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Flashcards in UNIT 1 EXAM Deck (386):
1

A(n) __________ refers to 2 or more atoms held together by covalent bonds.

Molecule

2

The core, or overarching theme of biology is

Evolution

3

All of the organisms on your campus make up

a community

4

Ecosystem dynamics include two major processes. What are they?

-chemical nutrients recycle. (chemicals cycle)
-energy flows

Nutrients are always recycled. Energy flows through the system, typically entering as solar energy and leaving as heat.

5

This kind of reasoning flows from specific observations to important generalizations

inductive reasoning

6

An ionic bond involves

an attraction between ions of an opposite charge

7

Trace elements are those required by an organism in only minute quantities. What is a trace element that is required by humans and other vertebrates?

Iodine

8

A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its likely classification?

Archaea

9

Which of the following best describes the logic of scientific inquiry?

If my hypothesis is correct, i can expect certain test results

10

Which kingdom within the domain Eukarya is composed of organisms that are generally unicellular (single-celled)?

Protista

11

Which series of terms is in the correct sequence of biological organization, from the simplest to the most complex?

(simplest is the smallest, then most complex is the bigger ones)

cell, tissue, organ, population, community

12

Emergent properties of living systems are defined as properties that

are due to the arrangement and interactions of parts as complexity increases.

13

Emergent properties

are novel properties not present at the level of biological organization just below.
Emergent properties arise from the arrangement and interactions of parts as complexity increases.

14

Which of the following is an example of qualitative data?

The fish swam in a zigzag motion

15

Which of the following statements is most clearly inductively derived?

If the animals observed require organic molecules as nutrients, then it can be concluded that all animals require organic molecules as nutrients.

16

Induction moves from a set of

specific observations (humans require organic molecules, fish require organic molecules, etc) to reach a general conclusion (all animals require organic molecules).

17

Eukaryotic organisms that decompose dead organisms and absorb nutrients are generally found in which kingdom?

Fungi

18

Kingdom Fungi are

eukaryotic decomposers that obtain their nutrients by breaking down dead organisms and organic wastes.

19

Protists and bacteria are grouped into different domains because

protists have a membrane-bounded nucleus, which bacterial cells lack

20

At which point is a scientific investigator most likely to use deductive reasoning?

in establishing a test of a hypothesis.

21

In deduction, reasoning flows from

the general to the specific.
Deductive testing would take the form of "if...then" logic.

22

The best method for determining whether bean plants require sodium is to

grow bean plants with and without sodium.

23

In hypothesis-based scientific inquiry,

the experiment must have an experimental group and a control group.
In the case of whether the bean plants require sodium, growing bean plants with sodium would constitute the experimental group, and growing bean plants without the addition of sodium would constitute the control group.

24

A company was testing a new drug it thought would help decrease the risk of transmission of viruses from mother to fetus. In an experiment to test the compound, an investigator gave 400 pregnant female rats a small dose of the experimental drug and inoculated each with a type of virus known to cause disease in rats. At the same time, 400 other pregnant rats were given only the virus. Of the rat pups born to the females that received both the virus and the drug, 203 showed no symptoms of the disease; 205 rat pups born to the virus only females showed symptoms. From these data, we can best conclude

that the drug seems to have little effect on viral transmission at the dosage given.

Approximately equal numbers of pups were affected in both groups (experimental group 400-203=197, control group=205), suggesting that the drug was probably not effective at the dosage given.

25

A theory is

a well-supported concept that has broad explanatory power.

26

Theories are

comprehensive and become widely accepted if they are supported by a large body of evidence

27

Which of the following is outside the realm of scientific inquiry?

addressing ethical dilemmas.

Questions of ethics are not amenable to solution by experiments or observations.

28

Which of the following can be considered a biological system?

a pond, the biosphere, a single liver cell, and a salmon's cardiovascular system.

29

A (Biological) system is a

combination of components that function together. It can be defined at any scale.

30

Two garden plots were planted with corn. The soil was similar in each, and equal amounts of water were applied to each plot. One plot was fertilized, and the other was not. The experimenters measured the yield as bushels of corn from each plot. The plot that did not receive the fertilizer was the

control plot.

The control refers to the plot that does not receive experimental treatment or the variable being test, in this case, the fertilizer.

31

What is the fundamental unit of structure and function in living organisms?

cell

32

The cell is the

fundamental structural and functional unit of both single-celled and multicellular organisms.

33

Natural selection tends to act at which level?

Population.

34

Natural selection selects for

organisms within a population that are best adapted to their local environment.

35

Which of the following statements best describes what is meant by "emergence"?

The whole is greater than the sum of the parts.

36

In experimental procedures, repetition of the procedures

is necessary before concluding that a given set of results is correct.

37

Repetition of tests is

crucial to the process of science. Only when a result is repeatable can it be considered correct.

38

What are some observations or inferences on which Darwin's theory of natural selection is based?

-A population can become adapted to its environment over time.
-There is heritable variation among individuals.
-Because of the overproduction of offspring, there is competition for limited resources.
-Individuals whose inherited characteristics best fit them to the environment will generally produce more offspring.

39

Which is NOT an observation or inference on which Darwin's theory of natural selection is based?

Poorly adapted individuals never produce offspring.

