Chapter 2

Question 1

A molecule that releases a proton when dissolved in water; generates hygronium ions, thereby lowering pH.

Answer 1

Acid

Question 2

Small organic molecule containing both an amino group and a carboxyl group; serves as the building block of proteins.

Answer 2

Amino acid

Question 3

The smallest particle of an element that still retains distinctive chemical properties; consists of a positively charged nucleus surrounded by a cloud of negatively charged electrons.

Answer 3

Atom

Question 4

The mass of an atom expressed in daltons, the atomic mass unit that closely approximates the mass of a hydrogen atom.

Answer 4

Atomic mass

Question 5

Molecule that serves as the principal carrier of energy in cells; composed of adenine, ribose, and three phosphate groups.

Answer 5

ATP

Question 6

Molecule that accepts a proton when dissolved in water; used to refer to the nitrogen-containing purines or pyrimidines in DNA and RNA.

Answer 6

Base

Question 7

Mixture of weak acids and bases that maintains the pH solution by releasing and taking up protons.

Answer 7

Buffer

Question 8

An exchange of electrons that holds two atoms together.

Answer 8

Chemical bond

Question 9

Combination of atoms, or an amino group, with distinct chemical and physical properties that influences the behavior of the molecule in which it resides.

Answer 9

Chemical group

Question 10

Chemical reaction in which a covalent bond is formed between two molecules as water is expelled; used to build polymers.

Answer 10

Condensation reaction

Question 11

Precise, three-dimensional shape of a protein or other macromolecule based on the spatial location of its atoms in relation to one another.

Answer 11

Conformation

Question 12

Stable chemical link between two atoms produced by sharing one or more pairs of electrons.

Answer 12

Covalent bond

Question 13

Force that draws together oppositely charged atoms.

Answer 13

Electrostatic attraction

Question 14

Molecule that consists of a carboxylic acid attached to a long hydrocarbon chain.

Answer 14

Fatty acid

Question 15

A weak noncovalent interaction between a positively charged hydrogen atom in one molecule and a negatively charged atom.

Answer 15

Hydrogen bond

Question 16

Chemical reaction that involves cleavage of a covalent bond with the accompanying consumption of water.

Answer 16

Hydrolysis

Question 17

Molecule or part of a molecule that readily forms hydrogen bonds with water, allowing it to dissolve.

Answer 17

Hydrophillic

Question 18

Nonpolar, uncharged molecule or part of a molecule that forms few or no hydrogen bonds with water molecules and therefore do not dissolve.

Answer 18

Hydrophobic

Question 19

Not composed of carbon and hydrogen

Answer 19

Inorganic

Question 20

An atom carrying an electrical charge, either positive or negative.

Answer 20

Ion

Question 21

Interaction formed when one atom donates electrons to another, making both atoms become electrically charged.

Answer 21

Ionic bond

Question 22

Organic molecule that is insoluble in water but dissolves in nonpolar organic solvents.

Answer 22

Lipid

Question 23

Thin pair of closely juxtaposed sheet, composed mainly of phospholipid molecules, that forms the structural basis for all cell membranes.

Answer 23

Lipid bilayer

Question 24

Polymer built from covalently linked subunits; includes proteins, nucleic acids, and polysaccharides with a molecular mass greater than a few thousand daltons.

Answer 24

Macromolecule

Question 25

Sum of the atomic weights of the atoms in a molecule; as a ratio of molecular masses, it is a number without units.

Answer 25

Molecular weight

Question 26

Group of atoms joined together by covalent bonds.

Answer 26

Molecule

Question 27

Small molecule that can be linked to others of a similar type to form a larger molecule.

Answer 27

Monomer

Question 28

Does not involve the sharing of electrons; singly they are weak, but can sum together to produce strong interactions between molecules.

Answer 28

Noncovalent bond

Question 29

Basic building blocks of the nucleic acids, DNA and RNA.

Answer 29

Nucleotide

Question 30

Chemical compound that contains carbon and hydrogen.

Answer 30

Organic molecule

Question 31

Long molecule made by covalently linking multiple or similar subunits.

Answer 31

Polymer

Question 32

A monomer that forms part of a larger molecule.

Answer 32

Subunit

Question 33

Weak noncovalent interaction, due to fluctuation electrical charges, that comes into play between two atoms within a short distance of each other.

Answer 33

van der Waals attraction

Question 34

Molecule containing the functional group -CONH2.

Answer 34

Amide

Question 35

Molecule containing an amino group-NH2.

Answer 35

Amine

Question 36

Negatively charged ion.

Answer 36

Anion

Question 37

Positively charged ion.

Answer 37

Cation

Question 38

Chemical linkage formed when two atoms share four electrons.

Answer 38

Double bond

Question 39

Membrane lipid molecule that has a short carbohydrate chain attached to its hydrophillic head.

Answer 39

Glycolipid

Question 40

A double-ringed, nitrogen-containing compound found in DNA and RNA.

Answer 40

Purine

Question 41

A nitrogen-containing, six membered ring compound found in DNA and RNA.

Answer 41

Pyrimidine

Question 42

Any substance that is dissolved in a lipid.

Answer 42

Solute