front 1 Triglycerides composed of glycerin and mostly polyunsaturated fatty acid residues are likely to be ___ at room temperature. | back 1 a. solid fats b. liquid oils c. gases d. waxes |
front 2 Shown below is the structure of the fatty acid, lauric acid: The boxed portion is considered to be both | back 2 a. hydrophilic and hydrophobic. b. polar and hydrophobic. c. polar and hydrophilic. d. nonpolar and hydrophilic. |
front 3 The structure of the fatty acid, palmitic acid, is | back 3 a. saturated b. monounsaturated c. polyunsaturated d. waxy |
front 4 Lecithin is found in egg whites and can be used as an emulsifying agent to keep mayonnaise from separating. Lecithin is classified as a ___.Select one: | back 4 a. phospholipid b. wax c. steroid d. glycolipid |
front 5 Animal fats and vegetable oils become rancid when exposed to air because | back 5 they are hydrogenated to form saturated fatty acids. b. carbon-carbon double bonds are oxidized in air, producing small organic molecules. c. they form amino acids in air. d. they are partially hydrogenated. |
front 6 Which enzyme is involved in the conversion of arachidonic acid into prostaglandins and thromboxanes in the body? | back 6 a. rybozymes b. cyclooxygenase c. transferases d. isomerases |
front 7 Sphingomyelins are found in ___. | back 7 a. waxes b. egg whites c. skin cells d. nerve cell membranes |
front 8 Cholesterol contains nonpolar rings and hydrocarbon chains, and also has an alcohol group (–OH). Which statement below is correct? | back 8 a. The molecule is totally hydrophobic. b. Most of the molecule is hydrophobic with the –OH being hydrophilic. c. The molecule is totally hydrophilic. d. Cholesterol molecules would line up with the alcohol group attracted by the rings. |
front 9 The structure below is best classified as a ___. | back 9 a. triglyceride b. wax c. steroid d. phospholipid |
front 10 Which of the following is released from the gallbladder into the small intestine to aid digestion by dispersing dietary lipids into fine emulsions? | back 10 a. Bile salts b. cholesterolc. eicosanoidsd. phospholipids |
front 11 The skeletal structure of docosahexaenoic acid, an essential fatty acid, is provided below. Docosahexaenoic acid is best classified as: | back 11 a. Omega-3-fatty acid b. Omega-6-fatty acid c. Saturated fatty acid d. Wax |
front 12 Identify the class of lipid to which the following molecule belongs. | back 12 a. sphingophospholipid b. triglyceride c. cholesterol d . glycerophospholipid |
front 13 Anabolic steroids can cause some serious health problems including | back 13 a. reduced circulation to the brain and liver. b. muscle atrophy and blocked arteries. c. high blood pressure and testicular atrophy. d. the interruption of nerve impulses and reduced intestinal function. |
front 14 Eicosanoids are hormones derived from arachidonic acid. Which is not an eicosanoid? | back 14 a. prostaglandin b. leukotriene c. progesterone d. thromboxane |
front 15 Which of the following is one of the products formed when the lipid below is saponified? | back 15 b. |
front 16 What is the function of nonsteroidal anti-inflammatory drugs (NSAID)? | back 16 a. To interrupt the production of prostaglandins from arachidonic acid. b. To interfere with the production of anabolic steroids. c. To facilitate the production of cyclooxygenase. d. To stimulate the production of leukotrienes. |
front 17 Sphingolipids are a class of phospholipids. | back 17 True |
front 18 The lipid that is a cell surface receptor for hormones and drugs is aSelect one: | back 18 a. glycerophopholipid. .b. ganglioside. c. sphingomyelin. d. cerebroside. |
front 19 The glycolipid molecule is characterized by having a specific residue attached to the backbone. Which is that residue? | back 19 a. phosphate b. glycerol c. lipid d. sugar |
front 20 The ___ is the location on the protein molecule where enzyme catalyzed reactions take place. | back 20 a. substrate b. zymogen c. active site d. coenzyme |
front 21 What is the net charge on the oligopeptide in the figure shown here at pH 1? | back 21 a. 3+ b. 1+ c. 2+ d. 0 |
front 22 A certain enzyme's name is glucose-6-phosphorylase. This enzyme most likely catalyzes a reaction that | back 22 a. converts glucose into six phosphorous atoms. b. synthesizes six glucose molecules. c. joins six glucose molecules to a phosphate. d. places a phosphate on the sixth carbon of glucose. |
front 23 What level of protein structure is not disturbed by denaturing? | back 23 a. tertiary structure b. primary structure c. secondary structure d. quaternary structure |