40

A controlled experiment is one that

tests experimental and control groups in parallel

41

A hypothesis must be testable and falsifiable to be scientifically valid. Being testable and falsifiable means that

some conceivable observation or experiment could reveal whether a given hypothesis is incorrect.

42

Hypotheses should be phrased

in a way that enables one to make predictions that can be tested and falsified by experiments or observations.

43

With evolution as the core theme of biology, we can explain traits shared by organisms as evidence of ______ and traits that differ among organisms as evidence of _______.

descent from a common ancestor . . . adaptation through natural selection.

44

Many shared traits have been

derived from common ancestry. The modifications to those shared traits can usually be attributed to adaption evolution by natural selection.

45

Which of the following domains is prokaryotic?

Archaea.

46

Domain Archaea are

among the simplest kinds of organisms, the prokaryotes.

47

How is the information encoded in DNA actually used by organisms?

The information in DNA is transcribed to RNA and then translated into protein.

48

What is the appropriate term for an interacting group of individuals of a single type occupying a defined area?

a population.

49

Only the organisms of a given species that have the opportunity to interact with one another are considered to be

within the same population

50

Radon is a radioactive gas that seeps into homes from the soil. It is thought to be a cause of lung cancer. A research team investigates this theory. They gather large amounts of data on basement radon concentrations and lung cancer rates and conclude that the more radon there is in a home, the more likely are people living in those homes to develop lung cancer. After the study is published, other researches criticize it by asserting that the studied neighborhoods with higher radon concentrations also have a higher percentage of older people and a higher percentage of cigarette smokers than the low-radon neighborhoods. Both advanced age and cigarette smoking increase the risk of lung cancer. This criticism, if correct, shows that the radon study suffered from

uncontrolled variables.

51

An important feature of the scientific process is the

controlled experiment in which two groups are established and treated exactly alike, except for the one variable that the experiment is designed to test.

52

Which of the following best describes the unity among all organisms?

the structure and function of DNA

53

Systems biology is mainly an attempt to

understand the behavior of entire biological systems

54

Experimentation is only one part of the process of scientific inquiry, but it is a very important step because it

allows rejection of a hypotheses

55

Experimentation is important because

hypotheses can be rejected if contradictory evidence emergences

56

Which of the following is an attribute of living things?

They must be able to evolve and adapt.

57

The energy used by most organisms for metabolism and growth ultimately comes from

the sun.

58

Energy for most life ultimately comes from

the light energy of the sun, trapped in the chemical bonds of molecules synthesized by photosynthetic organisms.

59

What is the molecule that can account for both the unity and the diversity of life?

DNA

60

The uniformity of coding in DNA is

virtually universal. Life's variety arises from variations in the nucleotide sequences of inherited DNA molecules, the substance of genes.

61

What are some attributes of living things?

-All living things maintain complexity of order.
-Populations of living things evolve.
-All living things use DNA as their genetic material.
-They convert energy from one form to another.

62

Which is NOT an attribute of living things?

All living things require oxygen

63

There are many species of bacteria that live in the absence of

oxygen.
So, all living things do NOT require oxygen.

64

What are some examples of emergence?

-A calculator
-An organ
-Bees making a beehive
-Water's high specific heat

65

Emergence is not restricted to

biological systems

66

Which of the following statements best distinguishes hypotheses from theories in science?

Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.

67

Should an experiment test only one variable at a time?

Yes, an experiment should only test one variable at a time. This ensures that the experimental outcome is clearly due to one identifiable factor.

68

Treatment of an experimental group should differ from treatment of a

control group by only a single variable so that the researcher can determine what causes the observed effect.

69

A particular carbon isotope has an atomic number of 6 and an atomic mass of 14. The respective number of neutrons, protons, and electrons that this carbon isotope has is

8, 6, and 6

70

Evaluate the following statement: Oxygen is not a greenhouse gas; therefore, gases containing oxygen, such as ozone, nitrous oxide, and carbon dioxide, are not greenhouse gases either.

False. Compounds can have emergent properties that are very different from the elements that form them.

71

Emergent properties of compounds are

more than simply the sum of their parts.

72

Compounds represent a higher level of organization than

elements and can have characteristics that are different than the elements that compose them.

73

For most atoms, a stable configuration of electrons is attained when the atom

has eight electrons in its outermost shell

74

An atom with a complete valence shell is

unreactive

75

Which of the following four statements, if any, is true regarding essential elements and living organisms?

Although all forms of life require iron, other elements are required only by certain species.

76

Humans and other vertebrates require small amounts of

iodine in their diets to maintain thyroid function. This is a requirement not observed among invertebrates.

77

The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium?

an atom with 20 protons, 21 neutrons, and 20 electrons

78

Isotopes of an element have the same number of protons but different numbers of

neutrons

79

Pharmaceutical researches are often interested in blocking particular receptor proteins on cell surfaces. What chemical property of a molecule would be most important for this type of application?

the molecule's shape.
The molecule would have to have te correct shape to bind to the receptor protein and block it.

80

Ionic bonds form as a result of

attraction between ions that have opposite charges

81

Oppositely charged ions attract each other electrically, forming an

ionic bond.

82

Isotopes of an element will always differ in

atomic mass

83

Atomic mass refers to the number of

protons and neutrons in an atom.

84

Atomic forms of an element with the same number of protons (atomic number) but different number of neutrons are

isotopes of that element

85

A sodium atom has a mass number of 23. Its atomic number is 11. How many electrons doe it have it if is not an ion?

