Chapter 4

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. A) 6; 4; 4 B) 4; 4; 4 C) 6; 2; 2 D) 12; 6; 6 E) 12; 4; 4

A) 6; 4; 4

What is ATP's importance in the cell? A) ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes. B) ATP contains a long hydrocarbon tail and is important in storing energy. C) ATP can add phosphate groups, thereby releasing energy that can be used in cellular processes. D) ATP stores energy in carbonyl groups. When a carbonyl group is removed, energy is released to be used in cellular processes. E) ATP is an important component of cell membranes because it is nonpolar and hydrophobic.

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

Which of the following molecules is a weak acid? A) R-COOH B) R-NH2 C) R-SH D ) R-OH

A) R-COOH

Which of the following molecules is a weak base? A) R-NH2 B) R-SH C) R-OH D) R-COOH

A) R-NH2

The carbon atom is tetravalent; this means that __________. A) a carbon atom can complete its valence shell by forming four covalent bonds B) carbon readily forms ionic bonds C) carbon's first electron shell holds four electrons D) the bond angle between each bond is 90°, forming an arrangement like the points on a compass E) carbon has a total of four electrons

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

The carbon skeleton can vary in all of the following except __________. A) lacking hydrogen atoms B) length C) branching D) double bond position E) presence of rings

A) lacking hydrogen atoms

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

A) methyl group (-CH3)

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

A) organic carbon always has a hydrogen atom covalently attached to it

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

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

When three phosphate groups are covalently attached to adenosine, __________ is formed. A) ADP B) ATP C) AMP D) Pi E) glycerol phosphate

B) ATP

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

B) sulfhydryl group (-SH)

Which of the following are properties of hydrocarbons? A) Hydrophobic, polar, and charged B) Hydrophilic, a good source of stored energy, and consisting primarily of carbon and hydrogen C) Hydrophobic, nonpolar, and a good source of stored energy D) Hydrophilic, containing numerous carboxyl groups, and nonpolar E) Hydrophobic, containing numerous amine groups, and polar

C) Hydrophobic, nonpolar, and a good source of stored energy

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

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

Molecules that contain only carbon and hydrogen are __________. A) called hydrated carbons B) called inorganic carbons C) called hydrocarbons D) found only as linear chains

C) called hydrocarbons

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

C) carboxyl group (-COOH)

When a double bond joins two carbon atoms, __________ can form. A) structural isomers B) enantiomers C) cis-trans isomers D) saturated fats E) chemical groups

C) cis-trans isomers

Which element is always associated with organic chemistry? A) Sulfur B) Nitrogen C) Hydrogen D) Carbon E) Oxygen

D) Carbon

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

D) acid; amino

Which chemical group is most likely to be responsible for an organic molecule behaving as a base? A) Hydroxyl B) Carbonyl C) Carboxyl D) Phosphate E) Amino

E) Amino

Which of the following is found in all amino acids? A )-COOH B) -COH C) -OH D) -NH2 E) Both -COOH and -NH2

E) Both -COOH and -NH2

What are the six most important chemical elements of life? A) Carbon, nitrogen, calcium, oxygen, phosphate, and iron B) Carbon, nitrogen, oxygen, calcium, phosphate, and hydrogen C) Carbon, nitrogen, sulfur, hydrogen, iron, and magnesium D) Carbon, nitrogen, calcium, zinc, iron, and hydrogen E) Carbon, nitrogen, oxygen, hydrogen, phosphate, and sulfur

E) Carbon, nitrogen, oxygen, hydrogen, phosphate, and sulfur

Although the structures of the functional groups that are most important to life vary, they share one thing in common: They __________. A) all contain oxygen B) all have at least one double bond C) always cause the carbon to which they are attached to become an asymmetric carbon, thus converting the molecule into an enantiomer D) force straight chains of carbons into closed rings of carbon E) all are hydrophilic and increase the organic compound's water solubility

E) all are hydrophilic and increase the organic compound's water solubility