Chapter 2 Practice Test

Front 1

The smallest chemical units of matter of which no chemical change can alter their identity are:

Back 1

atoms

Front 2

The three subatomic particles that are stable constituents of atomic structure are:

Back 2

protons, neutrons, and electrons

Front 3

The protons in an atom are found only:

Back 3

in the nucleus

Front 4

The unequal sharing of electrons in a molecule of water is an example of:

Back 4

a polar covalent bond

Front 5

The attraction between cations and anions is important in:

Back 5

ionic bonds

Front 6

The symbol 2H means:

Back 6

two atoms of hydrogen

Front 7

From the following choices, select the one which diagrams a typical decomposition reaction:

Back 7

AB = A + B

Front 8

A + B <==> AB is an example of a __________ reaction.

Back 8

Blank

Front 9

AB + CD <==> AD + CB is an example of a __________ reaction.

Back 9

reversible, synthesis, and exchange

Front 10

The presence of an appropriate enzyme affects only the:

Back 10

rate of reaction

Front 11

Organic catalysts made by a living cell to promote a specific reaction are called:

Back 11

enzymes

Front 12

The major difference between inorganic and organic compounds is that inorganic compounds are usually:

Back 12

not structurally made from carbon and hydrogen

Front 13

The four major classes of organic compounds are:

Back 13

carbohydrates, lipids, proteins, and nucleic acids

Front 14

The ability of water to maintain a relatively constant temperature and then prevent rapid changes in body temperature is due to its:

Back 14

capacity to absorb and distribute heat

Front 15

To maintain homeostasis in the human body, the normal pH range of the blood must remain at:

Back 15

7.35 to 7.45

Front 16

An enzyme can catalyze a reaction by:

Back 16

binding to a substrate

Front 17

The ideal medium for the absorption and/or transport of inorganic or organic compounds is:

Back 17

water

Front 18

A solute that dissociates to release hydrogen ions and causes a decrease in pH is:

Back 18

an acid

Front 19

A solute that removes hydrogen ions from a solution is:

Back 19

a base

Front 20

A carbohydrate molecule is made up of:

Back 20

carbon, hydrogen, and oxygen

Front 21

Carbohydrates are most important to the body in that they serve as primary sources of:

Back 21

Energy

Front 22

The small molecules that form chains to build proteins are called:

Back 22

amino acids

Front 23

Special proteins that are involved in metabolic regulation are called:

Back 23

enzymes

Front 24

The three basic components of a single nucleotide of a nucleic acid are:

Back 24

sugar, phosphate group, and nitrogen base

Front 25

The most important high-energy compound found in the human body is:

Back 25

ATP

Front 26

The chemical properties of every element are determined by:

Back 26

the number and arrangement of electrons in the outer energy level

Front 27

Whether an atom will react with another atom will be determined primarily by:

Back 27

the number of electrons in the outermost energy level

Front 28

In the formation of nonpolar covalent bonds there is:

Back 28

equal sharing of protons and electrons

Front 29

The symbol 2H2O means that two identical molecules of water are each composed of:

Back 29

2 hydrogen atoms and 1 oxygen atom

Front 30

The reason water is particularly effective as a solvent is:

Back 30

polar molecules are formed due to the closeness of hydrogen atoms

Front 31

The action of a buffer to maintain pH with normal limits consists primarily of:

Back 31

removing or replacing hydrogen ions

Front 32

A salt may best be described as:

Back 32

an inorganic molecule created by the reaction of an acid and a base

Front 33

The chemical makeup of a lipid molecule is different from a carbohydrate in that the lipid molecule:

Back 33

contains much less oxygen than a carbohydrate having the same number of carbon atoms

Front 34

Lipid deposits are important as energy reserves because:

Back 34

lipids provide twice as much energy as carbohydrates

Front 35

Proteins differ from carbohydrates in that they:

Back 35

always contain nitrogen

Front 36

Isotopes of an element are:

Back 36

atoms whose nuclei contain different numbers of neutrons

Front 37

Compared with the other major organic compounds, nucleic acids are unique in that they:

Back 37

store and process information at the molecular level

Front 38

What happens to an enzyme that is subjected to extremely high temperatures?

Back 38

It becomes denatured.

Front 39

If an atom has an atomic number of 92 and its atomic weight is 238, how many protons does the atom have?

Back 39

92

Front 40

If the second energy level of an atom has one (1) electron, how many more does it need to fill it to its maximum capacity?

Back 40

7

Front 41

Which of the following statements about carbohydrates is NOT correct?

Back 41

All polysaccharides have a sweet taste and dissolve easily in water.

Front 42

Which type of lipid is a good energy source, provides insulation, and helps protect delicate organs?

Back 42

Triglycerides

Front 43

Which one of the following selections represents the pH of the weakest acid?

Back 43

6.7

Front 44

The type of bond that has the most important effects on the properties of water and the shapes of complex molecules is the:

Back 44

hydrogen bond

Front 45

If oxygen has an atomic weight of 16, what is the molecular weight of an oxygen molecule?

Back 45

32

Front 46

A molecule that is hydrophobic consists of

Back 46

fats and oils

Front 47

The dispersed substances in a solution are called:

Back 47

solutes

Front 48

Two simple sugars joined together form a disaccharide. The reaction involved requires:

Back 48

the removal of water to create a more complex molecule

Front 49

Which of the following are characteristics of electrolytes?

Back 49

a, b, and c are correct

Front 50

The reason the hemoglobin molecule qualifies as a quaternary protein structure is:

Back 50

it has four interacting globular subunits