11

86

The number of electrons will equal the number of

protons in an electrically neutral atom

87

Which of the following statements correctly describes any chemical reaction that has reached equilibrium?

The rates of the forward and reverse reactions are equal.

88

What are the four most abundant elements found in living systems?

Hydrogen, oxygen, nitrogen, and carbon

89

Hydrogen, oxygen, nitrogen, and carbon make up about

96% of living matter

90

Compared with 31P, the radioactive isotope 32P has

one more neutron

91

How many electrons would be present in the valence shell of a sulfur atom (atomic number 16, mass number 32)?

six electrons

92

We can represent atoms by listing the number of protons, neutrons, and electrons-for example, 2p+. 2n0, 2e- for helium. Which of the following represents the 18O isotope of oxygen?

8p+, 10n0, 8e-

93

What coefficients must be placed in the following blanks so that all atoms are accounted for in the products?
C6H12O6 S _______ C2H6O + _________CO2

2;2

94

Evaluate the following statement: Concentrations of trace elements in the environment above what is required by organisms generally has no effect on those organisms.

False. Elevated concentrations of some trace elements such as cobalt and chromium can be toxic.

Some nonessential elements are known to be toxic to organisms.

95

What is the role of van der Waals interactions in biological molecules?

Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules.

96

Weak bonds are important in the three-dimensional structure of

most large biological molecules, and they play a role in molecular interactions.

97

In the term trace element, the adjective trace means that

the element is required in very small amounts.

98

Some groups of elements react chemically in similar ways. For example, the chemistry of sodium and the chemistry of lithium are similar. The chemistry of chlorine and the chemistry of iodine are also similar. These similarities in chemistry result when different elements hace similar

numbers of outer-shell electrons

99

Atoms with the same number of electrons in their valence shells

exhibit similar chemical behavior or reactivity

100

Which of the following subatomic particles has appreciable mass and lacks a charge?

Neutron

101

A neutron weighs about

1.7 x 10-24 grams (has a mass close to 1 dalton), and it is electrically neutral

102

A covalent bond is likely to be polar if

one of the atoms sharing electrons is much more electronegative

103

If one atom is more electronegative than the other,

electrons of the bond will not be shared equally, resulting in a polar covalent bond.

104

Copper has an atomic number of 29 and a mass number of 64. What would result if an uncharged copper atom lost two electrons?

The atomic number would remain 29, the mass number would remain 64, and the atom would be a cation with a 2+ charge.

105

The loss or gain of an electron(s) does not influence the

atomic number (number of protons) or the mass number (number of protons plus neutrons) of an atom.

106

What is an example of a trace element?

Copper

107

The number of protons in an uncharged atom

equals the number of electrons

108

An uncharged atom has an equal number of

protons and electrons

109

An element has 8 protons, 9 neutrons, and 8 electrons, Its atomic number and atomic mass, respectively, are

8 and 17

110

A polar covalent bond is a bond that

has shared electrons pulled closer to the more electronegative atom

111

Polar covalent bonds share electrons

unequally, so that one part of the molecule has a partial negative region and one part a partial positive region.

112

There are ____ naturally occurring elements.

92.

About 25 of the 92 are essential to life.

113

WHen the proton number and electron number are unequal, the atom or molecule

is an ion

114

WHen the proton number and electron number are unequal,

the atom or molecule has a net positive (cation) or negative charge (anion).

115

Which of the following molecules has the shape of a completed tetrahedron?

methane (CH4).

The nucleus of the carbon atom is at the center of the tetrahedron, with its four covalent bonds radiating to the hydrogen nuclei at the corners of the tetrahedron.

116

Which statement is true of all atoms that are anions?

The atom has more electrons than protons.

117

A hydrogen bond

is a weak chemical bond

118

Hydrogen bonds are

weak chemical bonds that are very important in the chemistry of life

119

The chemical characteristics or reactivity of an element depend mostly on the

number of electrons in its outermost shell

120

Only electrons are directly involved in the

interactions between atoms, and the number of electrons in the outermost shell determines the chemical behavior or reactivity of an atom.

121

An atom that normally has ____ in its outer shell would not tend to form chemical bonds with other atoms.

eight electrons

122

Eight electrons in the outer shell will leave

no unpaired electrons in the valence shell. IN this configuration atoms are chemically unreactive or inert.

123

The reactivity of an atom arises from

the existence of unpaired electrons in the valence shell

124

The compound CaSO4 ionizes into a calcium ion and a sulfate ion (SO4). Calcium has two electrons in its outer shell. Upon ionization, what would you expect the charge on the sulfate ion to be?

-2.
By gaining two electrons from calcium, the sulfate ion now has a charge of -2 and calcium has a charge of +2.

125

Which of the following has negligible mass?

electron.
The mass of an electron is only about 1/2000 that of a proton or neutron, electrons are not considered when computing atomic mass.

126

An uncharged atom of nitrogen (atomic number=7_ has

seven protons and seven electrons.

127

The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound.

H2S

128

Which of the following states describes a reversible reaction that has reached chemical equilibrium.

The rate of the reverse reaction equals the rate of the forward reaction

129

When one or more pairs of valence electrons are shared by two neutral atoms, what type of bond is formed?

a covalent bond

130

Covalent bonds are formed between atoms that

share one or more pairs of valence electrons

131

What is the strongest type of bond?

