Question 1

_______ molecules are nonpolar molecules that are repelled by water.

Accepted Answer

The answer of _______ molecules are nonpolar molecules that are...

Question 2

Ionic bonds

Accepted Answer

A)  result from the sharing of electrons between atoms. 
B)  form only between polar molecules. 
C)  form between atoms that develop opposite charges. 
D)  are due to protons repelling each other. 
A)  result from the sharing of electrons between atoms. 
B)  form only between polar molecules. 
C)  form between atoms that develop opposite charges. 
D)  are due to protons repelling each other.

Question 3

The smallest unit of a chemical element that still has the properties of that element is a(n)

Accepted Answer

A)  amino acid. 
B)  molecule. 
C)  atom. 
D)  bond. 
A)  amino acid. 
B)  molecule. 
C)  atom. 
D)  bond.

Question 4

The primary structure of a protein consists of its amino acid sequence.

Accepted Answer

A) True 
 B)False

Question 5

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

Accepted Answer

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

Question 6

A solution with a pH of 3 is

Accepted Answer

A)  acidic. 
B)  nonpolar. 
C)  basic. 
D)  neutral. 
A)  acidic. 
B)  nonpolar. 
C)  basic. 
D)  neutral.

Question 7

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

Accepted Answer

A) True 
 B)False

Question 8

Which of the following is not a role of fatty acids in living organisms?

Accepted Answer

A)  energy storage 
B)  storage of genetic information 
C)  membrane construction 
D)  building blocks of fats 
A)  energy storage 
B)  storage of genetic information 
C)  membrane construction 
D)  building blocks of fats

Question 9

The carbon dioxide you breath out is carried to the lungs in the blood. Carbon dioxide, when dissolved in a liquid, is an acid. How does the body prevent your blood from becoming too acidic on the way to your lungs?

Accepted Answer

A)  Buffers in the blood release OH- ions to make the blood more basic. 
B)  Buffers in the blood accept H+ ions to make the blood less acidic. 
C)  Buffers in the blood release H+ to make the blood more basic. 
D)  Buffers in the blood accept OH- to make the blood less acidic. 
A)  Buffers in the blood release OH- ions to make the blood more basic. 
B)  Buffers in the blood accept H+ ions to make the blood less acidic. 
C)  Buffers in the blood release H+ to make the blood more basic. 
D)  Buffers in the blood accept OH- to make the blood less acidic.

Question 10

We use soap to clean ourselves better than we could with water alone. Soaps contain phospholipids which 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 11

Cholesterol is commonly found in the cell membranes of warm-blooded animals because

Accepted Answer

A)  excess dietary cholesterol is stored in cell membranes. 
B)  cholesterol is involved in the muscle contractions needed to move an animal around its environment. 
C)  it prevents the cell membrane from becoming too runny at body temperature. 
D)  warm-blooded animals tend to consume large amounts of cholesterol-rich foods. 
A)  excess dietary cholesterol is stored in cell membranes. 
B)  cholesterol is involved in the muscle contractions needed to move an animal around its environment. 
C)  it prevents the cell membrane from becoming too runny at body temperature. 
D)  warm-blooded animals tend to consume large amounts of cholesterol-rich foods.

Question 12

You purchase a laundry product that claims to use natural enzymes to remove stains from clothing. After spilling grape juice on your favorite shirt, you apply the product and wash your shirt (following the directions, of course). When you pull the shirt out of the washer, the stain is still there! Which of the following might explain why the stain remover did not work?

Accepted Answer

A)  The stain remover and the grape juice are both hydrophilic, so the enzymes could not interact with the stain. 
B)  The pH of the water in your house is too basic or acidic for the enzymes to work properly. 
C)  Before you got home from the store, you stopped at the mall and left your stain remover in the trunk of your car on a hot day, denaturing the enzymes. 
D)  Both B and C are possible explanations. 
A)  The stain remover and the grape juice are both hydrophilic, so the enzymes could not interact with the stain. 
B)  The pH of the water in your house is too basic or acidic for the enzymes to work properly. 
C)  Before you got home from the store, you stopped at the mall and left your stain remover in the trunk of your car on a hot day, denaturing the enzymes. 
D)  Both B and C are possible explanations.

