical structure consisting of atoms held together by covalent bonds

Front 92

compound

Back 92

any chemical substance made up of atoms fo two or more elements, regardless of the type of bond joining them, not all molecules are compounds

Front 93

Ions

Back 93

atoms or molecules that carry an electric charge, either positive or negative

Front 94

cations

Back 94

ions with a positive charge

Front 95

anions

Back 95

ions with a negative charge

Front 96

Ionic bonds

Back 96

chemical bonds created by the elecrical attraction between anions and cations

Front 97

sodium ion

Back 97

with a charge of +1

Front 98

chloride ion

Back 98

with a charge of -1

Front 99

sodium chloride

Back 99

the combination of oppositely charged ions forms an ionic compound--this case sodium chloride

Front 100

covalent bonds

Back 100

a chemical bond between atoms that involves the sharing of electrons

Front 101

single covalent bond

Back 101

sharing of one pair of electrons

Front 102

double covalent bond

Back 102

sharing two pairs of electrons

Front 103

carbon dioxide

Back 103

a compound produced by the decarboxylation reactions of aerobic metabolism

Front 104

nonpolar covalent bonds

Back 104

equal sharing of electrons- between two atoms of the same type-bonds are very common

Front 105

polar covalent bond

Back 105

unequal sharing of electrons

Front 106

hydrogen bond

Back 106

weak-the attraction between a___ on the hydrogen atom of a polar covalent bond and a ____ on an oxygen or nitrogen atom of another polar covalent bond

Front 107

surface tension

Back 107

acts as a barrier that keeps small objects from entering the water

Front 108

solids

Back 108

maintain their volume and their shape at ordinary temps and pressures.

Front 109

liquids

Back 109

have a constant volume, but no fixed shape of its container

Front 110

gas

Back 110

has neither a constant volume nor a fixed shape- gases can be compressed or expanded

Front 111

molecular weight

Back 111

the sum of the atomic weights of its component atoms

Front 112

solution

Back 112

individual molecules become distributed within the water

Front 113

solvent

Back 113

the medium in which other atoms, ions, or molecules are dispersed

Front 114

solutes

Back 114

dispersed substances

Front 115

electrolytes

Back 115

soluble inorganic molecules whose ions will conduct an electrical current in solution

Front 116

hydrophilic

Back 116

freely associating with water; readily entering into solution

Front 117

hydrophobic

Back 117

incapable of freely associating with water molecules; insoluble

Front 118

colloid

Back 118

a soluion containing dispersed proteins or other large molecules

Front 119

pH

Back 119

the negative exponent of the hydrogen ion concentration, expressed in moles per litre

Front 120

neutral

Back 120

a solution with a pH 7, contains equal number of hydrogen and hydroxide ions

Front 121

acidic

Back 121

a solution with a pH below 7, contains more hydrogen ions than hydroxide ions

Front 122

basic

Back 122

a pH above 7, has more hydroxide ions than hydrogen ions

Front 123

acid

Back 123

any solute that dissociates in solution and releases hydrogen ions, thereby lowering the pH

Front 124

base

Back 124

a solute that removes hydrogen ions from a solution and thereby acts as a proton accceptor

Front 125

salt

Back 125

an ionic compound consisting of any cation except a hydrogen ion and any anion except a hydroxide ion

Front 126

buffers

Back 126

compounds that stabilize the pH of a solution by removing or replacing hydrogen ions

Front 127

carbohydrate

Back 127

an organic molecule that contains carbon, hydrogen, and oxygen in a ratio near 1:2:1

Front 128

monosaccharide (simple sugar)

Back 128

a carbohydrate containing from 3 to 7 carbon atoms

Front 129

glucose

Back 129

most important metabolic "fuel" in the body

Front 130

isomers

Back 130

molecules - same types and numbers of atoms--but different structures

Front 131

disaccharide

Back 131

complex molecules composed of 2 monocaccharide building blocks joined together

Front 132

carbohydrate

Back 132

an organic molecule that contains carbon, hydrogen, and oxygen in a ratio near 1:2:1

Front 133

monosaccharide (simple sugar)

Back 133

a carbohydrate containing from 3 to 7 carbon atoms

Front 134

glucose

Back 134

most important metabolic "fuel" in the body

Front 135

isomers

Back 135

molecules - same types and numbers of atoms--but different structures

Front 136

disaccharide

Back 136

a compound formed by the joining of 2 smple sugars by dehydration synthesis

Front 137

polysaccharides

Back 137

a complex sugar, such as glycogen or a starch

Front 138

glycogen

Back 138

a polysaccharide that is an important energy reserve; a polymer consisting of a long chain of glucose molecules

Front 139

lipids

Back 139

an organic compound containing carbons, hydrogens, and oxygens in a ratio that does not approximate 1:2:1; includes fats, oils, and waxes

Front 140

fatty acids

Back 140

hydrocarbon chains that end in a carboxylic acid group

Front 141

eicosanoids

Back 141

lipids derived from a fatty acid that must be absorbed in the diet because it cannot be synthesized by the body

Front 142

polysaccharides

Back 142

a complex sugar, such as glycogen or a starch

Front 143

glycogen

Back 143

a polysaccharide that is an important energy reserve; a polymer consisting of a long chain of glucose molecules

Front 144

lipids

Back 144

an organic compound containing carbons, hydrogens, and oxygens in a ratio that does not approximate 1:2:1; includes fats, oils, and waxes

Front 145

fatty acids

Back 145

hydrocarbon chains that end in a carboxylic acid group

Front 146

eicosanoids

Back 146

lipids derived from a fatty acid that must be absorbed in the diet because it cannot be synthesized by the body

Front 147

prostaglandins

Back 147

a fatty acid secreted by one cell that alters the metabolic activities or sensitivities of adjacent cells; also called local hormone

Front 148

glycerol

Back 148

a compound

Front 149

glycerides

Back 149

lipids composed of glycerol bound to fatty acids

Front 150

monoglyceride

Back 150

a lipid consisting of a single fatty acid bound to a molecule of glycerol

Front 151

diglyceride

Back 151

glycerol + two fatty acids

Front 152

triglyceride

Back 152

glycerol + three fatty acids

Front 153

steroids

Back 153

large lipid molecules that share a distinctive carbon framework
a ring-shaped lipid structurally related to cholesterol

Front 154

cholesterol

Back 154

a steroid component of cell membranes and a substrate for the synthesis of steroid hormones and bile salts

Front 155

phospholipid

Back 155

an important membrane lipid whose structure includes both hydrophilic and hydrophobic regions

Front 156

glycolipids

Back 156

compounds created by the combination of carbohydrate and lipid components

Front 157

metabolic turnover

Back 157

The continuous removal and replacement of cellular organic molecules,allows cells to change and to adapt to chnges in their environment