A covalent bond

132

Water is a polar molecule. This means that

the opposite ends of the molecule have opposite electrical charges

133

In the case of water, oxygen is slightly negative and the hydrogen atoms are slightly

positive

134

Why is the increasing amount of carbon dioxide being taken up by the oceans a cause for concern?

More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to a decrease in the concentration of carbonate ion (CO32).

135

As seawater becomes more acidic,

carbonate ion concentration decreases. The decrease in the availability of carbonate ion makes it more difficult for marine organisms to secrete calcium carbonate shells.

136

Most of water's unique features (for example, its versatility as a solvent, ability to moderate temperature, and cohesive behavior) result from the fact that

oxygen attracts electrons more than hydrogen does

137

Because oxygen is more electronegative than hydrogen,

water molecules are polar and form hydrogen bonds that give water its extraordinary properties

138

A glass of grapefruit juice, at pH 3, contains _____ H+ as a glass of a tomato juice, at pH4.

ten times as much

139

The pH scale is a base-10 logarithmic scale. The change from any pH value to the next smaller value represents a

tenfold increase in the hydrogen ion concentration

140

A solution at pH 6 contains ______ than the same amount of solution at pH 8.

100 times more H+

141

Pure water has a pH of 7. Why does uncontaminated rainwater have a pH of 5.6?

formation of carbonic acid from carbon dioxide and water.

142

The presence of carbonic acid in rainwater causes it to have a

lower pH that pure water.

143

Which of the following accurately relates the emergent properties of water to the effects of global warming in the Arctic?

The significant increase in Arctic air temperature over the past 50 years is causing sea ice to form later in the year, to melt earlier, and to cover a smaller area each year.

The warming that has occurred in the Arctic has significantly affected the seasonal balance between ice and liquid water to the degree that sea ice communities are in danger.

144

Sweating has a cooling effect because of water's high

heat of vaporization.

145

Water's high heat of vaporization results in

evaporative cooling because when water evaporates, the surface of the water cools down.

146

Which of the following statements is true about acid precipitation?

It washes away some minerals that are plant nutrients, and causes some toxic minerals to accumulate.

Important plant nutrients such as calcium and magnesium may be washed away from the soil, and aluminum may build up to dangerous levels.

147

Water molecules have _______ than molecules of similar size, such as ammonia and methane, reflecting its capacity to absorb large amounts of heat.

a higher boiling point.

More heat is needed to vaporize 1 g of water than most other liquids.

148

The phenomenon responsible for maintaining the upward movement of water through a vessel is

cohesion

149

Cohesion is a consequence of

hydrogen bonding between water molecules

150

Because molecules of water are farther apart in ice than in liquid water,

ice floats

151

Because water molecules in ice are farther apart than in liquid water,

ice is less dense, and therefore, it floats

152

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

number of molecules

153

An acid is

a compound that donates hydrogen ions to a solution

154

Hydrophobic molecules are ____ water

repelled by

155

Substances that are nonionic and nonpolar

repel water and are termed hydrophobic

156

The bonds that are broken when water vaporizes are

hydrogen bonds between water molecules

157

The absorption of human-generated CO2 by the oceans

increases the hydrogen ion concentration in the oceans but decreases the carbonate ion concentration and threatens the livability of the oceans for calcifying organisms

158

Thee absorption of CO2 by the oceans causes an increase in the carbonic acid, and hydrogen ion concentration (lower pH). The extra hydrogen ions bind wit the carbonate ion to form

bicarbonate. This reduces the amount of carbonate ions available for calcification, the production of calcium carbonate (CaCO3) by many marine organisms, including reef-building corals and animals that build shells.

159

If water were not a polar molecule, how would the effects of global warming differ from what are currently observed or predicted to occur in the future?

The effects would be drastically worse because the loss of the polar nature of water would greatly reduce its specific heat and its ability to moderate temperature.

160

A loss of the polar nature of water would equate to a loss in the ability to form

hydrogen bonds. Breaking hydrogen bonds absorbs energy, which accounts for water's high specific heat and its ability to influence and moderate climate.

161

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

10-4 M

(10^-4 M)

162

Why are cell membranes composed primarily of hydrophobic molecules?

In order to perform their function of separating the aqueous solutions outside of cells from the aqueous solutions inside of cells, cell membranes cannot be soluble in water.

163

If cell membranes were hydrophilic,

they would break down and dissolve in the presence of water, rendering them useless as a barrier.

164

Nonpolar molecules that cluster away from water molecules are called ______ molecules

hydrophobic

165

Substances that are nonionic and nonpolar

repel water

166

The tendency of water molecules to stay close to each other as a result of hydrogen bonding

-acts to moderate temperature
-keeps water moving through the vessels in a tree trunk
-is called cohesion
-and provides the surface tension that allows leaves to float on water

167

A molecule that has all nonpolar covalent bonds would be

hydrophobic

168

The hydrophobic behavior of oil molecules results from a

prevalence of nonpolar covalent bonds. Nonpolar molecules do not have an affinity for water or other polar molecules.

169

What do cohesion, surface tension, and adhesion have in common with reference to water?

All are properties related to hydrogen bonding.

170

The extraordinary qualities of water are emergent properties resulting from

hydrogen bonding

171

When the pH of a solution shifts from 7 to 3, how has the hydrogen ion concentration changed?

