Biology 108 Chapter 2

Front 1

Acid

Back 1

Molecules tending to raise the hydrogen ion concentration in a solution and to lower its pH numerically.

Front 2

Adenine (A)

Back 2

One of four nitrogen bases in nucleotides composing the structure of DNA and RNA.

Front 3

ADP (adenosine diphosphate)

Back 3

Nucleotide with two phosphate groups that can accept another phosphate group and become ATP.

Front 4

Amino Acid

Back 4

Organic molecule having an amino group and an acid group, which covalently bonds to produce peptide molecules.

Front 5

Atom

Back 5

Smallest particle of an element that displays the properties of the element.

Front 6

Atomic Mass

Back 6

Mass of an atom equal to the number of protons plus the number of neutrons with the nucleus.

Front 7

Atomic Number

Back 7

Number of protons within the nucleus of an atom.

Front 8

ATP (adenosine triphosphate)

Back 8

Nucleotide with three phosphate groups. The breakdown of ATP into ADP + P makes energy available for energy-requiring processes in cells.

Front 9

Base

Back 9

Molecules tending to lower the hydrogen ion concentration in a solution and raise the pH numerically.

Front 10

Buffer

Back 10

Substance or group of substances that tend to resist pH changes of a solution, thus stabilizing its relative acidity and basicity.

Front 11

Calorie

Back 11

Amount of heat energy required to raise the temperature of 1 g of water 1 degree C.

Front 12

Carbohydrate

Back 12

Class of organic compounds that includes monosaccharides, disaccharides, and polysaccharides.

Front 13

Cellulose

Back 13

Polysaccharide that is the major complex carbohydrate in plant cell walls.

Front 14

Complementary Paired Bases

Back 14

Hydrogen bonding between particular bases; in DNA thymine (T) paris with Adenine (A), and guanine (G) pairs with cytosine (C); in RNA, uracil (U) paris with A, and G pairs with C.

Front 15

Compound

Back 15

Substance having two or more different elements united chemically in a fixed ration.

Front 16

Covalent Bond

Back 16

Chemical bond in which atoms share one pair of electrons.

Front 17

Cytosine (C)

Back 17

One of four nitrogen bases in nucleotides composing the structure of DNA and RNA.

Front 18

Dehydration Reaction

Back 18

Chemical reaction resulting in a covalent bond with the accompanying loss of a water molecule.

Front 19

Denaturation

Back 19

Loss of normal shape by an enzyme so that it no longer functions; caused by a less than potimal pH or temperature.

Front 20

Disaccharide

Back 20

Sugar that contains two units of a monosaccharide (e.g., maltose).

Front 21

DNA (deoxyribonucleic acid)

Back 21

Nucleic acid polymer produced from covalent bonding of nucleotide monomers that contain the sugar deoxyribose; the genetic material of nearly all organisms.

Front 22

Electron

Back 22

Negative subatomic particle, moving about in an energy level around the nucleus of an atom.

Front 23

Element

Back 23

Substance that cannot be broken down into substances with different properties; composed of only one type of atom.

Front 24

Emulsification

Back 24

Breaking up of fat globules into smaller droplets by the action of bile salts or any other emulsifier.

Front 25

Fat

Back 25

Organic molecule that contains glycerol and fatty acids; found in adipose tissue.

Front 26

Fatty Acid

Back 26

Molecule that contains a hydrocarbon chain and ends with an acid group.

Front 27

Glucose

Back 27

Six-carbon sugar that organisms degrade as a source of energy during cellular respiration.

Front 28

Glycogen

Back 28

Storage polysaccharide composed of glucose molecules joined in a linear fashion but having numerous branches.

Front 29

Guanine (G)

Back 29

One of four nitrogen-containing bases in nucleotides composing the structure of DNA and RNA; pairs with cytosine.

Front 30

Hemoglobin

Back 30

Iron-containing pigment in red blood cells that combines with and transports oxygen.

Front 31

Hexose

Back 31

Six-carbon sugar.

Front 32

Hydrogen Bond

Back 32

Weak bond that arises between a slightly positive hydrogen atom of one molecule and slightly negative atom of another, or between parts of the same molecule.

Front 33

Hydrolysis Reaction

Back 33

Splitting of a compound by the addition of water, with the H+ being incorporated in one fragment and the OH- in the other.

Front 34

Hydrophilic

Back 34

Type of molecule that interacts with water by dissolving in water and/or forming hydrogen bonds with water molecules.

Front 35

Hydrophobic

Back 35

Type of molecule that does not interact with water because it is nonpolar.

Front 36

Ion

Back 36

Charged particle that carries a negative or positive charge.

