Chapter 2 - The Chemistry of Life

Question 1

Atom

Answer 1

The basic unit of matter

Question 2

Nucleus

Answer 2

The center of an atom, which contains the protons and neutrons

Question 3

Electron

Answer 3

Negatively charged atom: constantly moving around the nucleus

Question 4

Element

Answer 4

Pure substance that consists entirely of one type of atom

Question 5

Isotope

Answer 5

One of several forms of a single element, which contains the same number of protons but different numbers of neutrons

Question 6

Compound

Answer 6

Substance formed by the chemical combination of two or more elements in definite proportions

Question 7

Ionic bond

Answer 7

Chemical bond formed when one or more electrons are transferred from one atom to another

Question 8

Ion

Answer 8

Atom that has a positive or negative charge

Question 9

Covalent bond

Answer 9

Type of bonds between atoms in which their electrons are shared

Question 10

Molecule

Answer 10

Smallest unit of most compounds that displays all of the properties of that compound

Question 11

Van der Waals forces

Answer 11

Weak attraction that develops between oppositely charged regions of nearby molecules

Question 12

Hydrogen bond

Answer 12

Weak attraction between a slightly positive hydrogen atom and another atom that is slightly negative

Question 13

Cohesion

Answer 13

Attraction between molecules of the same substance

Question 14

Adhesion

Answer 14

Force of attraction between different kinds of molecules

Question 15

Heat capacity

Answer 15

The amount of energy needed to raise the temperature of a substance

Question 16

Mixture

Answer 16

Material composed of two or more elements or compounds that are physically mixed together but not chemically combined

Question 17

Solution

Answer 17

Type of mixture in which all the components are evenly distributed

Question 18

Solute

Answer 18

Substance that is dissolved in a solution

Question 19

Solvent

Answer 19

Dissolving substance in a solution

Question 20

Suspension

Answer 20

Mixture of water and undissolved material

Question 21

pH scale

Answer 21

Scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution
**Lower pH = more Hydrogen ions present in a solution

Question 22

Acid

Answer 22

A compound that forms hydrogen ions (H+) in a solution; a solution with a pH of less than 7

Question 23

Base

Answer 23

A compound that produces hydroxide ions (OH-) in a solution; a solution with a pH of more than 7

Question 24

Buffer

Answer 24

A solution that prevents sharp, sudden changes in pH

Question 25

Monomer

Answer 25

Small chemical unit that makes up a polymer

Question 26

Polymer

Answer 26

Molecules composed of many monomers; makes up macromolecules

Question 27

Biological molecules

Answer 27

Monosaccharides (simple sugars that make up polysaccharides); polysaccharides

Question 28

Carbohydrate

Answer 28

Compound made up of oxygen, hydrogen and carbon atoms; type of nutrient that is the major source of energy for the body

Question 29

Lipid

Answer 29

Macromolecule made of mostly hydrogen and carbon atoms; includes fats, oils and waxes

Question 30

Fatty acids

Answer 30

Lipids that are formed by combining a glycerol molecule with a fatty acid **Fatty acids that are saturated can stack together and are usually solids at room temperature (butter). Fatty acids that are unsaturated don’t stack together well and are usually liquids at room temperature

Question 31

Nucleotide

Answer 31

Subunit of which nucleic acids are composed; made of 5-carbon sugar, a phosphate group, and a nitrogenous group

Question 32

Nucleic acid

Answer 32

Macromolecules containing hydrogen, oxygen, carbon, nitrogen and phosphorus

Question 33

Protein

Answer 33

Macromolecule that contains carbon, hydrogen, oxygen and nitrogen; needed by the body for growth and repair **Amino acids are the monomer units of proteins

Question 34

4 structures of a protein

Answer 34

Primary: The sequence of amino acids in the protein Secondary: Locally folded structures, like helices and sheet-like structures Tertiary: A fully folded polypeptide chain Quaternary: Multiple polypeptide chains come to form the active protein

Question 35

Polypeptide

Answer 35

A chain of amino acids joined by peptide bonds

Question 36

Amino acid

Answer 36

Compound with an amino group on one end and a carboxyl group on the other end, with a R-group in a central carbon

Question 37

Chemical reaction

Answer 37

Process that changes, or transforms, one set of chemicals into another set of chemicals **Either absorbs or releases energy

Question 38

Reactant

Answer 38

Chemicals or compounds that enter into a chemical reaction

Question 39

Product

Answer 39

Elements or compounds produced by a chemical reaction

Question 40

Activation energy

Answer 40

Energy that is needed to get a reaction started

Question 41

Catalyst

Answer 41

Substance that speeds up the rate of a chemical reaction, without getting used up in the process

Question 42

Enzyme

Answer 42

Protein catalyst that speeds up the rate of specific biological reactions **Help maintain homeostasis (operate at a set condition); bind to substrates

Question 43

Substrate

Answer 43

Reactant of an enzyme-catalyzed reaction