Question 13

Pure water has a pH of 7. The inside of a cell is also about pH 7. This might be so because

Accepted Answer

A)  buffers work best when the pH is close to 7. 
B)  humans are largely made up of water by weight. 
C)  most of the chemical reactions that occur in humans can proceed optimally at pH 7. 
D)  ionic bonds cannot form at pH 7. 
A)  buffers work best when the pH is close to 7. 
B)  humans are largely made up of water by weight. 
C)  most of the chemical reactions that occur in humans can proceed optimally at pH 7. 
D)  ionic bonds cannot form at pH 7.

Question 14

You are given an unknown substance and asked to determine whether it is polar or nonpolar. The easiest way to do this would be to

Accepted Answer

A)  determine whether the compound is held together by hydrogen bonds. 
B)  determine the number of electrons in the compound's outer shell. 
C)  mix the compound with an ionic substance to see whether its bonds can withstand the pressure. 
D)  determine whether the compound dissolves in water. 
A)  determine whether the compound is held together by hydrogen bonds. 
B)  determine the number of electrons in the compound's outer shell. 
C)  mix the compound with an ionic substance to see whether its bonds can withstand the pressure. 
D)  determine whether the compound dissolves in water.

Question 15

Molecules with an uneven distribution of charge are described as _______.

Accepted Answer

The answer of Molecules with an uneven distribution of charge...

Question 16

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)  0 
B)  1 
C)  3 
D)  8 
A)  0 
B)  1 
C)  3 
D)  8

Question 17

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 group. 
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 group. 
C)  hydrogen bonds between the bases of two of these molecules. 
D)  ionic bonds between the molecule's sugar and base.

Question 18

One of the symptoms of kidney disease is the presence of proteins in a patient's urine. To quickly test for kidney disease using a urine sample, a doctor might add a chemical that causes a color change when

Accepted Answer

A)  nitrogen, but not oxygen, is present. 
B)  nitrogen, but not phosphorus, is present. 
C)  only oxygen and hydrogen are present. 
D)  only carbon and hydrogen are present. 
A)  nitrogen, but not oxygen, is present. 
B)  nitrogen, but not phosphorus, is present. 
C)  only oxygen and hydrogen are present. 
D)  only carbon and hydrogen are present.

Question 19

All the isotopes of a particular element have the same number of protons.

Accepted Answer

A) True 
 B)False

Question 20

Of the following which indicates the most basic pH?

Accepted Answer

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

Exam 4: Chemical Building Blocks

_______ molecules are nonpolar molecules that are repelled by water.

Ionic bonds

The smallest unit of a chemical element that still has the properties of that element is a(n)

The primary structure of a protein consists of its amino acid sequence.

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

A solution with a pH of 3 is

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

Which of the following is not a role of fatty acids in living organisms?

The carbon dioxide you breath out is carried to the lungs in the blood. Carbon dioxide, when dissolved in a liquid, is an acid. How does the body prevent your blood from becoming too acidic on the way to your lungs?

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

Cholesterol is commonly found in the cell membranes of warm-blooded animals because

Pure water has a pH of 7. The inside of a cell is also about pH 7. This might be so because

You are given an unknown substance and asked to determine whether it is polar or nonpolar. The easiest way to do this would be to

Molecules with an uneven distribution of charge are described as _______.

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.

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

One of the symptoms of kidney disease is the presence of proteins in a patient's urine. To quickly test for kidney disease using a urine sample, a doctor might add a chemical that causes a color change when

All the isotopes of a particular element have the same number of protons.

Of the following which indicates the most basic pH?

The Nature of Science and the Characteristics of Life

Organizing the Diversity of Life

Major Groups of Living Organisms

Cell Structure and Internal Compartments

Cell Membranes, Transport, and Communication

Energy and Enzymes

Photosynthesis and Cellular Respiration

Cell Division

Patterns of Inheritance

Chromosomes and Human Genetics

DNA

From Gene to Protein

Control of Gene Expression

DNA Technology

How Evolution Works

Evolution of Populations

Adaptation and Speciation

The Evolutionary History of Life

Maintaining the Internal Environment

Animal Nutrition and Digestion

Gas Exchange

The Circulatory System

Animal Hormones

The Nervous System

Sensing the Environment

Skeletons, Muscles, and Movement

Defenses against Disease

Reproduction and Development

Animal Behavior

Plant Structure, Nutrition, and Transport

Plant Growth and Reproduction

The Biosphere

Growth of Populations

Interactions among Organisms

Communities of Organisms

Ecosystems

Global Change

Biodiversity and People

Cancer: Cell Division Out of Control

Harnessing the Human Genome

Humans and Evolution

Smoking--Beyond Lung Cancer

Feeding a Hungry Planet

Building a Sustainable Society

Filters