Biology Chapter 4

When three phosphate groups are covalently attached to adenosine, __________ is formed. ATP ADP AMP Pi glycerol phosphate

ATP

Which hydrocarbon has a double bond in its carbon skeleton?

C2H4

Which of the following is a hydrocarbon? C6H12O6 CO2 C3H8 CCl2F2 H2CO3

C3H8 (This is a typical hydrocarbon with single covalent bonds; the number of hydrogen atoms is equal to two times the number of carbon atoms plus 2.)

Although the structures of the functional groups that are most important to life vary, they share one thing in common: They __________. all help give each biological molecule its unique properties all contain oxygen all have at least one double bond always cause the carbon to which they are attached to become an asymmetric carbon, thus converting the molecule into an enantiomer force straight chains of carbons into closed rings of carbon

all help give each biological molecule its unique properties

A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different cis-trans isomers exist for this molecule? none two four six

two

Biologically important chemical groups include all of the following except __________. water (H2O) carboxyl group (-COOH) amine group (-NH2) sulfhydryl group (-SH) phosphate group (-PO3-2)

water (H2O)

Carbon's atomic number is 6. This means that it has __________ electrons. After completing the first energy level, carbon has __________ valence electrons and can form __________ bonds. 6; 4; 4 4; 4; 4 6; 2; 2 12; 6; 6 12; 4; 4

6; 4; 4

This molecule contains five carbons in a row, labeled a-e. Carbon has one hydrogen atom and one double bond to oxygen. Carbon b has one hydrogen atom and one OH group. Carbons c and d have two hydrogen atoms each. Carbon e has three hydrogen atoms.

B

Which of the following is found in all amino acids?

Both -COOH and -NHv2

Which of the following is an organic molecule? CH4 O2 NaCl Ne

CH4

The carbon skeleton can vary in all of the following except __________.

Lacking hydrogen atoms

The chemical group that is involved in regulating DNA is the __________. methyl group (-CH3) carboxyl group (-COOH) amine group (-NH2) sulfhydryl group (-SH) phosphate group (-PO3-2)

Methyl group (-CH3)

Which of these is a thiol? —COH —SH —OH None of the listed responses is correct.

NONE OF THE LISTED RESPONSES IS CORRECT

Which of the following molecules is a weak acid? R—NH2 R—SH R—OH R—COOH

R—COOH (The carboxyl group (—COOH) of R—COOH can donate a proton (H+).

Which of the following molecules is a weak base? R—OH R—SH R—NH2 None of the listed responses is correct.

R—NH2

Which functional group is not present in this molecule?

Sulfhydryl

Which of the following examples best describes a unique functional property of the carboxyl group? Its compounds may be structural isomers with different properties. Two carboxyl groups can bond covalently to help stabilize protein structure. It is polar as a result of the electronegative oxygen atom drawing electrons toward it. The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.

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

Which of the following molecules has a carboxyl functional group? R—NH2 R—OPO3-2 R—COH R—COOH

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

Which of the molecules shown in question 5 has an asymmetric carbon? Which carbon is asymmetric?

The molecule on the right; the middle carbon is asymmetric.

Choose the pair of terms that completes this sentence about functional groups in organic chemistry: Carboxyl is to __________ as __________ is to base. acid; amino acid; carbonyl sulfhydryl; carbonyl hydroxyl; amino ketone; phosphate

acid; amino

What functional group is commonly used in cells to transfer energy from one organic molecule to another? sulfhydryl carboxyl amino hydroxyl phosphate

phosphate

Which of the following functional groups is present in all amino acids? —SH —COH —NH2 —OH

—NH2

The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules. nitrogen oxygen sulfur carbon

carbon

The two compounds are related to each other by being __________. isomers hydrocarbons organic compounds hydrocarbons, isomers, organic compounds, and double-bonded compounds

hydrocarbons, isomers, organic compounds, and double-bonded compounds

Most organic compounds contain carbon and _____. nitrogen sulfur oxygen hydrogen phosphate

hydrogen

Which of the following are properties of hydrocarbons? hydrophilic, containing numerous carboxyl groups, nonpolar hydrophilic, good source of stored energy, consisting primarily of carbon and hydrogen hydrophobic, polar, charged hydrophobic, nonpolar, good source of stored energy

hydrophobic, nonpolar, good source of stored energy

Which of the following groups is capable of hydrogen bonding with an oxygen atom on another functional group? hydroxyl group carboxyl group amino group All of the listed responses are correct.

