Module 2 Quiz

Which of the following correctly describes chemical equilibrium? - Forward and reverse reactions continue with no effect on the concentrations of the reactants and products. - Concentrations of products are higher than the concentrations of the reactants. - Forward and reverse reactions have stopped so that the concentration of the reactants equals the concentration of the products. - Reactions stop only when all reactants have been converted to products. - There are equal concentrations of reactants and products, and the reactions have stopped.

- Forward and reverse reactions continue with no effect on the concentrations of the reactants and products.

The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil? - The hydrogenated vegetable oil has a lower melting point. - The hydrogenated vegetable oil stays solid at room temperature. - The hydrogenated vegetable oil has more "kinks" in the fatty acid chains. - The hydrogenated vegetable oil has fewer trans fatty acids. - The hydrogenated vegetable oil is less likely to clog arteries.

- The hydrogenated vegetable oil stays solid at room temperature.

One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3- and a hydrogen ion (H+). Thus, H2CO3 ↔ HCO3- + H+ If the pH of the blood increases, one would expect: - a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-. - an increase in the concentration of H2CO3 and a decrease in the concentration of HCO3-. - a decrease in the concentration of HCO3- and an increase in the concentration of H+. - an increase in the concentration of HCO3- and a decrease in the concentration of OH-. - a decrease in the concentration of HCO3- and an increase in the concentration of both H2CO3 and H+.

- a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-.

A neutral atom must contain: - an equal number of protons and neutrons. - an equal number of protons, neutrons, and electrons. - an equal number of protons and electrons. - an equal number of neutrons and electrons.

- an equal number of protons and electrons.

If a specimen contains 30% adenine in its DNA then how much cytosine will there be? 40% 30% 20% 10% Cannot be determined.

20%

Which of the following is a nonstandard amino acid? Glycine Cysteine Acetyllysine Alanine Valine

Acetyllysine

Identify the asymmetric carbon in this molecule. A B C D E

B

The two molecules shown in this figure are best described as: Enantiomers. Radioactive Isotopes. Structural Isomers. Nonisotopic Isomers. Cis-Trans Isomers.

Cis-Trans Isomers.

A molecule with the formula C18H36O2 is probably a Carbohydrate. Fatty Acid. Protein. Nucleic Acid. Hydrocarbon.

Fatty Acid.

All of the following are considered "weak" interactions in proteins, except: Hydrogen Bonds. Hydrophobic Interactions. Ionic Bonds. Peptide Bonds. Van Der Waals Forces.

Peptide Bonds.

If 14C-labeled uridine triphosphate is added to the growth medium of cells, what macromolecules will be labeled? Phospholipids DNA RNA both DNA and RNA Protein

RNA

Which of the following is not a constituent of deoxyribonucleotides? Phosphate Moieties Deoxyribose Sugar Ribose Sugar Organic Bases Adinine

Ribose Sugar

If the pH of a solution is decreased from 9 to 8, it means that the: - concentration of H+ has decreased to one-tenth (1/10) what it was at pH 9. - concentration of H+ has increased tenfold (10X) compared to what it was at pH 9. - concentration of OH- has increased tenfold (10X) compared to what it was at pH 9. - concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9. - concentration of H+ has increased tenfold (10X) and the concentration of OH- has decreased to one-tenth (1/10) what they were at pH 9.

concentration of H+ has increased tenfold (10X) and the concentration of OH- has decreased to one-tenth (1/10) what they were at pH 9.

Which of these molecules is not formed by dehydration reactions? fatty acids disaccharides DNA protein amylose

fatty acids

Humans can digest starch but not cellulose because - the monomer of starch is glucose, while the monomer of cellulose is galactose. - humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose. - humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose. - humans harbor starch-digesting bacteria in the digestive tract. - the monomer of starch is glucose, while the monomer of cellulose is glucose with a nitrogen-containing group.

humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose.

What functional groups are present on this molecule? ether and aldehyde hydroxyl and aldehyde hydroxyl and carboxylic acid hydroxyl and ester hydroxyl and ketone

hydroxyl and aldehyde

What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12 M? pH 2 pH 4 pH 10 pH 12 pH 14

pH 2

Which functional group is not present in this molecule? carboxyl sulfhydryl hydroxyl amino

sulfhydryl

A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it: - would function only as an acid because of the carboxyl group. - would function only as a base because of the amino group. - would function as neither an acid nor a base. - would function as both an acid and a base. - is impossible to determine how it would function.

would function as both an acid and a base.