Question 1

In living systems, a critical component of many reactions is

Accepted Answer

A) carbon dioxide. 
B) calcium. 
C) water. 
D) hydrogen sulfide. 
A) carbon dioxide. 
B) calcium. 
C) water. 
D) hydrogen sulfide. C

Question 2

Which of the following amino acids begins the construction of all proteins in the human body?

Accepted Answer

A) methionine 
B) leucine 
C) proline 
D) tryptophan 
A) methionine 
B) leucine 
C) proline 
D) tryptophan A

Question 3

Which of the following factors explains carbon's prominence in living systems?

Accepted Answer

A) Carbon forms weak reversible bonds. 
B) Carbon bonds with up to three other atoms. 
C) Carbon-based molecules can form long chains and rings. 
D) Carbon does not form small molecules. 
A) Carbon forms weak reversible bonds. 
B) Carbon bonds with up to three other atoms. 
C) Carbon-based molecules can form long chains and rings. 
D) Carbon does not form small molecules. C

Question 4

A carwash attendant offers to treat your windshield with a protective agent. This substance coats the glass, causing beads of water to easily roll off during a rain shower. Which of the following must be correct about the protective agent?

Accepted Answer

A) It resists temperature changes well. 
B) It must be an acid. 
C) It is a polar substance. 
D) It must be hydrophobic. 
A) It resists temperature changes well. 
B) It must be an acid. 
C) It is a polar substance. 
D) It must be hydrophobic.

Question 5

Which of the following is an organic compound?

Accepted Answer

A) water (H₂O) 
B) methane (CH4) 
C) ammonia (NH3) 
D) carbon dioxide (CO₂) 
A) water (H₂O) 
B) methane (CH4) 
C) ammonia (NH3) 
D) carbon dioxide (CO₂)

Question 6

Antibodies are an important class of human proteins that function in immune defense. If scientists fragmented antibodies under laboratory conditions, what chemical building blocks would they recover?

Accepted Answer

A) monosaccharides 
B) phospholipids 
C) amino acids 
D) nitrogenous bases 
A) monosaccharides 
B) phospholipids 
C) amino acids 
D) nitrogenous bases

Question 7

A scientist observed a chemical that changes to bright red in the presence of organic compounds containing nitrogen and phosphorus. To test this chemical, a set of test tubes each containing a purified sample of one of the following organic compounds is prepared. The chemical is then added to each tube. Which test tube will always turn bright red?

Accepted Answer

A) the tube containing nucleic acids 
B) the tube containing proteins 
C) the tube containing carbohydrates 
D) the tube containing phospholipids 
A) the tube containing nucleic acids 
B) the tube containing proteins 
C) the tube containing carbohydrates 
D) the tube containing phospholipids

Question 8

Oil and water do not mix together well because

Accepted Answer

A) water is polar and oil is nonpolar. 
B) only identical molecules of the same chemical can easily mix together. 
C) water has hydrogen bonds and oil is polar. 
D) water and oil are covalently bonded together. 
A) water is polar and oil is nonpolar. 
B) only identical molecules of the same chemical can easily mix together. 
C) water has hydrogen bonds and oil is polar. 
D) water and oil are covalently bonded together.

Question 9

Which of the following pieces of evidence would best demonstrate that a bacterium found on an asteroid originated in outer space?

Accepted Answer

A) the presence of volcanic ash on the outside of the bacterial cell 
B) the absence of common gases found in Earth's atmosphere 
C) the presence of right-handed amino acids in the bacterium's proteins 
D) the absence of hydrogen bonds between water molecules in the bacterial cell 
A) the presence of volcanic ash on the outside of the bacterial cell 
B) the absence of common gases found in Earth's atmosphere 
C) the presence of right-handed amino acids in the bacterium's proteins 
D) the absence of hydrogen bonds between water molecules in the bacterial cell

Question 10

The pH scale measures

Accepted Answer

A) the amount of water in a solution. 
B) the likelihood that a solution will evaporate. 
C) the concentration of hydrogen ions in a solution. 
D) the number of atoms found within a molecule. 
A) the amount of water in a solution. 
B) the likelihood that a solution will evaporate. 
C) the concentration of hydrogen ions in a solution. 
D) the number of atoms found within a molecule.