hydroxyl group carboxyl group amino group

Inorganic carbon such as CO2 differs from organic carbon because __________. organic carbon always has a hydrogen atom covalently attached to it inorganic carbon always has double bonds and organic carbon never has double bonds inorganic carbon always has a hydrogen atom covalently attached to it CO2 is an example of an organic molecule

organic carbon always has a hydrogen atom covalently attached to it

The experiments of Wöhler, Kolbe, Miller, and other chemists invalidated the concept of vitalism by demonstrating that _____. tissues extracted from living organisms could still promote organic reactions carbon atoms were common in both living organisms and nonliving substances such as rocks and soil complex organic substances are the result of a series of sequential synthetic reactions occurring in both living organisms and nonliving systems one organic substance could be transformed into another organic substance organic molecules could be produced apart from living organisms using inorganic materials

organic molecules could be produced apart from living organisms using inorganic material

A straight-chain carbon compound constructed from __________ must contain at least one carbon-carbon double bond. 8 hydrogen atoms, 3 carbon atoms, and 3 oxygen atoms 6 hydrogen atoms and 2 carbon atoms 6 hydrogen atoms and 3 carbon atoms 6 hydrogen atoms, 2 carbon atoms, and 1 oxygen atom

6 hydrogen atoms and 3 carbon atoms (There must be a carbon-carbon double bond for this molecule to exist.)

What is ATP's importance in the cell? ATP can add phosphate groups, thereby releasing energy that can be used in cellular processes. ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes. ATP contains a long hydrocarbon tail and is important in storing energy. ATP stores energy in carbonyl groups. When a carbonyl group is removed, energy is released to be used in cellular processes.

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

Which element is always associated with organic chemistry?

Carbon

Which element is always associated with organic chemistry? Carbon Sulfur Nitrogen Hydrogen Oxygen

Carbon

What is the reason carbon atoms are the most versatile building blocks of the molecules used by living organisms? Each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions. Carbon is the central atom in urea, a molecule used by many living organisms to transport wastes from the body. Carbon is the central atom of carbon dioxide, a necessary molecule for photosynthesis. All of the listed responses are correct.

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

Pharmaceutical companies are selling billions of dollars' worth of single- enantiomer drugs. Why might it be important to use only one form of an enantiomer? It is cheaper to manufacture only one of the enantiomers. It is not important. Both enantiomers will be equally effective. One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic. The left-handed version of the enantiomer is always the effective one.

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

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 two isomers of the drug contain different functional groups and the isomer with the aberrant functional group is connected to the fatalities. The asymmetrical carbon causes the solubility of the two drug isomers to vary significantly, thus having different chemical properties and effects on people who take them. The isomers are enantiomers, with one having toxic effects on humans. The double bond involving the asymmetrical carbon can generate cis-trans isomers that typically have different chemical properties, thus accounting for the drug's toxic properties.

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

Which of the following best describes cis-trans isomers? They differ in the arrangement of covalent bonds and in covalent partners. They are long chains of hydrogen and carbon atoms. They have the same number of atoms of the same elements but different structures. They differ in their spatial arrangement around inflexible double bonds. They are mirror images of each other.

They differ in their spatial arrangement around inflexible double bonds.

The carbon atom is tetravalent, which means that __________. carbon's first electron shell holds four electrons the bond angle between each bond is 90°, forming an arrangement like the points on a compass a carbon atom can complete its valence shell by forming four covalent bonds carbon readily forms ionic bonds

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

The carbon atom is tetravalent; this means that __________.

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

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 flat sheet with carbon in the center a tetrahedron with carbon in the center a triangle with carbon in the center All of the listed responses are possible.

a tetrahedron with carbon in the center

Stanley Miller's experiments were significant because he demonstrated that __________. organic molecules can be synthesized only by living organisms a variety of simple organic compounds could be spontaneously synthesized from components in Earth's primitive atmosphere the behavior of any molecule containing a carbon atom was fundamentally the same lightning discharges could produce the molecules previously presumed to have originated in volcanic outgassings

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

In Miller's 1953 laboratory experiment, __________. abiotic compounds cycled through the apparatus and were sampled for organic compounds organic compounds were added to the seawater and decomposed condensed molecules never contained organic compounds the experiment was not useful in supporting evolution the atmosphere in the experiment contained O2

abiotic compounds cycled through the apparatus and were sampled for organic compounds

Which chemical group is most likely to be responsible for an organic molecule behaving as a base? Amino Hydroxyl Carbonyl Carboxyl Phosphate

amino

Which of these is found in all amino acids? —OH —COH —COOH both —COOH and —NH2

both —COOH and —NH2 ( 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.)