It has increased by 10,000 times.

Because the pH number is the negative log of the hydrogen ion concentration, a change from a pH of 7 to a pH of 3 increases the hydrogen ion concentration by 10,000 times. (7-3=4; 10^4=10,000).

172

What water-related evidence do scientists have that suggests life may exist on other planets?

In 2008, the robotic spacecraft Phoenix found ice present just under the material on Mars's surface, and detected sufficient water vapor in the Martian atmosphere for frost to form.

Although life-forms haven't been found on Mars, these new findings have reinvigorated the search for signs of life, past or present, on Mars and other planets.

173

The reason that coastal climates are more moderate than inland climates is due primarily to water's high

specific heat.

174

Because of water's high specific heat,

water's temperature will change less when it absorbs or loses a given amount of heat. Thus, the oceans can absorb and store a huge amount of heat and release it later when the temperature or the air has dropped.

175

The amount of heat required to change the temperature of 1 g of any substance by one C is defined as

the specific heat of that substance.

176

The specific heat of a substance is defined as the

amount of heat that must be absorbed or lost to change the temperature of 1 g of that substance by one C.

177

Cells are surrounded by water, and cells themselves consist of about 70 to 95% water. As a result,

-the temperature of living things tend to change relatively slowly
-waste products produced by cell metabolism can be easily removed
-a variety of nutrient molecules is readily available as dissolved solutes
-and dissolved substances can be easily transported within a cell or between cells in multicellular organisms

178

Which of the following is a hydrophobic material?

wax

179

Adhesion is best described as

the clinging of one substance to another substance

180

Adhesion is the attraction

of one substance to another

181

You can fill a glass of water to just slightly above the rim without it spilling over the glass. What property of water best explains this phenomenon?

surface tension

182

Water has a greater surface tension,

a measure of how difficult it is to break the surface of a liquid, than most other liquids

183

The partial charges on a water molecule occur because of

the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule

184

Because oxygen is more electronegative than hydrogen,

electrons of the polar bond spend more time closer to the oxygen atom, resulting in a slight negative charge on the oxygen atom and slight positive charges on the hydrogen atoms.

185

Water is a very versatile solvent because water molecules are

polar

186

Because molecules of polar solvents have a positive and a negative pole,

polar solvents are excellent solvents for ions and for other polar materials

187

The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as

the heat of vaporization of that substance

188

Heat of vaporization is the

quantity of heat a liquid must absorb for 1 h of it to be converted from the liquid to the gaseous state.

189

Which action would involve the greatest transfer of heat?

condensing 5 g of steam to liquid water.

This would release about 2,900 calories (580 calories/gram x 5 grams).

190

In a group of water molecules, hydrogen bonds form between

the oxygen atom in one water molecule and a hydrogen atom in another water molecule

191

The slightly negatively charged region of an oxygen atom of one water molecule is attracted to the

slightly positively charged region of a hydrogen atom of another water molecule

192

Adding acid tends to ______ of a solution

increase the hydrogen ion concentration and lower the pH

193

Because pH is a negative log,

its value is inversely proportional to the hydrogen ion concentration

194

A substance that minimizes changes in the concentration of H+ and OH- in a solution is a

buffer

195

Buffers are substances that

minimize changes in the concentration of hydrogen ions and hydroxide ions in a solution; therefore, buffers maintain a relatively constant pH.

196

Which of the following hydrocarbons has a double bond in its carbon skeleton?

C2H4

197

Which of the following examples describes a unique functional property of the carboxyl group?

the covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.

198

Which of the following molecules is a weak base?

R-NH2

The amino group (-NH2) of R-NH2 can function as a base. It can accept a proton (H+).

199

Pharmaceutical companies are selling close to $200 billion worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?

One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic.

Depending on the body's ability to recognize and use different enantiomers, one version may have dangerous effects, as in the case of methamphetamine.

200

Carboxyl is to _______ as ________ is to base.

Acid ...... amino

201

A carboxyl group has

acidic properties because it can donate a proton (hydrogen ion) to a solution. The amino group acts as a base because it can pick up or accept a proton (hydrogen ion) from a solution.

202

A pharmaceutical company was forced to recall a pain reliever medication that had been linked to the fatalities of several hundred people. Analysis of the recalled drug revealed the presence of two isomers due to an asymmetrical carbon atom in the drug molecule. What can be hypothesized from this observation?

The isomers are enantiomers, with one having toxic effects on humans.

203

Enantiomers are isomers that are

mirror images of each other and that differ in shape due to the presence of an asymmetric carbon. The remarkable sensitivity of organisms means that subtle differences in molecular structure can translate to different and unintended effects on organism function.

204

Organic chemistry is currently defined as

the study of carbon compounds

205

Which functional group would you predict is part of abscisic acid (ABA)?

Carboxyl

206

Compounds containing the carboxyl functional group (-COOH) are known as

carboxylic acids or organic acids. They can donate a hydrogen ion (proton) to a solution due to a highly polar oxygen atom of the functional group.

207

Using modern equipment, a former graduate student of Stanley Miller recently reanalyzed the sample results of volcano simulation experiments that Miller conducted along with his classis experiment described in the test. This reanalysis

identified additional organic compounds that had not been found by Miller.

208

Although the structures of the functional groups that are the most important in life vary, they share one thing in common: They

all are hydrophilic and increase the organic compound's water solubility.