front 24 Shown here is the amino acid glycine at a pH of ___. | back 24 a. 1 (no negative 1 +) b. 7 c. 14 d. both 1 and 14 |
front 25 If an amino acid is in a neutral solution, the form the carboxyl group takes is ___. | back 25 a. —CO2– b. —CO2H+ c. —CO2 – d. —CO2H |
front 26 Which of the following substances recognized by immune system evoke production of one or more antibodies? | back 26 a. secondary proteins b. antigens c. globular proteins d. glycolipids |
front 27 Aspartic acid is classified as a polar-acidic amino acid due to | back 27 a. the —CH group to which the amide group is attached. b. the —CH2 group in the middle of the side chain. c. the amide group located on a side chain. d. the carboxyl group located on the side chain. |
front 28 Which is a means of denaturing a protein? | back 28 a. changes in temperature b. changes in pH c. use of detergents or soaps d. all of these choices |
front 29 The peptide bond that connects amino acids in proteins is actually an ___ linkage. | back 29 a. amineb b. amide c. ether d. ester |
front 30 What form does isoleucine take at pH 14? | back 30 a. |
front 31 Which of the following sentences is true? | back 31 a. Rearranging the amino acid residues in a peptide or protein changes its function. b. In an α-helix form, portions of polypeptide chain line up side by side with hydrogen bonds holding neighboring strands of sheet together. c. The order of amino acid residues in a protein is referred to as its tertiary structure. d. The overall three-dimensional shape of a protein is referred to as its primary structure. |
front 32 An inhibitor is a substance that affects an enzyme by | back 32 a. reducing the ability to act as a catalyst. b. removing the prosthetic group from an enzyme. c. reacting with the enzyme so there is less effect of the chemical reaction’s surroundings on the rate of reaction. d. stopping the separation of the enzyme from the product keeping the reaction from going to completion. |
front 33 he structure of the dipeptide, Phe-Gly, in a solution of pH 14 is ___. | back 33 a |
front 34 Protein molecules with the appropriate structure to be biologically active are native molecules.Select one: | back 34 true |
front 35 Stereoisomers exist for most of the amino acids found in nature. Which statement below is correct?Select one: | back 35 Both the D-amino acids and the L- amino acids are used by living things. b. Only the L-amino acids are incorporated in proteins. c. A common conversion is from the D-amino acid to the L-amino acid. d. L-amino acids are toxic. |
front 36 Which of the following is an example of a protein that exhibits a quaternary structure? | back 36 a. insulin b. hemoglobin c. collagen d. keratin |
front 37 he α-helix and β-pleated sheet are both forms of the ___ structure of proteins. | back 37 a. primary b. secondary c. tertiary d. quaternary |
front 38 ___ are inactive enzyme precursors that are synthesized, stored and may be activated where needed. | back 38 a. Substrates b. Zymogens c. Active sites d. Coenzymes |
front 39 Some proteins require more than one polypeptide chain to be biologically active. The level of protein structure involved is the ___ of a protein. | back 39 a. primary b. secondary c. tertiary d. quaternary |
front 40 Which of the following compounds share the steroid ring structure? | back 40 a. cholesterol and phospholipids b. phospholipids and arachidonic acid c. arachidonic acid and bile salts d. bile salts and cholesterol |
front 41 Sphingolipids are amphipathic hydrolysable lipids based on glycerol. | back 41 False |
front 42 Testosterone is produced from arachidonic acid. | back 42 False |
front 43 Which of the following lipids is not derived from cholesterol? | back 43 a. progesterone b. thromboxane c. cortisold . testosterone |
front 44 Oleic acid has the formula CH3(CH2)7(CH = CH(CH2)7CO2H. The carbon –carbon double bond in oleic acid is usually cis. Compared to saturated fatty acids with the same number of carbon atoms, cis-oleic acid will have | back 44 a lower melting point due to a kink in the hydrocarbon tail. b. stronger London forces and a higher melting point. c. bonds that fit in the packing of the hydrophobic tails, creating stronger interaction between molecules. d. no reaction with hydrogen in the presence of platinum catalyst. |
front 45 Waxes are compounds that are | back 45 a. the result of the reaction of a fatty acid and sodium hydroxide. b. extremely hydrophilic due to the head end of the compound. c. mixtures of water insoluble compounds, especially esters. d. small compounds produced when short chain fatty acids react with an alcohol. |
