Unit 2 bio 2

HCl is considered a strong acid. This means that it donates H+ ions in solution. As such, what ionization constant would you use when calculating solute potential? a. 1 b. 2 c. 3 d. 4

2

What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons? a. 15amu(atomic mass units) b. 16amu(atomic mass units) c. 30amu(atomic mass units) d. 31amu(atomic mass units) e. 46amu(atomic mass units)

31amu (atomis mass units)

How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution? a. 1 b. 14 c. 92 d. 1 X 10^7 e. 6.02 X 10^23

6.02 X 10^23

One mole (mol) of a substance is a. 6.02 X 10^23 molecules of the substance. b. 1 g of the substance dissolved in 1 L of solution. c. the largest amount of the substance that can be dissolved in 1 L of solution. d. equal in mass for all molecules.

6.02 X 10^23 molecules of the substance

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called? a. a covalent bond b. a hydrogen bond c. an ionic bond d. a hydrophilic bond e. a hydrophobic bond

A hydrogen bond

Which of the following is (are) true about the carbon atoms present in all organic molecules? a. They were incorporated into organic molecules by plants. b. They were processed into sugars through photosynthesis. c. They are ultimately derived from carbon dioxide. d. A, B, and C are correct.

A, B, and C are correct

Which of the following is (are) true for the class of large biological molecules known as lipids? a. They are insoluble in water. b. They are an important constituent of cell membranes. c. They contain twice as much energy as an equivalent weight of polysaccharide. d. A, B, and C are correct.

A, B, and C are correct

The R group or side chain of the amino acid serine is -CH2-OH. The R group or side chain of the amino acid alanine is -CH3. Where would you expect to find these amino acids in a globular protein in aqueous solution? a. Serine would be in the interior, and alanine would be on the exterior of the globular protein. b. Both serine and alanine would be on the exterior of the globular protein. c. Alanine would be in the interior, and serine would be on the exterior of the globular protein. d. Both serine and alanine would be in the interior of the globular protein.

Alanine would be in the interior, and serine would be on the exterior of the globular protein

What do cohesion, surface tension, and adhesion have in common with reference to water? a. All increase when temperature increases. b. All are produced by ionic bonding. c. All are properties related to hydrogen bonding. d. All have to do with nonpolar covalent bonds.

All are properties related to hydrogen bonding

If the pH of a solution is decreased from 9 to 8, it means that the a. concentration of H+ has decreased 10 times what it was at pH 9. b. concentration of H+ has increased 10 times what it was at pH 9. c. concentration of OH- has increased 10 times what it was at pH 9. d. concentration of OH- has decreased 10 times what it was at pH 9. e. B and D are correct.

B and D are correct

What is the name of the functional group shown in the following figure? a. carbonyl b. ketone c. aldehyde d. carboxyl e. hydroxyl

Carboxyl

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? a. Dehydration reactions assemble polymers, and hydrolysis breaks down polymers. b. Hydrolysis only occurs in the urinary system, and dehydration reactions only occur in the digestive tract. c. Dehydration reactions can occur only after hydrolysis. d. Hydrolysis creates monomers, and dehydration reactions break down polymers.

Dehydration reactions assemble polymers, and hydrolysis breaks down polymers

Which drawing depicts the electron configuration of neon 20Ne10 a. Drawing A b. Drawing B c. Drawing C d. Drawing D e. Drawing E

Drawing E

Which is a hydroxyl functional group? a. Group A b. Group B c. Group C d. Group D e. Group E

Group A

Which is a carbonyl functional group? a. Group A b. Group B c. Group C d. Group D e. Group E

Group B

Use the figure below to answer the following questions. Which is an amino functional group? a. Group A b. Group B c. Group C d. Group D e. Group E

Group D

Which is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules? a. Group A b. Group B c. Group C d. Group D e. Group E

Group E

Which of the following molecules contains the strongest polar covalent bond? a. H2 b. O2 c. CO2 d. H2O e. CH4

H2O

Humans can digest starch but not cellulose because a. the monomer of starch is glucose, while the monomer of cellulose is galactose. b. the monomer of starch is glucose, while the monomer of cellulose is maltose. c. humans have enzymes that can hydrolyze the alpha glycosidic linkages of starch but not the beta glycosidic linkages of cellulose. d. humans harbor starch-digesting bacteria in the digestive tract.