Molecules that contain only carbon and hydrogen are __________. called hydrocarbons called hydrated carbons called inorganic carbons found only as linear chains

called hydrocarbons

What are the six most important chemical elements of life? carbon, nitrogen, sulfur, hydrogen, iron, magnesium carbon, nitrogen, oxygen, calcium, phosphate, hydrogen carbon, nitrogen, calcium, oxygen, phosphate, iron carbon, nitrogen, oxygen, hydrogen, phosphate, sulfur

carbon, nitrogen, oxygen, hydrogen, phosphate, sulfur

Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule such as citric acid to be acidic? carbonyl carboxyl hydrocarbon amino hydroxy

carboxyl

Which functional group would you predict is part of abscisic acid? hydroxyl group carbonyl group carboxyl group amino group

carboxyl group (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.)

The chemical group that acts as an acid is the __________. carboxyl group (-COOH) amine group (-NH2) sulfhydryl group (-SH) phosphate group (-PO3-2) methyl group (-CH3)

carboxyl group (-COOH)

When a double bond joins two carbon atoms, __________ can form.

cis-trans isomers

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 classic experiment described in the text. This reanalysis did which of the following? revealed the formation of the same amino acids that Miller initially observed but in a more purified form contradicted Miller's earlier experimental results and provided more support for an undefined life force as the way organic molecules are made in nature greatly expanded Miller's earlier findings by uncovering the traces of cell-like entities being formed in the volcano simulation experiments identified additional organic compounds that had not been found by Miller

identified additional organic compounds that had not been found by Miller

Molecules that have the same chemical formula (same numbers of each atom) but different three-dimensional shapes are called _____. functional groups isomers hydrocarbons isotopes enantiomers

isomers

The carbon skeleton can vary in all of the following except __________. lacking hydrogen atoms length branching double bond position presence of rings

lacking hydrogen atoms

In the pharmaceutical industry, two enantiomers of a drug __________. may not be equally effective are always produced as a mixture are equally effective never counteract each other are equally safe in either form

may not be equally effective

Enantiomers are __________. mirror-image isomers of a molecule structural isomers of a molecule cis-trans isomers of a molecule molecules that can be tightly packed because they are unsaturated not important in drug development

mirror-image isomers of a molecule

Vitalism gave way to mechanism, the view that _____ carbon's ability to form four covalent bonds makes complex molecules possible there was a life force outside the jurisdiction of physical and chemical laws physical and chemical laws govern living systems life on Earth began by way of abiotic synthesis of organic compounds bond angles are unpredictable

physical and chemical laws govern living systems

Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they __________. share the same functional group: a hydroxyl are soluble in water all contain a carbonyl group are hydrophobic

share the same functional group: a hydroxyl

Both sugars contain three carbon atoms. The first sugar has an OH group on both the first and third carbons, and one double bond to oxygen on the second carbon. The second sugar has one double bond to oxygen on the first carbon and an OH group on both the second and third carbons.

structural isomers

This molecule contains three carbon atoms. The first is the carbon of a CO2H group, the second has an NH2 group on it, and the third is linked to an OH group. There is also one hydrogen attached to the second carbon and two hydrogens attached to the third carbon.

sulfhydryl

The chemical group that helps stabilize protein structure is the __________. sulfhydryl group (-SH) amine group (-NH2) carboxyl group (-COOH) phosphate group (-PO3-2) methyl group (-CH3)

sulfhydryl group (-SH)

Variations in the reactive properties of different organic molecules are most closely associated with _____. the number of carbon atoms comprising the molecule's skeleton the orientation of the carbon skeleton, as either ringed or linear the presence or absence of double bonds the number of asymmetric carbon atoms present the presence or absence of functional groups

the presence or absence of functional groups

Which action could produce a carbonyl group?

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

Structural isomers have __________. the same molecular formula but different covalent arrangements of their carbon skeletons a different molecular formula and the same covalent arrangement of their carbon skeletons the same molecular formula and the same covalent arrangement of their carbon skeletons different functional groups left- and right-handed forms

the same molecular formula but different covalent arrangements of their carbon skeletons

Organic chemistry is currently defined as

the study of carbon compounds.

Chemical groups are significant because __________. they contribute to the molecular shape of a molecule and its unique properties they are always the same and do not influence the properties of a molecule they can never be substituted they stabilize a molecule by preventing chemical reactions

they contribute to the molecular shape of a molecule and its unique properties

Which of the following functional groups increases the solubility of organic compounds in water? —COH —OH —COOH All of the listed responses are correct.

—COOH —COH —OH