Biology Homework Chapter 2

The capacity to do work is known as ______. a. energy b. kinetic energy c. potential energy d. momentum

a. energy

Which ions are produced when water ionizes? a. H- b. OH- c. O2 d. OH+ e. H+

b. OH- E. H+

Which of the following molecules are predicted to easily dissolve in water? a. Carbohydrates that contain -OH groups b. Ions that carry full electric charges c. Oils that contain C-H groups

a. Carbohydrates that contain -OH groups b. Ions that carry full electric charges

Molecules are likely to dissolve easily in water if they contain what type of bonds? a. Ionic bonds b. Nonpolar covalent bonds c. Polar covalent bonds

a. Ionic bonds c. Polar covalent bonds

______ are combinations of two or more ______, which are the fundamental units of matter. a. Molecules; atoms b. Molecules; electrons c. Atoms; molecules d. Atoms; protons

a. Molecules; atoms

In a micelle, which portion of the amphipathic molecules are oriented toward the surface of the sphere? a. The polar region b. The nonpolar region c. The hydrophobic region

a. The polar region

Which of the following statements describe hydrophilic molecules? a. They are soluble in water. b. They contain many nonpolar covalent bonds. c. They are uncharged. d. They are smaller than hydrophobic molecules.

a. They are soluble in water.

What type of compound minimizes pH fluctuations in the fluids of living organisms? a. buffer b. base c. water d. acid

a. buffer

To freeze water, energy is ______. a. released b. added c. not a consideration

a. released

Substances dissolved in liquid are called ______. a. solutes b. solutions c. solvents d. micelles

a. solutes

Which of the following describe molecules that only have hydrophobic regions? a. Have atoms with partial positive and partial negative charges b. Are relatively insoluble in water c. Form micelles when placed in water d. Contain many nonpolar covalent bonds e. Dissolve well in nonpolar solvents

b. Are relatively insoluble in water d. Contain many nonpolar covalent bonds e. Dissolve well in nonpolar solvents

Compared with liquid water, ice has ______. a. fewer hydrogen bonds between individual water molecules b. more hydrogen bonds between individual water molecules c. a less orderly arrangement of water molecules d. a more orderly arrangement of water molecules

b. more hydrogen bonds between individual water molecules d. a more orderly arrangement of water molecules

What part of an amphipathic molecule would be oriented toward the center of a micelle? a. The charged region b. The nonpolar region c. The polar region

b. nonpolar region

Here are three descriptions of the modern model of atomic structure. Which is the best? a. A collection of positive and negative charges uniformly distributed throughout the atom b. A central nucleus surrounded by electrons traveling in clearly defined orbits c. A central nucleus surrounded by cloudlike orbitals containing electrons

c. A central nucleus surrounded by cloudlike orbitals containing electrons

Which of the following best describes how a hydrogen bond forms? a. Hydrogen and oxygen share electrons when each is present on polar molecules. b. Hydrogen forms a covalent bond with another atom and shares its electrons unequally. c. A partially positive hydrogen atom and a partially negative atom in another molecule are attracted by electrostatic interactions.

c. A partially positive hydrogen atom and a partially negative atom in another molecule are attracted by electrostatic interactions.

Which of the following elements are important constituents of skeletons? a. Potassium and sodium b. Phosphorus and potassium c. Calcium and phosphorus d. Iron and copper

c. Calcium and phosphorus

Which types of chemical bonds are easily broken in water? a. Polar covalent bonds b. Nonpolar covalent bonds c. Ionic bonds d. Hydrogen bonds

c. Ionic bonds d. Hydrogen bonds

Hydrolysis reactions ______. a. create molecules via the loss of a smaller molecule b. create molecules via the loss of water c. break apart molecules via water

c. break apart molecules via water

Living organisms minimize changes in their internal pH using compounds called ______. a. acids b. bases c. buffers d. enzymes e. catalysts

c. buffers

The ______ of a solution is the negative base 10 logarithm of the H+ concentration of the solution. a. heat of vaporization b. heat capacity c. pH d. equilibrium constant

c. pH

The concentration of a liquid is defined as the amount of ______ dissolved in a unit volume of solution. a. solvent b. moles c. solute

c. solute

Which of the following solutions contains the highest concentration of protons? a. A solution with pH 10.0 b. A solution with pH 7.0 c. A solution with pH 5.0 d. A solution with pH 2.0

d. A solution with pH 2.0

Which of the following is an element? a. Water b. Gasoline c. Coffee d. Carbon

d. Carbon

Colligative properties depend on the ______ dissolved in a solution. a. size of particles b. type of particles c. electrical charge on particles d. number of particles

d. number of particles

Phosphorus exists in several isotopes, including 31P and 32P. These are expected to have different ______. a. numbers of electrons b. numbers of protons c. atomic numbers d. numbers of neutrons

d. numbers of neutrons