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1

Chemical energy is __________.

energy stored in bonds between atoms and
a form of potential energy

2

Which of the following is an example of the conversion of potential energy into kinetic energy?

Synthesis of ATP from glucose
ATP hydrolysis to drive muscle contraction
Digestion of protein in the stomach
Pumping ions across a cell membrane

ATP hydrolysis to drive muscle contraction

3

The four elements that comprise 96% of living matter are __________.

carbon, hydrogen, nitrogen, oxygen

4

An atom's nucleus contains __________.

protons and neutrons

5

The element lithium has 3 protons and 4 neutrons in its nucleus. Its mass number is __________.

7

6

When atoms of two different elements bind together, they form a(n) __________.

compound

7

Which of the following mixture(s) are homogeneous?

Colloids
Solutions
Suspensions
Both colloids and suspensions

solutions

8

The most important determinant of an atom's bonding behavior is __________.

the number of valence shell electrons

9

When atoms gain electrons, __________.

the atoms become negatively charged

10

Ionic bonds connect atoms together by __________.

charge attractions

11

Covalent bonds occur when __________.

electrons are shared between atoms

12

An atom will tend to be electronegative if __________.

it lacks only 1–2 electrons in the valence shell

13

Water, H2O, is a polar molecule. Oxygen is electronegative and hydrogen is electropositive. This means that __________.

the oxygen pulls electrons away from hydrogen and becomes more negative

14

Hydrogen bonds are similar to ionic bonds because __________.

they both are due to opposite charge attractions

15

In a chemical reaction, ___________ join to form __________.

reactants; products

16

Water's unique properties like high heat capacity, high heat of vaporization, and universal solvent can be attributed to its __________.

ability to form hydrogen bonds

17

When chemical equilibrium is reached, __________.

no further net change in the amounts of reactants and products occurs

18

What will be the effect on a chemical reaction if the concentration of reactants is increased?

The speed of the reaction will increase.

19

A substance that is very acidic may have a pH of 1 or 2. This means that the acidic substance __________.

has a high concentration of H+ ions

20

A buffer will release H+ ions if the blood pH __________.

rises (becomes more basic)

21

The four major organic compounds that comprise our bodies are __________.

proteins, carbohydrates, lipids, nucleic acids

22

The major function of carbohydrates in the body is __________.

as cellular fuel

23

Which type of reaction occurs when biological molecules are broken down?

Hydrolysis

24

The three major subclasses of lipids include phospholipids, steroids, and __________.

triglycerides

25

The major building blocks for proteins are __________.

amino acids

26

Functions of proteins do not include acting as __________.

genes

27

The quaternary level of protein structure involves __________.

aggregations of polypeptides forming a complex protein

28

An enzyme's ____________ is the molecule upon which an enzyme acts.

substrate

29

Increasing the concentration of an enzyme's substrate (up to a point) would ___________ the reaction.

speed up

30

The major building blocks of nucleic acids are __________.

nucleotides

31

The four DNA nucleotides are __________.

adenine, thymine, cytosine, guanine

32

Which of the following is not a metabolic function of ATP?

Providing energy for diffusion

33

Substances that cannot be broken down into simpler substances are defined as ________.

elements

34

Energy in action is defined as _______ energy.

kinetic

35

When you row a boat, your arms provide which type of energy?

mechanical

36

When energy is converted from one form to another, some of the original energy is "lost" as ________.

heat

37

Which of the following is not one of the four major elements in the human body?

Hydrogen
Calcium
Nitrogen
Oxygen

calcium

38

The atomic number is always equal to the number of _______ in an atom.

protons

39

Isotopes have the same number of _______ but differ in the number of ________.

Isotopes have the same number of _______ but differ in the number of ________.

40

If an atom gains an electron, the resulting charge of that atom is more _________.

negative

41

Which spontaneously decompose into more stable atoms?

Radioisotopes

42

Which of the following is not a compound?

H2O
NaCl
O2
C6H12O6

o2

43

The following are electrons in the electron shells of four atoms. Which atom would most likely be reactive?

2, 8, 7

44

An ionic bond is formed between _______.

a cation and an anion

45

Which type of bond is formed when electrons are shared unequally between atoms?

Polar covalent

46

Which of the following statements is true of solvents?

They are usually solids.
They are present in smaller amounts in a solution.
Water is the main solvent in the body.
They are tiny particles.

Water is the main solvent in the body.

47

Building muscle tissue is an example of which type of reaction?

synthesis

48

All of the following affect the rate of a reaction except __________.

density

49

Bonds are broken during which type of reaction?

Catabolic

50

An enzyme is an example of a _________.

catalyst

51

Which of the following is not a reason for the irreversibility of chemical reactions in cells?

Chemical reactions that release energy would require energy to be reversed.
A product might be continually removed from the reaction site.
Biological reactions can only proceed in a single direction.
A product might be expelled from 
the body.

Biological reactions can only proceed in a single direction.

52

A steroid is an example of _________.

lipid

53

Which of the following is not a function of water?

