Question 1

Phospholipids are found in cell membranes.

Accepted Answer

A) True 
 B)False

Question 2

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 3

The atoms in water molecules are held together by hydrogen bonds.

Accepted Answer

A) True 
 B)False

Question 4

Most living organisms consist of more than 70 percent ________ by weight.

Accepted Answer

The answer of Most living organisms consist of more than...

Question 5

Fevers in young children are a particular concern because oxygen is less effectively transported by hemoglobin at high temperature.How might this be explained?

Accepted Answer

A)  The hemoglobin becomes denatured and cannot transport the oxygen. 
B)  The oxygen becomes denatured and cannot bind to the hemoglobin. 
C)  Oxygen has too much thermal energy to be bound by hemoglobin. 
D)  Oxygen evaporates at high temperature and is not available for binding with hemoglobin. 
A)  The hemoglobin becomes denatured and cannot transport the oxygen. 
B)  The oxygen becomes denatured and cannot bind to the hemoglobin. 
C)  Oxygen has too much thermal energy to be bound by hemoglobin. 
D)  Oxygen evaporates at high temperature and is not available for binding with hemoglobin.

Question 6

In the equation 3H₂ + N₂ à 2NH₃,how many molecules of hydrogen gas (H₂)are present?

Accepted Answer

A)  2 
B)  3 
C)  6 
D)  12 
A)  2 
B)  3 
C)  6 
D)  12

Question 7

Steroids and proteins are different types of lipids.

Accepted Answer

A) True 
 B)False

Question 8

Radioisotopes are useful in scientific research and medicine because they

Accepted Answer

A)  have a different number of protons than other isotopes of the same element. 
B)  give off high-energy radiation that can be detected by film and specialized scanning machines. 
C)  have the same atomic mass as other isotopes of the same element. 
D)  have a different number of electrons than other isotopes of the same element. 
A)  have a different number of protons than other isotopes of the same element. 
B)  give off high-energy radiation that can be detected by film and specialized scanning machines. 
C)  have the same atomic mass as other isotopes of the same element. 
D)  have a different number of electrons than other isotopes of the same element.

Question 9

The types of proteins that speed up the rate of chemical reactions in the cell are called ________.

Accepted Answer

The answer of The types of proteins that speed up...

Question 10

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 11

A molecule with the general formula CH₂O is a(n)

Accepted Answer

A)  protein. 
B)  carbohydrate. 
C)  amino acid. 
D)  nucleic acid. 
A)  protein. 
B)  carbohydrate. 
C)  amino acid. 
D)  nucleic acid.

Question 12

How many hydrogen atoms are in a molecule of C₈H₁₀N₄O₂?

Accepted Answer

A)  8 
B)  10 
C)  20 
D)  24 
A)  8 
B)  10 
C)  20 
D)  24

Question 13

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 14

The number of electrons surrounding an atom's core never changes.

Accepted Answer

A) True 
 B)False

Question 15

A compound that maintains the pH of a solution by taking up or releasing hydrogen ions is called a ________.

Accepted Answer

The answer of A compound that maintains the pH of...

Question 16

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 à________ 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 17

Because both the wood in a tree branch and the spider's exoskeleton are composed of low-density cellulose,each floats when placed in water.

Accepted Answer

A) True 
 B)False

Question 18

A group of monomers bonded together form a ________.

Accepted Answer

The answer of A group of monomers bonded together form...

Question 19

An oil is a lipid that is ________ at room temperature.

Accepted Answer

A)  liquid 
B)  saturated 
C)  supersaturated 
D)  solid 
A)  liquid 
B)  saturated 
C)  supersaturated 
D)  solid

Question 20

O₂,also termed atmospheric oxygen,is considered to be a molecule but not a compound; why not?

Accepted Answer

A)  It contains no covalent bonds. 
B)  It contains a double covalent bond but not a single covalent bond. 
C)  To be considered a compound, there must be a minimum of three atoms; atmospheric oxygen is too small. 
D)  Compounds are defined as molecules constructed from two or more different elements. 
A)  It contains no covalent bonds. 
B)  It contains a double covalent bond but not a single covalent bond. 
C)  To be considered a compound, there must be a minimum of three atoms; atmospheric oxygen is too small. 
D)  Compounds are defined as molecules constructed from two or more different elements.

Exam 2: The Chemistry of Life

Phospholipids are found in cell membranes.

In water,phospholipids arrange themselves such that

The atoms in water molecules are held together by hydrogen bonds.

Most living organisms consist of more than 70 percent ________ by weight.

Fevers in young children are a particular concern because oxygen is less effectively transported by hemoglobin at high temperature.How might this be explained?

In the equation 3H₂ + N₂ à 2NH₃,how many molecules of hydrogen gas (H₂)are present?

Steroids and proteins are different types of lipids.

Radioisotopes are useful in scientific research and medicine because they

The types of proteins that speed up the rate of chemical reactions in the cell are called ________.

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.

A molecule with the general formula CH₂O is a(n)

How many hydrogen atoms are in a molecule of C₈H₁₀N₄O₂?

Covalent bonds are formed by

The number of electrons surrounding an atom's core never changes.

A compound that maintains the pH of a solution by taking up or releasing hydrogen ions is called a ________.

Because both the wood in a tree branch and the spider's exoskeleton are composed of low-density cellulose,each floats when placed in water.

A group of monomers bonded together form a ________.

An oil is a lipid that is ________ at room temperature.

O₂,also termed atmospheric oxygen,is considered to be a molecule but not a compound; why not?

The Nature of Science and the Characteristics of Life

Cell Structure and Internal Compartments

Cell Membranes, Transport, and Communication

Energy, Metabolism, and Enzymes

Photo Synthesis 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

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