209

Functional groups are all

hydrophilic

210

Glucose and hexanoic acid each contain six carbon atoms, but they have completely different properties. Glucose is a nutrient found in food; hexanoic acid is poisonous. Their differences must be due to different

functional groups

211

Functional groups most commonly determine

chemical properties such as the polarity and reactivity of molecules

212

At the beginning of the 19th century, it was thought that the substances that made up living things were special and could not be synthesized by ordinary chemical methods. This now-discarded theory was called the theory of

vitalism

213

Vitalism is a belief in a

life force outside the jurisdiction of physical and chemical laws

214

The first organic molecule to be synthesized from inorganic substances that could be prepared directly from inorganic substances was

acetic acid

215

Acetic acid was the first organic molecule synthesized from

nothing but inorganic substances

216

Carbon atoms are the most versatile building blocks of the molecules used by living organisms because

each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions

217

Carbon has the potential to form molecules that can be

straight, branched, or ringed. Along with the ability to form double and triple bonds, this ability permits the formation of an almost infinite number of different molecules

218

Which of the following functional groups is present in all amino acids?

-NH2

This is the amino group. This group is present in all amino acids.

219

The ionized or dissociated carboxyl group may be written as

-COO-

220

The carboxyl functional group (-COOH) is an

oxygen atom double-bonded to a carbon atom that is also bonded to a hydroxyl group. When a proton or hydrogen ion dissociates from the group, the negatively charged -COO- is the result

221

What is the three-dimensional shape created by hybrid orbitals that are formed when a carbon atom is covalently bonded with four other atoms?

a tetrahedron with carbon in the center.

The pairs of bonding electrons are oriented as distantly as possible from one another in a tetrahedron with the carbon atom at the center and the other four atoms at the vertices of the tetrahedron.

222

Which of the following are properties of hydrocarbons?

hydrophobic, nonpolar, good source of stored energy.

223

Because they are nonpolar, hydrocarbons are

hydrophobic. They also provide energy in the forms of things such as fossil fuels and fats.

224

A thiol is a molecule containing a

sulfhydryl functional group

225

which of the following functional groups is associated with a release of energy when removed from the carbon skeleton with water that cells can harvest to perform many functions?

phosphate.

Cleaving a phosphate group from ATP releases energy that is used to perform many cellular functions

226

Which chemical group is most likely to be responsible for an organic molecule behaving as a base?

amino

227

What are the six more important chemical elements of life?

carbon, nitrogen, oxygen, hydrogen, phosphate, sulfur.

These are all capable of forming strong covalent bonds, important in building large, complex molecules

228

Which of the following molecules has a carboxyl functional group?

R-COOH

The molecule R-COOH contains the carboxyl functional group (-COOH). The presence of this group would make the molecule a weak acid

229

A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different geometric isomers exist for this molecule?

two.

Only two geometric isomers exist. The number of structural isomers, however, is larger

230

Stanley Miller's experiments were significant because he demonstrated that

a variety of simple organic compounds could be spontaneously synthesized from components in Earth's primitive atmosphere.

By discharging an electrode in a mixture similar to Earth's primitive atmosphere, Miller was able to synthesize a variety of simple organic molecules.

231

The carbon atom is tetravalent; this means that

a carbon atom can complete its valence shell by forming four covalent bonds

232

With four valence electrons, carbon usually shares its four electrons in covalent bonds to

complete its outer shell

233

A straight-chain carbon compound constructed from ______ must obtain at least one carbon-carbon double bond.

six hydrogen, three carbon.

234

Which of the following functional groups increases the solubility of organic compounds in water?

-NH2
-COH
-COOH
-SH

All of the functional groups are hydrophilic and thus increase the solubility of organic molecules in water

235

Which of the following groups is capable of hydrogen bonding with an oxygen atom on another functional group?

-Amino
-Sulfhydryl
-Hydroxyl
-and Carboxylic acid.

All of the listed functional groups are polar, thus capable of hydrogen bonding with the oxygen of another molecule

236

Which of these is found in all amino acids?

both -COOH and -NH2

237

For a compound to be an amino acid,

it must contain at least one carboxyl functional group and one amino functional group. In addition, it may contain one or more of the other functional groups

238

Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they

all share the same functional group: a hydroxy

239

Alcohols are distinguished by the presence of the

hydroxyl (-OH) functional group

240

Which action could produce a carbonyl group?

the replacement of the -OH of a carboxyl group with hydrogen

241

Which is an organic molecule?

CH4

242

Compounds containing carbon are said to be

organic

243

What is ATP's importance in the cell?

ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.

ATP releases energy during a hydrolysis reaction that removes a phosphate group

244

Which element is always associated with organic chemistry?

carbon

245

The water molecule is a

polar molecule: the opposite ends have opposite charges

246

polarity allows water molecules to form

hydrogen bonds with eachother

(KNOW HOW TO DRAW A WATER MOLECULE AND WHERE THERE ARE COVALENT BONDS AND HYDROGEN BONDS)

247

in a water molecule, oxygen is

electronegative

248

polar means that

electrons are shared unequally

249

Four of water's properties that facilitate an environment for life are

(Water's 4 emergent properties)

1. cohesive behavior
2. ability to moderate temperature
3. expansion upon freezing
4. versatility as a solvent

They all occur because water molecules are electrically attracted to one another

250

Cohesion of water molecules

Water molecules stay close to one another because of hydrogen bonding.