Body temperature regulation
Source of electrolytes
Universal solvent
Protection from mechanical damage

Source of electrolytes

54

Which pH indicates a weak base?

2.0
6.8
7.4
11.0

7.4

55

Which of the following describes the tertiary structure of proteins?

α-helical or β-pleated regions of the polypeptide chain folded upon one another

56

A substance that dissociates into cations and hydroxyl ions is __________.

a base

57

Which substance is the primary energy-transferring molecule in the cell?

ATP

58

know the structure of lipid

mountain

59

know structure of functional protein

loop

60

know structure of nucleotide

valence bonds

61

know structure of polysaccharide

chain monosaccharides

62

know structure of monosaccharide

hexgonal box

63

know polymer structure

.

64

Know tertiary structure

.

65

know deoxyribose sugar

area

66

know thymine

area

67

know guanine

area

68

know phosphate

area

69

know hydrogen bond

area

70

bond which electrons are shared equally

polar covalent bond

71

bond in which electrons are completely lost or gained by the atoms involved

ionic bond

72

bond in which electrons are shared equally

nonpolar covalent bond

73

type of bond important in tying different parts of the same molecule together into a threedimensional
structure

hydrogen bond

74

Electrically charged particle due to loss of an electron

cation

75

Neutral subatomic particle

neutron

76

Smallest particle of an element that retains its properties

atom

77

Smallest particle of a compound that still retains its properties.

molecule

78

water

compound

79

carbon

element

80

dry ice

compound

81

blood

mixture

82

Can be measured only by its effects on matter

energy

83

Anything that occupies space and has mass

matter

84

Although a man who weighs 175 pounds on Earth would be lighter on the moon and heavier
on Jupiter, his ________ would not be different

mass

85

Is a function of, and varies with, gravity

weight

86

Legs moving the pedals of a bicycle

mechanical energy

87

When the bonds of ATP are broken, energy is released to do cellular work

chemical energy

88

Energy that travels in waves. Part of the electromagnetic spectrum

radiant energy

89

Represented by the flow of charged particles along a conductor, or the flow of ions across a
membrane

electrical energy

90

Heterogeneous, will not settle

colloids

91

Heterogeneous, will settle

suspension

92

Homogeneous, will not settle

solutions

93

Will not scatter light

solutions

94

First one or two letters of an element's name

atomic symbol

95

Number of protons in an atom

atomic number

96

Combined number of protons and neutrons in an atom

mass number of an element

97

The atomic weight is only an average of relative weights of an atom and its isotopes, and it
may vary from the weight of a specific isotope.

t/f

true

98

It is the difference in the R group that makes each amino acid chemically unique.

t/f

true

99

Chemical properties are determined primarily by neutrons

t/f

false

100

A charged particle is generally called an ion or electrolyte

t/f

true

101

Isotopes differ from each other only in the number of electrons the atom contains

t/f

false

102

About 60% to 80% of the volume of most living cells consists of organic compounds

t/f

false

103

Lipids are a poor source of stored energy

t/f

false

104

Current information suggests that omega-3 fatty acids decrease the risk of heart disease.

t/f

true

105

Glucose is an example of a monosaccharide

t/f

true

106

Glycogen, the storage form of glucose, is primarily stored in muscle tissue only

t/f

fase

107

The lower the pH, the higher the hydrogen ion concentration

t/f

true

108

Covalent bonds are generally less stable than ionic bonds

t/f

false

109

Hydrogen bonds are too weak to bind atoms together to form molecules but are important
intramolecular bonds.

t/f

true

110

The fact that no chemical bonding occurs between the components of a mixture is the chief
difference between mixtures and compounds

t/f

true

111

The acidity of a solution reflects the free hydrogen ions in the solution

t/f

true

112

A chemical bond is an energy relationship between outer electrons and neighboring atoms.

t/f

true

113

All organic compounds contain carbon.

t/f

true

114

A dipeptide can be broken into two amino acids by dehydration synthesis.

t/f

false

115

The pH of body fluids must remain fairly constant for the body to maintain homeostasis

t/f

true

116

Mixtures are combinations of elements or compounds that are physically blended together
but are not bound by chemical bonds

t/f

true

117

Buffers resist abrupt and large changes in the pH of the body by releasing or binding ions

t/f

true

118

The atomic number is equal to the number of ________.

protons, and electrons

119

Molecules such as methane that are made of atoms that share electrons have ________ bonds

covalent

120

An atom with three electrons would have a valence of ________.

one

121

AB → A + B is an example of a(n) ________ reaction.

decomposition

122

________ have a bitter taste, feel slippery, and are proton acceptors.

bases

123

A holoenzyme is composed of an apoenzyme and a(n) ________.

cofactor

124

In a DNA molecule, guanine would connect to ________.

cytosine

125

The ________ molecule directly provides energy for cellular work.

atp

126

Hydrogen bonds are more like a type of weak ________ than true bonds

atraction

127

Weak acids and bases make good ________.

buffers

128

Starch is the stored carbohydrate in plants, while ________ is the stored carbohydrate in
animals

glycogen

129

How many phosphates would AMP have attached to it?