front 46 Trans fats are produced during the hydrogenation of fats and oils. | back 46 true |
front 47 The fatty acid, palmitoleic acid, is | back 47 a. saturated b. monounsaturated c. polyunsaturated d. waxy |
front 48 Omega-3 and Omega-6-fatty acids are essential fatty acids. Which of the following statement best describes these essential fatty acids? | back 48 a. They are very soluble in water. b. They are saturated fatty acids that the body absorbs faster. c. They are not produced in the body and must be obtained through diet. d. They are waxes found in the body. |
front 49 Fibrous proteins, because of their long fibers, tend to be soluble in water. | back 49 false |
front 50 Hydrogen bonding plays a role in the primary structure of protein. | back 50 false |
front 51 At physiological pH, most amino acids carry both a 1+ and 1- charge. This form is known as a ___. | back 51 a. zwitterion b. anion c. cation d. isoelectric ion |
front 52 he enzyme hexokinase catalyzes the transfer of a phosphate group from
ATP to carbon #6 of D-glucose and other D-hexoses. L-hexoses are not
substrates to the enzyme. | back 52 a. relative specificity b. stereospecificity c. absolute specificity d. both relative specificity and stereospecificity |
front 53 The sequence of the amino acids in a protein is known as the ___ structure. | back 53 a. primary b. secondaryc. tertiaryd. quaternary |
front 54 The net charge of peptides and proteins affects their solubility. | back 54 true |
front 55 The overall three-dimensional shape of a protein is determined by its ___ and is known as the ___ structure of a protein. | back 55 a. amino acid residues/primary b. amino acid residues/tertiary c. isoelectric point/secondary d. hydrogen bonding/secondary |
front 56 In which solvent would lipids be most soluble? | back 56 a. hexane b. water c. methyl alcohol d. ethyl alcohol |
front 57 Which compounds are responsible for causing pain and inflammation? | back 57 a. anabolic steroids b. adrenocorticoids c. prostaglandins d. leukotrienes |
front 58 The effect of the hydrogenation of oils is to | back 58 . remove double bonds. b. cause the oils to remain as liquids. c. make the oils boil at a lower temperature.d. make the oils oxidize. |
front 59 All commonly occurring fatty acids contain trans alkene groups. | back 59 false |
front 60 The difference between the sphingolipids and the glycerophospholipids is that the sphingolipids | back 60 a. have three alcohol residues that replace the fatty acid residues.b. have one phosphate, but it is attached to the fatty acid residue, not the glycerol.c. have three phosphates, not one, and they are attached to all of the fatty acids. d. include sphingosine with a phosphate attached to it, and an alcohol residue. |
front 61 A contributing factor to the tertiary structure of a protein is a covalent bond between two atoms of ___. | back 61 a. sulfur b. hydrogen c. carbon d. nitrogen |
front 62 Where is the peptide bond located in this dipeptide? | back 62 a. the CO—NH joining serine and the valine b. the doubly bonded oxygen just left of center between the amino acids \c. the CH—CO on the top of the serine going to the rightd. the NH—CH between the serine and valine |
front 63 Which is an α-amino acid? | back 63 a. |
front 64 The structures of the amino acids proline and glycine are shown below. Which of the following statements is true? | back 64 a. glycine is an α-amino acid, but proline is notb b. both proline and glycine are chiral molecules c. glycine is achiral and proline is chiral d. proline exists as four enantiomers |
front 65 Because amino acids contain polar covalent bonds, they are hydrophilic and will dissolve water. | back 65 true |
front 66 The structure of palmitate ion derived from the fatty acid, palmitic
acid, is | back 66 a. hydrophobicb. lipophobicc. hydrophilic d . amphipathic d . amphipathic |
front 67 The hormone that is the starting point for the production of the adrenocorticoid hormones and testosterone is | back 67 a. progesterone. b. estrogen. c. cholesterol. d. chylomicrons. |
front 68 What kind of noncovalent interaction occurs between the –NH3
+
| back 68 a. salt bridge b. hydrogen bonding c. covalent disulfide bond d. hydrophobic effect |
front 69 Many of the chemical reactions of living things involve enzymes, which are | back 69 a. proteins that are in the form of parallel sheets. b. proteins that catalyze reactions. c. small DNA molecules. d. denatured proteins. |