AP Biology - Unit 1: Chemistry of Life Review

Water is an excellent solvent. Select the property that justifies this statement.

• As a polar molecule, it can surround and dissolve ionic and polar molecules.

• It forms ionic bonds with ions, hydrogen bonds with polar molecules, and hydrophobic interactions with nonpolar molecules.

• It forms hydrogen bonds with itself so cohesion is possible.

• It is liquid and will adhere to many substances

How many electron pairs does carbon share in order to complete its valence shell?

• 2

• 4

• 6

• 8

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A carbon atom is most likely to form what kind of bond(s) with other atoms?

• ionic

• hydrogen

• covalent

• covalent and hydrogen

• ionic, covalent, and hydrogen

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Why are hydrocarbons insoluble in water?

• The majority of their bonds are polar covalent carbon–to–hydrogen linkages.

• The majority of their bonds are nonpolar covalent carbon–to–hydrogen linkages.

• They are hydrophilic.

• They exhibit considerable molecular complexity and diversity.

• They are lighter than water.

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

• Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.

• Dehydration reactions eliminate water from lipid membranes, and hydrolysis makes lipid membranes water permeable

• Dehydration reactions can occur only after hydrolysis.

• Dehydration reactions ionize water molecules and add hydroxyl groups to polymers; hydrolysis reactions release hydroxyl groups from polymers

Which of the following statements concerning saturated fats is not true?

• They are more common in animals than in plants.

• They have multiple double bonds in the carbon chains of their fatty acids.

• They generally solidify at room temperature.

• They contain more hydrogen than unsaturated fats having the same number of carbon atoms

• They are one of several factors that contribute to atherosclerosis.

There are 20 different amino acids. What makes one amino acid different from another?

• different side chains (R groups) attached to a carboxyl carbon

• different side chains (R groups) attached to the amino groups

• different side chains (R groups) attached to an α carbon

• different structural and optical isomers

The structural level of a protein least affected by a disruption in hydrogen bonding is the

• primary level

• secondary level

• tertiary level

• quaternary level

Which of the following takes place as an ice cube cools a drink?

• Evaporation of the water in the drink increases.

• The specific heat of the water in the drink decreases.

• A calorie of heat energy is transferred from the ice to the water of the drink

• Kinetic energy in the drink decreases

• Molecular collisions in the drink increase

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You have two beakers. One contains pure water; the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen.

• Equal amounts of NaCl crystals will dissolve in both water and methanol

• NaCl crystals will dissolve readily in water but will not dissolve in methanol

• NaCl crystals will not dissolve in either water or methanol

• NaCl crystals will dissolve readily in methanol but will not dissolve in water

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