Front 37

Ionic Bond

Back 37

Chemical bond in which ions are attracted to one another by opposite charges.

Front 38

Isotope

Back 38

One of two or more with the same atomic number but a different atomic mass due to the number of neutrons.

Front 39

Lipid

Back 39

Class of organic compounds that tends to be soluble only in nonpolar solvents, such as alcohol; includes fats and oils.

Front 40

Macromolecule

Back 40

Extremely large biological molecule; refers specifically to proteins, nucleic acids, polysaccharides, lipids, and complexes of these.

Front 41

Mass

Back 41

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

Front 42

Mass Number

Back 42

The number of nucleons (protons and neutrons) in the nucleus of an atom.

Front 43

Matter

Back 43

Anything that takes up space and has mass.

Front 44

Mole

Back 44

A unit of scientific measurement for atoms, ions, and molecules.

Front 45

Molecule

Back 45

Union of two or more atoms of the same element; also, the smallest part of a compound that retains the properties of the compound.

Front 46

Monosaccharide

Back 46

Simple sugar; a carbohydrate that cannot be decomposed by hydrolysis (e.g., glucose).

Front 47

Nucleus

Back 47

Membrane-bounded organelle that contains chromosomes and controls the structure and function of the cell.

Front 48

Neutron

Back 48

Neutral subatomic particle, located in the nucleus and having a weight of approximately one atomic mass unit.

Front 49

Nucleotide

Back 49

Monomer of DNA and RNA consisting of a 5-carbon sugar bonded to a nitrogen-containing base and a phosphate group.

Front 50

Oil

Back 50

Substance, usually of plant origin and liquid at room temperature, formed when a glycerol molecule reacts with three fatty acid molecules.

Front 51

Orbital

Back 51

Pathways in which electrons travel around the nucleus of an atom.

Front 52

Organic

Back 52

Molecule that always contains carbon and hydrogen, and often contains oxygen as well; organic molecules are associated with living things.

Front 53

Organic Molecule

Back 53

Type of molecule that contains carbon and hydrogen - and often contains oxygen also.

Front 54

Pentose

Back 54

Five-carbon sugar. Deoxyribose is the pentose sugar found in DNA; ribose is a pentose sugar found in RNA

Front 55

Peptide Bond

Back 55

Type of covalent bond that joins two amino acids.

Front 56

Phospholipid

Back 56

Molecule that forms the bilayer of the cell's membranes; has a polar, hydrophilic head bonded to two nonpolar, hydrophobic tails.

Front 57

pH scale

Back 57

Measurement scale for hydrogen ion concentration.

Front 58

Polar

Back 58

Combination of atoms in which the electrical charge is not distributed symmetrically.

Front 59

Polypeptide

Back 59

Polymer of many amino acids linked by peptide bonds.

Front 60

Polysaccharide

Back 60

Polymer made from sugar monomers; the polysaccharides starch and glycogen are polymers of glucose monomers.

Front 61

Protein

Back 61

Molecule consisting of one or more polypeptides.

Front 62

Proton

Back 62

Positive subatomic particle, located in the nucleus and having a weight of approximately one atomic mass unit.

Front 63

Radioisotope

Back 63

Unstable form of an atom that spontaneously emits radiation in the form of radioactive particles or radiant energy.

Front 64

RNA (ribonucleic acid)

Back 64

Nucleic acid produced from covalent bonding of nucleotide monomers that contain the sugar ribose; occurs i three forms: messenger RNA, ribosomal RNA, and transfer RNA.

Front 65

Saturated Fatty Acid

Back 65

Fatty-acid molecule that lacks double bonds between the atoms of its carbon chain.

Front 66

Starch

Back 66

Storage polysaccharide found in plants that is composed of glucose molecules joined in a linear fashion with few side chains.

Front 67

Steroid

Back 67

Type of lipid molecule having a complex of four carbon rings; examples are cholesterol, progesterone, and testosterone.

Front 68

Thymine (T)

Back 68

One of four nitrogen-containing bases in nucleotides composing the structure of DNA; paris with adenine.

Front 69

Tracer

Back 69

Substance having an attached radioisotope that allows a researcher to track its whereabouts in a biological system.

Front 70

Trans Fat

Back 70

Fats, which occur naturally in meat and dairy products of ruminants, that are also industrially created through partial hydrogenation of plant oils and animal fats.

Front 71

Triglyceride

Back 71

Neutral fat composed of glycerol and three fatty acids.

Front 72

Unsaturated Fatty Acid

Back 72

Fatty-acid molecule that has one or more double bonds between the atoms of its carbon chain.

Front 73

Uracil (U)

Back 73

The base in RNA that replaces thymine found in DNA; pairs with adenine.