BioChemistry

Question 1.1. Rank butane (CH3CH2CH2CH3), butanoic acid (CH3CH2CH2COOH), and pentane (CH3CH2CH2CH2CH3) in order of increasing boiling point. (From lowest to highest.) (Points : 3)

butane < butanoic acid < pentane butane < pentane < butanoic acid butanoic acid < pentane < butane pentane < butanoic acid < butane

Question 2.2. Choose the equilibrium constant that indicates the greatest relative amount of reactant concentration at equilibrium. (Points : 3)

1.1 x 10–7 2.3 x 107 6.7 x 102 8.3 x 10–2

Question 3.3. Which of the following is the conjugate acid of NH3? (Points : 3)

NH2- NH4+ HNO3 H3O+

Question 4.4. What volume of 0.200 M HCl is required to completely neutralize 50.00 mL of 0.150 M KOH? (Points : 3)

7.50 mL 50.0 mL 66.7 mL 37.5 mL

Question 5.5. The fluid mosaic model proposes that (Points : 3)

membranes can move like a fluid. proteins are embedded into the cell membrane. materials that are fluid move across a membrane. the composition of membranes includes a mosaic fluid

Question 6.6. The IUPAC name of the molecule below is (Points : 3)

hydroxyl -2,4-dichlorocyclohexene 3,4-dichlorophenol 2,4-dichlorophenol 1,3-dichlorophenol

Question 7.7. Which of the following is the conjugate base of the acid, carbonic acid? (Points : 3)

H2CO3 H2O H3O+ HCO3–

Question 8.8. How many alkane constitutional isomers exist with the formula C5H12? (Points : 3)

2 3 4 more than 5

Question 9.9. The side chain of the amino acid tyrosine is shown here. The side chain is classified as ___. (Points : 3)

nonpolar polar-acidic polar-basic polar-neutral

Question 10.10. Which of the following lipids is not derived from cholesterol? (Points : 3)

progesterone thromboxane cortisol testosterone 51.Which is an α-amino acid? *a) b) c) d)

Question 11.11. Antacids may contain which ion to reduce acidity? (Points : 3)

Na+ CO32– Al3+ Cl–

Question 12.12. In which of the following levels of protein structure can hydrogen bonding NOT play a role? (Points : 3)

primary secondary tertiary quaternary

Question 13.13. What is the pH of a solution in which [H3O]+ is 2.2 x 10-12 M? (Points : 3)

2.34 4.54 x 10-3 11.66 8.42

Question 14.14. What level of protein structure is not disturbed by denaturing? (Points : 3)

tertiary structure primary structure secondary structure quaternary structure

Question 15.15. The pH of a 1.25 x 10-3 M NaOH solution is: (Points : 3)

2.90 7.00 11.1 3.10 10.9

Question 16.16. What is the concentration of [H3O+] in an aqueous solution when the [OH-] is 5.2 x 10-9 M? (Points : 3)

1.9 x 10-6 M 5.7 M 1.0 x 10-14 M 9.8 x 10-9 M

Question 17.17. The element found in the center of the heme prosthetic group is ___. (Points : 3)

iron sulfur nitrogen carbon

Question 18.18. The Ka for the reaction of acetic acid and water shown below is 1.8 x 10-5. Which of the following statements is true at pH 7? (Points : 3)

there is much more acetic acid than acetate ion there is more acetate ion than acetic acid the concentration of acetate ion is equal to that of acetic acid the pH is lower than pKa of acetic acid

Question 19.19. Which of the following statements is true about alkanes? (Points : 3)

alkanes contain polar bonds alkanes are attracted to one another by London forces alkanes are polar molecules alkanes are unsaturated hydrocarbons

Question 20.20. The structure of glycerophospholipids contains (Points : 3)

a phosphate group, glycerol, three fatty acids, and a sugar molecule. a phosphate group, glycerol, two fatty acids, and an alcohol molecule. a phosphate group, a cyclic carbon ring, and variable numbers of fatty acids. a phosphate group, a carbohydrate molecule, an alcohol, and fatty acids.

Question 21.21. Kw, the equilibrium constant for the ionization of water by the equation below, is 1.0 x 10-14. What does that mean when we are considering pure water? (Points : 3)

More ions exist than water molecules. The majority of the molecules present are in the form of H2O. The amount of water is the same as the amount of the ions present. There will always be more hydronium ions present than water at equilibrium.

Question 22.22. Carbon must form how many bonds? (Points : 3)

1 2 3 4

Question 23.23. What is the function of nonsteroidal anti-inflammatory drugs (NSAID)? (Points : 3)

To interrupt the production of prostaglandins from arachidonic acid. To interfere with the production of anabolic steroids. To facilitate the production of cyclooxygenase. To stimulate the production of leukotrienes.

Question 24.24. You produce 500 mL of a 0.001 M HClO4, which ionizes completely in water. What is the pH you should expect? (Points : 3)

pH = 0.5 pH = 3.0 pH = 2.7 pH = 500

Question 25.25. The α-helix and β-pleated sheet are both forms of the ___ structure of proteins. (Points : 3)

primary secondary tertiary quaternary

Question 26.26. The ethylammonium ion, CH3CH2NH3+ has a pKa of 10.81. It reacts with water to form ethylamine, CH3CH2NH2 and H3O+ as shown below. Which of the following statements is true at pH 7? (Points : 3)

ethylammonium ion predominates ethylamine predominates the concentration of ethylamine equals that of ethylammonium ion the pH is higher than pKa of the ethylammonium ion

Question 27.27. Which of the following is the conjugate acid of the bicarbonate ion, HCO3-? (Points : 3)

H2CO3 CO32- CO2 H3O+

Question 28.28. A solution in which the concentration of H+ is greater than the concentration of OH- will (Points : 3)

have a pH greater than 7.0 and be basic. have a pH less than 7.0 and be basic. have a pH greater than 7.0 and be acidic. have a pH less than 7.0 and be acidic.

Question 29.29. Whenever an equilibrium constant, Keq, has a value greater than 1, which of the following statements is true at equilibrium? (Points : 3)

The concentration of reactants is greater than the concentration of the products. The concentration of products is the same as the concentration of reactants. The concentration of the products is greater than the concentration of the reactants. Relative composition of reaction mixture cannot be predicted.

Question 30.30. The term commonly used for a chain of amino acids 100 units long is ___. (Points : 3)

peptide oligopeptide polypeptide centapeptide

Question 31.31. Which material would be effective for neutralizing a minor acid spill? (Points : 3)

soap solution vinegar solution baking soda household ammonia

Question 32.32. One characteristic of basic solution is that (Points : 3)

the solution would turn litmus red. the solution would have a slippery feel to it. the solution would have a sour taste. the solution would dissolve some metals.

Question 33.33. Give the correct IUPAC name for the following molecule: (Points : 3)

3, 4-Dimethylpentane 2,3-Dimethyl heptane 2,3-Dimethylpentane 1,1,2-Trimethylpentane

Question 34.34. A Ka can be calculated for some chemical reactions. The Ka is (Points : 3)

the Keq for the reaction to the right. the Keq for the reaction to the left. the Keq for the dissociation of an acid. the pH of a very weak solution.

Question 35.35. The equation: has the following equilibrium constant expression. (Points : 3)