It happens in all forms (solid, liquid, gas).
H-bonds are fragile (1/20) but collectively strong.

Collectively hydrogen bonds hold water molecules together by a phenomenon called cohesion.

251

Cohesion

water likes to stick to water

252

Hydrogen bonds are why it is

cohesive

253

Cohesion helps the transport of

water against gravity in plants.
As water evaporates, more is pulled upward.

254

Adhesion is

an attraction between different substances, for example, between water and plant cell walls.

255

Adhesion

water sticking to other stuff

256

Surface tension is

a measure of how hard it is to break the surface of a liquid

257

surface tension is related to

cohesion.
the surface of water is an organized arrangement of water molecules that are H-bonded to the molecules below and the water below.

An invisible film.
-water striders
-glass of water

258

Moderation of temperature by water

water absorbs heat from warmer air and releases stored heat to cooler air.
water can absorb or release a large amount of heat with only a slight change in its own temperature

259

Heat is

a measure of the TOTAL amount of kinetic energy due to molecular motion.

260

Temperature measures

the intensity of heat due to the AVERAGE kinetic energy of molecules.

As the average speed of molecules increases we see an increase in the temperature.
Ex. a swimmer in the ocean has higher temperature than the water, but the ocean has more heat because of its volume.

261

Kinetic Energy

is the energy of motion

262

0 degrees celsius is

where water freezes

263

25 degrees celsius is

room temperature

264

37 degrees celsius is

body temperature

265

100 degrees celsius is

where water boils

266

Water's high specific heat can be traced to

hydrogen bonding

267

heat is absorbed when

hydrogen bonds break

268

heat is released when

hydrogen bonds form

269

the high specific heat of water

minimizes temperature fluctuations within limits that permit life.
ex. oceans and organisms

270

evaporation

is the transformation of a substance from liquid to gas

271

Heat of evaporation

is the heat a liquid must absorb for 1g to be converted to gas

272

Evaporative cooling

a process that as a liquid evaporates, its remaning surface cools

the "hottest" molecules leave.

273

Evaporative cooling of water helps

stabilize temperatures.
Sweating humans, sweating plants.
Humidity inhibits evaporative cooling

274

Ice floats in liquid water because

hydrogen bonds in ice are more "ordered" making ice less dense

275

if ice sank,

all bodies of water would eventually freeze solid, making life impossible on earth

276

Expansion upon freezing

ice floats

277

Versatility as a solvent
Water: the solvent of life

solution=solvent + solute

278

a solution is

a liquid that is a homogenous mixture of substances.
A big mixture.
ex. salt water, sugar water, kool-aid

279

A solvent is

the dissolving agent of a solution
the wet stuff.
ex. water, alcohol

280

The solute is

the substance that is dissolved
the chalks/chunks/dissolved stuff.
ex. salt, sugar

281

An aqueous solution is

one in which water is the solvent

282

water is a versatile solvent due to

its polarity, which allows it to form hydrogen bonds easily.

283

when an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called a

hydration shell

284

water can dissolve anything that is

ionic

285

water is the solvent of

life

286

Example of water expanding when frozen

ice floating in water

287

Examples of moderating temperature

sweating, ice cubes in a glass, going in the ocean

288

Example of cohesion

towel drying you off, bug sticking on top of water

289

A hydrophilic substance

is one that has an affinity for water.
water loving.

290

a hydrophobic substance

is one that does not have an affinity for water.
water hating.

291

oil molecules are

hydrophobic because they have relatively nonpolar bonds.

292

molecular mass is

the sum of all masses of all atoms in a molecule.
Take the mass of each atom and add them.

293

Numbers of molecules are usually measured in

moles, where 1 mole (mol)= 6.02 x 10^23 molecules.

294

avogadro's number and the unit dalton were defined such that

6.02 x 10^23 = 1 g

295

the molecular mass of something can be

any number of grams and = 1 mole

296

Molarity (M) is

the number of moles of solute per liter of solution

297

The hydrogen atom leaves its electron behind and is transferred as a proton, or a

hydrogen ion (H+)

298

the molecule with the extra proton is now a

hydronium ion (H3O^+), though its often represented as H+

299

The molecule that lost the proton is now a

hydroxide ion (OH-)

300

Water is at a state of dynamic equilibrium in which

water molecules dissociate at the same rate at which they are being formed

301

Concentrations of H+ and OH- are

equal in pure water

302

An acid is

any substance that INCREASES the H+ concentration of a solution.
Donates H+
have more hydrogens

303

A base is

any substance that REDUCES the H+ concentration of a solution
have less hydrogens.
Donates OH- that interact with H+ to form water (NaOH)

304

A base is NOT defined as something that

adds OH-

305

pH=

concentration of hydrogen ions
the exponent

306

pH scale is a

long scale.
10 times differences between each consecutive number (like between 1 and 2, between 5 and 6, etc)

307

the pH scale is all about whats going on with

hydrogens

308

in any aqueous solution at 25 degrees celsius the product of H+ and OH- is constant and can be written as

[H+][OH-]=10^-14

309

For a neutral aqueous solution,

[H+] is 10^-7, so pH= -(7)=7

310

Acidic solutions have pH values

less than 7

311

Basic solutions have pH values

greater than 7

312

Acids increase hydrogens H+ but

acids are the lower numbers on the pH scale.
its an inverse relationship.

