Question 1

The outer electron shell of a nitrogen atom can hold up to eight electrons but contains only five.As a result,nitrogen can form ________ covalent bonds.

Accepted Answer

A)  Zero 
B)  One 
C)  Three 
D)  Eight 
A)  Zero 
B)  One 
C)  Three 
D)  Eight

Question 2

The monomers in proteins are ________.

Accepted Answer

The answer of The monomers in proteins are ________....

Question 3

Of the following pH values,which indicates the most basic pH?

Accepted Answer

A)  3 
B)  7 
C)  8 
D)  10 
A)  3 
B)  7 
C)  8 
D)  10

Question 4

Proteins provide most of the energy for life processes.

Accepted Answer

A) True 
 B)False

Question 5

The sugar glucose has an important role

Accepted Answer

A)  in the formation of proteins. 
B)  in short-term energy storage. 
C)  in the formation of membranes. 
D)  as a building block of nucleotides. 
A)  in the formation of proteins. 
B)  in short-term energy storage. 
C)  in the formation of membranes. 
D)  as a building block of nucleotides.

Question 6

In the following illustration,a positive ion is surrounded by water molecules.
 
The water molecules orient as shown because the slightly ________ atoms in the water molecules are attracted to the positive charge of the ion.

Accepted Answer

A)  negative hydrogen 
B)  positive hydrogen 
C)  negative oxygen 
D)  positive oxygen 
A)  negative hydrogen 
B)  positive hydrogen 
C)  negative oxygen 
D)  positive oxygen

Question 7

Nonpolar molecules are highly charged.

Accepted Answer

A) True 
 B)False

Question 8

The process of partial hydrogenation turns liquid plant lipids into semisolid lipids by

Accepted Answer

A)  adding antioxidants that prevent lipid oxidation. 
B)  creating hydrocarbon chains that are more kinked than those in natural fats. 
C)  substituting nitrogen for carbon in fatty acid chains. 
D)  removing double bonds and adding hydrogen to the fatty acid chains of plant lipids. 
A)  adding antioxidants that prevent lipid oxidation. 
B)  creating hydrocarbon chains that are more kinked than those in natural fats. 
C)  substituting nitrogen for carbon in fatty acid chains. 
D)  removing double bonds and adding hydrogen to the fatty acid chains of plant lipids.

Question 9

Chemical reactions do not change the identity of the participating atoms;all atoms present at the beginning of the reaction must be present at the end.Balance the chemical reaction by indicating the number of molecules necessary for each reactant and product: ________ Cl2 +________ NaBr $\rarr$_______ Br2 + ________ NaCl.

Accepted Answer

A)  1;1;1;1 
B)  1;2;1;1 
C)  1;2;1;2 
D)  2;2;1;2 
A)  1;1;1;1 
B)  1;2;1;1 
C)  1;2;1;2 
D)  2;2;1;2

Question 10

In water,phospholipids arrange themselves such that

Accepted Answer

A)  their fatty acid head groups are facing the water. 
B)  their hydrophobic tails are kept away from the water. 
C)  saturated fatty acids face the water,while unsaturated fatty acids are separated from the water. 
D)  the charged atoms on their fatty acid chains can interact directly with the water molecules. 
A)  their fatty acid head groups are facing the water. 
B)  their hydrophobic tails are kept away from the water. 
C)  saturated fatty acids face the water,while unsaturated fatty acids are separated from the water. 
D)  the charged atoms on their fatty acid chains can interact directly with the water molecules.

Question 11

Chemists often represent the structure of atoms using p,n,and e to indicate the numbers of protons,neutrons,and electrons;which atom would have an atomic mass number of 30?

Accepted Answer

A)  10 p,10 n,10 e 
B)  15 p,15 n,15 e 
C)  15 p,0 n,15 e 
D)  0 p,15 n,15 e 
A)  10 p,10 n,10 e 
B)  15 p,15 n,15 e 
C)  15 p,0 n,15 e 
D)  0 p,15 n,15 e

Question 12

When you place a piece of red meat on a hot barbeque,it slowly changes from soft to firm.Meat is primarily made of proteins.Which of the following might account for the change in texture during cooking?

Accepted Answer

A)  The heat causes the cells in the meat to produce more protein. 
B)  The heat causes chemical bonds to form between the proteins and nucleic acids in the meat. 
C)  The heat from the barbeque converts proteins into lipids. 
D)  The addition of heat causes proteins to denature and link together. 
A)  The heat causes the cells in the meat to produce more protein. 
B)  The heat causes chemical bonds to form between the proteins and nucleic acids in the meat. 
C)  The heat from the barbeque converts proteins into lipids. 
D)  The addition of heat causes proteins to denature and link together.

Question 13

The following figure shows the structural and space-filling models for stearic acid and oleic acid.
 
Although the two fatty acids have the same number of carbon atoms,they have different three-dimensional configurations;oleic acid has a slight bend near the middle.The result is that

Accepted Answer

A)  a pure sample of oleic acid would be more liquid than a pure sample of stearic acid. 
B)  stearic acid would be classified as an unsaturated fatty acid. 
C)  you would be more likely to find stearic acid in the form of an oil than in the form of a fat. 
D)  oleic acid would be classified a saturated fatty acid. 
A)  a pure sample of oleic acid would be more liquid than a pure sample of stearic acid. 
B)  stearic acid would be classified as an unsaturated fatty acid. 
C)  you would be more likely to find stearic acid in the form of an oil than in the form of a fat. 
D)  oleic acid would be classified a saturated fatty acid.