1

130

Which metals have a toxic effect on the body?

heavy

131

What does the polar end of a phospholipid contain?

a phosphorus-containing group

132

What type of chemical bond can form between an element with 11 protons and an element
with 17 protons?

ionic

133

What happens when globular proteins are denatured?

activity sites are destoryed

134

Explain the difference between potential and kinetic energy.

Potential energy is inactive stored energy that has potential to do work. Kinetic energy

135

How can phospholipids form a film when mixed in water?

Phospholipids have both polar and nonpolar ends. The polar end interacts with water,
leaving the nonpolar end oriented in the opposite direction.

136

What properties does water have that make it a very versatile fluid?

High heat capacity, high heat of vaporization, polarity and solvent properties,
reactivity, and cushioning

137

What advantages does ATP have in being the energy currency molecule

Its energy is easy to capture and store; it releases just the right amount of energy for the
cell's needs so it is protected from excessive energy release. A universal energy currency is
efficient because a single system can be used by all the cells in the body.

138

Explain why chemical reactions in the body are often irreversible

Chemical reactions that release energy cannot be reversed unless energy is put back
into the system. Also, some reactions produce molecules in excessive quantities (like CO2 and
NH4) that the body then eliminates, but which are needed to reverse a reaction.

139

When a set of electrodes connected to a light bulb is placed in a solution of dextrose and a
current is applied, the light bulb does not light up. When the same unit is placed in HCl, it does.
Why?

HCl ionizes to form current-conducting electrolytes. Dextrose does not ionize, and
therefore does not conduct current

140

Describe the factors that affect chemical reaction rates

Temperature increases kinetic energy and therefore the force of molecular collisions.
Particle size: smaller particles move faster at the same temperature and therefore collide more
frequently; also, smaller particles have more surface area given the same concentration of
reactants. Concentration: the higher the concentration, the greater the chance of particles
colliding. Catalysts incr

141

Protons and electrons exist in every atom nucleus except hydrogen. Is this statement true or
false and why?

False. Hydrogen has one proton and one electron. It is the neutron, not the electron that
can coexist in the nucleus and that hydrogen does not have

142

A chemical bond never occurs between components of a mixture. Discuss this.

Mixtures come in three forms–solutions, colloids, and suspensions. Components of
these mixtures always retain their original makeup and can be separated into their individual
components; therefore no chemical bonding has taken place.

143

All chemical reactions are theoretically reversible. Comment on this statement

It is possible to reverse any reaction if the products are still present. Those that are only
slightly exergonic are easily reversible. Some would require an enormous amount of energy to
reverse. In the simple reaction Na + Cl → NaCl the amount of energy it takes to reverse table salt
to chlorine gas and sodium metal is enormous. The reversing of the covalently bonded sugar
molecule once it is reduced to ATP molecules is even harder or next to impossible without plantlike
systems

144

What is the major difference between polar and nonpolar covalent bonds?

Polar bonds have an unequal sharing of electrons resulting in a slight negative charge at
one end of the molecule and a slight positive charge at the other end. Nonpolar bonds have an
equal sharing of electrons, resulting in a balanced charge among the atoms.

145

An amino acid may act as a proton acceptor or donor. Explain

Amino acids have two components—a base group (proton acceptor) and an organic
acid part (a proton donor). Some have additional base or acid groups on the ends of their R
groups as well.

146

Name at least four things you know about enzymes

1. They are proteins.
2. They have specific binding sites for specific substrates.
3. They lower the activation barrier for a specific reaction.
4. The names end in "ase."
5. They can be denatured.
6. They can be used again and again.

147

In the compound H2CO3, what do the numbers 2 and 3 represent?

The 2 indicates that there are two hydrogen atoms in the compound and the 3 indicates
that there are three oxygen atoms in the compound.

148

Are all chemical reactions reversible? If not, why aren't they all reversible?

All chemical reactions are theoretically reversible, but only if the products are not
consumed.

149

If all protons, electrons, and neutrons are alike, regardless of the atom considered, what
determines the unique properties of each element?

Atoms of different elements are composed of different numbers of protons, electrons,
and neutrons.

150

An ionic bond is formed between _______.

cation and anion

151

Which type of bond is formed when electrons are shared unequally between atoms?

polar covalent

152

Which of the following statements is true of solvents?

water is the main solvent in body

153

All of the following affect the rate of a reaction except __________.

density

154

An enzyme is an example of a _________.

catalyst

155

Which of the following is not a reason for the irreversibility of chemical reactions in cells?

Biological reactions can only proceed in a single direction.

156

A steroid is an example of _________.

lipid

157

Which of the following is not a function of water?

source of electron

158

Which of the following describes the tertiary structure of proteins?

d. α-helical or β-pleated regions of the polypeptide chain folded upon one another

159

A substance that dissociates into cations and hydroxyl ions is __________.

base

160

Which substance is the primary energy-transferring molecule in the cell?

atp