313

the internal pH of most living cells must remain close to

pH 7

314

Buffers are

substances that minimize changes in concentrations of H+ and OH- in a solution.

315

Most buffers consist of an

acid base pair that reversibly combines with H+

316

buffers try to

maintain a set point

317

confliction of blood vessels causes

wrinkling of skin on fingers because of the sympathetic nervous system.

318

organic chemistry is

the study of compounds that contain carbon.
study of carbons

319

organic compounds range from simple molecules to

colossal ones.
methane, protein, DNA, carbohydrates

320

Most organic compounds contain

hydrogen atoms in addition to carbon atoms

321

Although C,H,O,N ratios are uniform from one organisms to another, carbon's versatility allows for an

inexhaustible variety of organic molecules

322

vitalism

the idea that organic compounds arise only in organisms was disproved when chemists synthesized these compounds

323

Mechanism

is the view that all natural phenomena are governed by physical and chemical laws

324

Stanley miller proved

a mechanism view

325

Stanley Miller's classic experiment demonstrated the

abiotic synthesis of organic compounds.

326

Electron configuration is the key to an atom's

characteristics

327

electron configuration determines

the kinds and number of bonds an atom will form with other atoms

328

Carbon can make

4 covalent bonds

329

hydrogen has

a valence of 1

330

oxygen has

a valence of 2

331

nitrogen has

a valence of 3

332

carbon has

a valence of 4

333

carbon atoms can partner with atoms other than

hydrogen

334

carbon can make

ALOT of different shapes

335

hydrocarbons are

organic molecules consisting of only carbon and hydrogen

336

hydrocarbons are

hydrophobic.
most of their bonds are nonpolar covalent carbon to hydrogen linkages

337

water likes things with

charges

338

water doesnt like

hydrophobic bonds

339

isomers are

compounds with the same molecular formula but different structures and properties

340

structural isomers

have same molecular formulas, but different shapes.
same number of like carbons and hydrogens or something.
they have different covalent arrangements of their atoms.

341

cis-trans isomers

have double bonds. have the same covalent bonds but differ in spatial arrangements.

342

cis isomer=

two X's on same side

343

trans isomer=

the two X's are on opposite sides

344

enantiomers

are isomers that are mirror images of each other

345

enantiomers are important in the

pharmaceutical industry.
two enantiomers of a drug may have different effects.

346

functional groups are

the components of organic molecules that are most commonly involved in chemical reactions

347

the number and arrangement of functional groups give

each molecule its unique properties.

348

functional groups give molecules their

very important qualities

349

the seven functional groups that are most important in the chemistry of life

hydroxyl group
carbonyl group
carboxyl group
amino group
sulfhydryl group
phosphate group
methyl group.

350

all of the seven functional groups are

hydrophilic thus increasing the solubility of organic compounds in water

351

hydroxyl

-OH
alcohols
polar

352

carbonyl

-C=O
aldehyde, ketone
isomers

353

Carboxyl

C=O
I
OH

carboxylic acid
acid

354

amino

NH2 N-H
I
H
amine
base

355

sulfhydryl

-SH
thiol
Crosslink proteins

356

phosphate

O
II
O-P-O-
I
O-

organic phosphates
energy


357

methyl

H
I
C-H
I
H

methylated compounds
DNA (turns off DNA, controls DNA. important)

358

matter is made up of

elements

359

an element is

a substance that cannot be broken down to other substances by chemical reactions.

C, N, Na

360

a compound is

a substance consisting of two or more elements in a fixed ratio

NaCl, H2O.

361

a compound has characteristics different from those of its

elements

362

Carbon, Hydrogen, Oxygen, and nitrogen make up about

96% of living matter

363

most of the remaining 4% consists of

calcium, phosphorus, potassium, and sulfur

364

an atom is

the smallest unit of matter that still retains the properties of an element

365

an element consists of

unique atoms

366

atoms are composed of

subatomic particles

367

isotopes

are two atoms of an element that differ in number of neutrons

368

the chemical behavior of an atom is determined by

the distribution of electrons in electron shells

369

atomic #

number of protons

370

mass #

number of protons + neutrons

371

atomic mass

weight
p + n + e

372

the mass number is written as a

superscript to the left of an elements symbol

373

the atomic number is written as a

subscript to the left of an elements symbol

374

valence electrons

are electrons in the outermost shell or valence shell

375

the valence

of an element is how many electrons it still wants/ needs to fill up the shell

376

covalent bonds

strong and share.
is the sharing of a pair of valence electrons by two atoms.

377

in a covalent bond,

the shared electrons count as part of each atom's valence shell

378

a molecule consists of

two or more atoms held together by covalent bonds

379

a single covalent bond or single bond is

the sharing of one pair of valence electrons

380

a double covalent bond or double bond is

the sharing of two pairs of valence electrons

381

electronegativity is

an atom's attraction for the electrons in a covalent bond

382

the more electronegative an atom,

the more strongly it pulls shared electrons toward itself

383

non-polar covalent bonds

share electrons equally

384

polar covalent bonds

do not share electrons equally.
one atom is more electronegative.

385

unequal sharing of electrons causes a

partial positive or negative charge for each atom or molecule

386

ionic bonds

weaker and transfer electrons.