英语论文网

other destroy them. C. the atoms of the reactants are exactly as the atoms of the products. D. the reactants contain the same number of atoms as the products. E. although the atoms of a reaction’s reactants products identical to each other, their molecular formulae differ.
17. Lactose intolerance is the inability to: A. produce milk proteins. B produce lactose. C. Digest cellulose. D. Digest lactose. E. digest milk fats.
18. Carbon is able to form an immense diversity of organic compounds because of carbon’s : A.tendency to form covalent bonds. B. ability to bond with up to 4 other atoms. C capacity to form single and double bonds. D. ability to bond together to form extensive, branched, or un-branched “carbon skeletons”
19. organic compounds: A. always contain nitrogen. B.Are synthesized only by animal cells. C. always contain carbon. D. Can only be synthesized in a laboratory. E. Always contain oxygen.
20. “oil and water don’t mix” is true because: A. oil exhibits Polarity and water does not. B.water exhibits polarity and oil does not. C. Oil is hydrophilic. D. water is hydrophobic. E. oil is an organic compound and water is not.
21. A hydroxyl group is : A. also called a carbonyl group. B. characteristic of proteins. C.Hydrophobic. D. characteristic of alcohols. E. None of the choices are correct.
22. Which of the following is an amino group? A. –OH B. –NH2 C. –COOH. D. –CO. E.-CH3
23.Many names for sugar end in the suffix: A.-acid .B. –OSE. C.-HYDE. D.-ASE. E.-ING
24. Foods that are high in fiber are mostly derived from; A. plants. B. Dairy products. C.Meat. D. Fish. E. Any of these choices.
25. Fatty acids with double bonds between some of their carbons are said to be. A. unsaturated. B. saturated. C. completely hydrogenated. D. triglycerides. E. monoglycerides.
26. which of the following statements is false? Enzymes : A.increase the rate of chemical reactions. B. function as chemical catalysts. C. Regulate virtually all chemical reactions in a cell. D.Are produced by cells. E. Are monomer units used to build proteins.
27. Glucose molecules are to starch as _____are to proteins. A. oils. B. amino acids. C.fatty acids. D. waxes. E. lards.
28.Amino acids can be distinguished from one another by: A. the number of R groups on the amino acid molecules. B. the chemical properties of their R groups. C. the tyl[pe of bonds between the R group and the rest of the molecule. D. The chemical properties of their amino and carboxyl groups. E.All of the above choices are correct.
29. which level of the protein structures consists of amino acids assembled in a specific order?
A. primary. B.secondary. C.tertiary.D.quaternary.E.none of the above.
30. which one of the following substances is not a lipid?
A. wax. B. cholesterol .C. cellulose. D. steroids. E.OILS.
31. Which of the following is not a function of proteins?
A. provide structural components. B. store the genetic information of a living organism. C. movement of muscles. D.catalyze reactions in the cells. E.transport substances through the bloodstream.
32. the structural formulas of amino acids are the same except for the: A. carboxyl group.B.alpha carbon. C.Amino group. D.Side (R) group. E.Hydrogen bonding.
33. Compared to an un-catalyzed reaction, an enzyme-catalyzed reaction. A. uses less reactants. B.produces different products. C.occurs at a faster rate. D.Requires more energy. E .requires a highe