Humans have enzymes that can hydrolyze the alpha glycosidic linkages of starch but not the beta glycosidic linkages of cellulose

When two atoms are equally electronegative, they will interact to form a. equal numbers of isotopes. b. ions. c. polar covalent bonds. d. nonpolar covalent bonds. e. ionic bonds.

Non polar covalent bonds

The dehydration reaction illustrated in the figure below results in the formation of a (an) a. phosphodiester linkage (linking nucleotides). b. glycosidic linkage (joining sugars). c. peptide bond (joining amino acids). d. ester linkage (linking fatty acid tails).

Peptide bond (joining amino acids)

An example of a hydrogen bond is the bond between a. C and H in methane (CH4). b. the H of one water molecule and the O of another water molecule. c. Na+and Cl- in salt. d. the two hydrogen atoms in a molecule of hydrogen gas (H2). e. Mg+and Cl- in MgCl2.

The H of one water molecule and the O of another water molecule

Water is able to form hydrogen bonds because a. oxygen has a valence of 2. b. the bonds that hold together the atoms in a water molecule are polar covalent bonds. c. the oxygen atom in a water molecule has a weak positive charge. d. each of the hydrogen atoms in a water molecule is weakly negative in charge.

The bonds that hold together the atoms in a water molecule are polar covalent bonds

A given solution contains 0.0001(10-4) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution? a. acidic: H+ acceptor (decreases H+ concentration of solution) b. basic: H+ acceptor c. acidic: H+ donor (increases H+ concentration of solution) d. basic: H+ donor e. neutral

acidic: will give H+ to weak acids, but accept H+ from strong acids

Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus? a. atomic mass b. atomic weight c. atomic number d. mass weight e. mass number

atomic number

A molecule with the chemical formula C16H32O16 is probably a a. hydrocarbon. b. protein. c. carbohydrate. d. lipid.

carbohydrate

Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom? a. Carbon has 6 to 8 neutrons. b. Carbon has a valence of 4. c. Carbon always forms ionic bonds. d. Carbon always forms bonds that are hydrophilic.

carbon has a valence of 4

About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? a. carbon, sodium, chlorine, nitrogen b. carbon, sulfur, phosphorus, hydrogen c. oxygen, hydrogen, calcium, sodium d. carbon, hydrogen, nitrogen, oxygen e. carbon, oxygen, sulfur, calcium

carbon, hydrogen, nitrogen, oxygen

The ionic bond of sodium chloride is formed when a. chlorine gains an electron from sodium. b. sodium and chlorine share an electron pair. c. sodium and chlorine both lose electrons from their outer valence shells. d. chlorine gains a proton from sodium.

chlorine gains an electron from sodium

What type(s) of bond(s) does carbon have a tendency to form? a. ionic b. hydrogen c. covalent d. A and B only

covalent

What do atoms form when they share electron pairs? a. elements b. ions c. aggregates d. isotopes e. covalently bonded molecules

covalently bonded molecules

Which type of interaction stabilizes the alpha helix and the beta pleated sheet structures of proteins? a. nonpolar covalent bonds b. hydrophobic interactions c. hydrogen bonds d. peptide bonds

hydrogen bonds

Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates? a. nitrogen b. calcium c. iodine d. sodium e. phosphorus

iodine

What kind of a bond does NH4+ form with Cl- to make ammonium chloride salt (NH4Cl)? Hint: The + and - indicate a transfer of electrons (either loss to form a + or gain to form a -). a. nonpolar covalent b. polar covalent c. ionic d. hydrogen

ionic

A molecule with the formula C18H36O2 is probably a a. protein. b. lipid. c. carbohydrate. d. nucleic acid.

lipid

Triacylglycerol is a a. carbohydrate with three sugars joined together by glycosidic linkages. b. molecule formed from three alcohols by dehydration reactions. c. protein with tertiary structure. d. lipid made with three fatty acids and glycerol.

lipid made with three fatty acids and glycerol

Hydrophobic substances such as vegetable oil are a. nonpolar substances that repel water molecules. b. nonpolar substances that have an attraction for water molecules. c. polar substances that repel water molecules. d. polar substances that have an affinity for water. e. charged molecules that hydrogen-bond with water molecules.