Question 14

We use soap to clean ourselves better than we could with water alone.Soaps contain phospholipids that are responsible for the cleansing action.Which of the following statements is the most likely explanation for how soaps work?

Accepted Answer

A)  Phospholipids are ions and therefore mix with both the water and oily dirt. 
B)  Phospholipids are completely hydrophilic and,therefore,oily dirt takes the place of the phospholipid molecules that would be dissolved in the rinse water. 
C)  The phospholipid tail attaches to the oily dirt,while the phospholipid head interacts with the rinse water and carries the dirt (and soap)away with it. 
D)  The nonpolar fatty acid chains that make up the heads of the phospholipid are hydrophilic,and thus are repelled by the water. 
A)  Phospholipids are ions and therefore mix with both the water and oily dirt. 
B)  Phospholipids are completely hydrophilic and,therefore,oily dirt takes the place of the phospholipid molecules that would be dissolved in the rinse water. 
C)  The phospholipid tail attaches to the oily dirt,while the phospholipid head interacts with the rinse water and carries the dirt (and soap)away with it. 
D)  The nonpolar fatty acid chains that make up the heads of the phospholipid are hydrophilic,and thus are repelled by the water.

Question 15

Covalent bonds are formed by

Accepted Answer

A)  the sharing of valence electrons. 
B)  the transfer of valence electrons from one atom to another. 
C)  the sharing of electrons in the innermost shell. 
D)  the conversion of ionic bonds to covalent bonds. 
A)  the sharing of valence electrons. 
B)  the transfer of valence electrons from one atom to another. 
C)  the sharing of electrons in the innermost shell. 
D)  the conversion of ionic bonds to covalent bonds.

Question 16

An atom is in its most stable state when all its electron shells are filled to capacity.

Accepted Answer

A) True 
 B)False

Question 17

Molecules that are nonpolar and repelled by water are called ________.

Accepted Answer

The answer of Molecules that are nonpolar and repelled by...

Question 18

The number that represents neutrality on the pH scale is ________.

Accepted Answer

The answer of The number that represents neutrality on the...

Question 19

ATP is a universal fuel for living organisms.The energy that ATP molecules deliver in chemical reactions is stored in

Accepted Answer

A)  covalent bonds between the molecule's phosphate groups. 
B)  covalent bonds between the molecule's sugar and phosphate groups. 
C)  hydrogen bonds between the bases of two of these molecules. 
D)  ionic bonds between the molecule's sugar and base. 
A)  covalent bonds between the molecule's phosphate groups. 
B)  covalent bonds between the molecule's sugar and phosphate groups. 
C)  hydrogen bonds between the bases of two of these molecules. 
D)  ionic bonds between the molecule's sugar and base.

Question 20

Covalent bonds contain ions.

Accepted Answer

A) True 
 B)False

Exam 2: The Chemistry of Life

The outer electron shell of a nitrogen atom can hold up to eight electrons but contains only five.As a result,nitrogen can form ________ covalent bonds.

The monomers in proteins are ________.

Of the following pH values,which indicates the most basic pH?

Proteins provide most of the energy for life processes.

The sugar glucose has an important role

In the following illustration,a positive ion is surrounded by water molecules. The water molecules orient as shown because the slightly ________ atoms in the water molecules are attracted to the positive charge of the ion.

Nonpolar molecules are highly charged.

The process of partial hydrogenation turns liquid plant lipids into semisolid lipids by

In water,phospholipids arrange themselves such that

Chemists often represent the structure of atoms using p,n,and e to indicate the numbers of protons,neutrons,and electrons;which atom would have an atomic mass number of 30?

When you place a piece of red meat on a hot barbeque,it slowly changes from soft to firm.Meat is primarily made of proteins.Which of the following might account for the change in texture during cooking?

The following figure shows the structural and space-filling models for stearic acid and oleic acid. Although the two fatty acids have the same number of carbon atoms,they have different three-dimensional configurations;oleic acid has a slight bend near the middle.The result is that

We use soap to clean ourselves better than we could with water alone.Soaps contain phospholipids that are responsible for the cleansing action.Which of the following statements is the most likely explanation for how soaps work?

Covalent bonds are formed by

An atom is in its most stable state when all its electron shells are filled to capacity.

Molecules that are nonpolar and repelled by water are called ________.

The number that represents neutrality on the pH scale is ________.

ATP is a universal fuel for living organisms.The energy that ATP molecules deliver in chemical reactions is stored in

Covalent bonds contain ions.

The Nature of Science and the Characteristics of Life

Cell Structure and Internal Compartments

Cell Membranes, Transport, and Communication

Energy, Metabolism, and Enzymes

Photosynthesis and Cellular Respiration

Cell Division

Cancer and Human Health

Patterns of Inheritance

Chromosomes and Human Genetics

DNA and Genes

From Gene to Protein

DNA Technology

How Evolution Works

The Origin of Species

The Evolution of Biodiversity

Biological Diversity, Bacteria, and Archaea

Protista, Plantae, and Fungi

Animalia

The Biosphere

Growth of Populations

Animal Behavior

Ecological Communities

Ecosystems

Global Change

Internal Organization and Homeostasis

Nutrition and Digestion

Circulation and Gas Exchange

Animal Hormones

Nervous and Sensory Systems

Skeletons,Muscles,and Movement

The Immune System

Reproduction and Development

Plant Structure, Nutrition, and Transport

Plant Growth and Reproduction

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