Question 11

Using the answer choices below (a through d), match the characteristic with its macromolecule class.
-form the major framework of biological membranes

Accepted Answer

A) lipids 
B) carbohydrates 
C) nucleic acids 
D) proteins 
A) lipids 
B) carbohydrates 
C) nucleic acids 
D) proteins

Question 12

Which of the following could be built solely from glucose molecules?

Accepted Answer

A) fatty acids 
B) DNA 
C) oils 
D) starch 
A) fatty acids 
B) DNA 
C) oils 
D) starch

Question 13

How many different amino acids are used to build proteins?

Accepted Answer

A) 90 
B) 20 
C) 19 
D) 4 
A) 90 
B) 20 
C) 19 
D) 4

Question 14

The central element found in organic molecules is

Accepted Answer

A) calcium. 
B) carbon. 
C) silicon. 
D) sodium. 
A) calcium. 
B) carbon. 
C) silicon. 
D) sodium.

Question 15

Chemists often represent the structure of atoms using p, n, and e to indicate the number of protons, neutrons, and electrons. Which atom would have an atomic weight of 30?

Accepted Answer

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

Question 16

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

Accepted Answer

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

Question 17

Using the answer choices below (a through d), match the characteristic with its macromolecule class.
-store and transmit genetic information

Accepted Answer

A) lipids 
B) carbohydrates 
C) nucleic acids 
D) proteins 
A) lipids 
B) carbohydrates 
C) nucleic acids 
D) proteins

Question 18

Nucleotides

Accepted Answer

A) are the building blocks of proteins. 
B) are involved in every chemical reaction in the cell. 
C) form physical structures such as hair. 
D) are the building blocks of nucleic acids. 
A) are the building blocks of proteins. 
B) are involved in every chemical reaction in the cell. 
C) form physical structures such as hair. 
D) are the building blocks of nucleic acids.

Question 19

For each of the major classes of macromolecules, indicate the basic subunits used to build it.

Accepted Answer

Carbohydrates are composed of monomers c

Question 20

If iodide ions (I⁻) were dissolved in water, they would be attracted to

Accepted Answer

A) A only 
B) B only 
C) C only 
D) A and C 
A) A only 
B) B only 
C) C only 
D) A and C

Exam 2: Chemistry of Life

In living systems, a critical component of many reactions is

Which of the following amino acids begins the construction of all proteins in the human body?

Which of the following factors explains carbon's prominence in living systems?

A carwash attendant offers to treat your windshield with a protective agent. This substance coats the glass, causing beads of water to easily roll off during a rain shower. Which of the following must be correct about the protective agent?

Which of the following is an organic compound?

Antibodies are an important class of human proteins that function in immune defense. If scientists fragmented antibodies under laboratory conditions, what chemical building blocks would they recover?

Oil and water do not mix together well because

Which of the following pieces of evidence would best demonstrate that a bacterium found on an asteroid originated in outer space?

The pH scale measures

Using the answer choices below (a through d), match the characteristic with its macromolecule class. -form the major framework of biological membranes

Which of the following could be built solely from glucose molecules?

How many different amino acids are used to build proteins?

The central element found in organic molecules is

Chemists often represent the structure of atoms using p, n, and e to indicate the number of protons, neutrons, and electrons. Which atom would have an atomic weight of 30?

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

Using the answer choices below (a through d), match the characteristic with its macromolecule class. -store and transmit genetic information

Nucleotides

For each of the major classes of macromolecules, indicate the basic subunits used to build it.

If iodide ions (I⁻) were dissolved in water, they would be attracted to

The Nature of Science

Life Is Cellular

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Cell Division

Patterns of Inheritance

Chromosomes and Human Genetics

What Genes Are

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Evidence for Evolution

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General Principles of Ecology

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