nonpolar substances that repel water molecules

How do isotopes of the same element differ from each other? a. number of protons b. number of electrons c. number of neutrons d. valence electron distribution

number of neutrons

A covalent chemical bond is one in which a. electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged. b. protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms. c. outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms. d. outer-shell electrons of one atom are transferred to the inner electron shells of another atom. e. the inner-shell electrons of one atom are transferred to the outer shell of another atom.

outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms

What would be the pH of a solution with a hydroxide ion [OH-] concentration of 10-12M? a. pH 2 b. pH 4 c. pH 10 d. pH 12 e. pH 14

pH 2

In a single molecule of water, the two hydrogen atoms are bonded to a single oxygen atom by a. hydrogen bonds. b. nonpolar covalent bonds. c. polar covalent bonds. d. ionic bonds. e. van der Waals interactions.

polar covalent bonds

The picture below illustrates a solute molecule surrounded by a hydration shell of water. Use it to answer the following question. Based on your knowledge of the polarity of water molecules, the solute molecule is most likely a. positively charged. b. negatively charged. c. without charge. d. hydrophobic. e. nonpolar.

positively charged

The mass number of an element can be easily approximated by adding together the number of ____ in an atom of that element. a. protons and neutrons b. energy levels c. protons and electrons d. neutrons and electrons

protons and neutrons

Which of the following solutions has the greatest concentration of hydroxide ions [OH-]? a. lemon juice at pH 2 b. vinegar at pH 3 c. tomato juice at pH 4 d. urine at pH 6 e. seawater at pH 8

seawater at pH 8

The 20 different amino acids found in polypeptides exhibit different chemical and physical properties because of different a. amino groups b. side chains (R groups) c. carboxyl groups d. central carbons

side chains (R groups)

The two molecules shown in the following figure are best described as a. optical isomers. b. radioactive isotopes. c. structural isomers. d. nonradioactive isotopes. e. geometric isomers.

structural isomers

What is the reason why hydrocarbons are not soluble in water? a. The majority of their bonds are polar covalent carbon to hydrogen linkages. b. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. c. They are hydrophilic. d. They exhibit considerable molecular complexity and diversity. e. They are lighter than water.

the majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages

Which of the following statements is true about buffer solutions? a. They maintain a constant pH when bases are added to them but not when acids are added to them. b. They maintain a constant pH when acids are added to them but not when bases are added to them. c. They maintain a constant pH of exactly 7 in all living cells and biological fluids. d. They maintain a relatively constant pH.

they maintain a relatively constant pH when either acids or bases are added to them

3H is a radioactive isotope of hydrogen. One difference between hydrogen-1 and hydrogen-3 is that hydrogen-3 has a. one more neutron and one more proton than hydrogen-1. b. one more proton and one more electron than hydrogen-1. c. one more electron and one more neutron than hydrogen-1. d. two more neutrons than hydrogen-1. e. two more protons than hydrogen-1.

two more neutrons than hydrogen-1

The tertiary structure of a protein is the a. unique three-dimensional shape of the fully folded polypeptide. b. order in which amino acids are joined in a polypeptide chain. c. organization of a polypeptide chain into an á helix or â pleated sheet. d. overall protein structure resulting from the aggregation of two or more polypeptide subunits.

unique three-dimensional shape of the fully folded polypeptide

The molecule shown in the figure below is a a. polypeptide. b. polysaccharide. c. unsaturated fatty acid. d. saturated fatty acid.

unsaturated fatty acid

What is the molecule illustrated in the figure below? a. a polysaccharide b. an unsaturated fatty acid c. a saturated fatty acid d. a steroid similar to cholesterol

unsaturated fatty acid

An amino acid includes a carbon skeleton which is covalently bonded to both an amino group and a carboxyl group. When placed in water it a. would function only as an acid because of the carboxyl group. b. would function only as a base because of the amino group. c. would function as neither an acid nor a base. d. would function as both an acid because of the carboxyl group and a base because of the amino group. e. is impossible to determine how it would function.

would function as both and acid because of the carboxyl group and a base because of the amino grop