Molbio Finals PDF

LIPIDS b. involves the second carbon from the carboxyl Quiz 1 end of the carbon chain 1. A lipid is any substance of biochemical origin that c. involves the second carbon from the methyl end...

LIPIDS b. involves the second carbon from the carboxyl Quiz 1 end of the carbon chain 1. A lipid is any substance of biochemical origin that c. involves the second carbon from the methyl end is of the carbon chain a. soluble in water but insoluble in nonpolar d. no correct response solvents b. insoluble in water but soluble in nonpolar solvents Quiz 3 c. soluble in both water and nonpolar solvents 1. In which of the following pairs of fatty acids does d. no correct response the first listed acid have a greater water solubility 2. Which of the following is not a biochemical than the second listed acid? function classification for lipids? a. 18:0 acid and 14:0 acid a. membrane lipid b. 16:0 acid and 18:0 acid b. messenger lipid c. 20:0 acid and 16:0 acid c. emulsification lipid d. no correct response d. no correct response 2. In which of the following pairs of fatty acids does 3. The saponifiable/nonsaponifiable classification the first listed acid have a lower melting point than system for lipids is based on the second listed acid? a. lipid behavior in acidic solution a. 16:0 acid and 16:1 acid b. lipid behavior in basic solution b. 18:2 acid and 18:0 acid c. ability of lipids to react with alcohols c. 18:2 acid and 18:3 acid d. no correct response d. no correct response Quiz 2 Quiz 4 1. Which of the following statements concerning fatty 1. How many structural “subunits” are present in the acids is correct? block diagram for a triacylglycerol? a. They are naturally occurring dicarboxylic acids. a. two b. They are rarely found in the free state in nature. b. three c. They almost always contain an odd number of c. four carbon atoms. d. no correct response d. no correct response 2. How many ester linkages are present in a 2. In which of the following pairs of fatty acids are triacylglycerol molecule? both members of the pair of polyunsaturated fatty a. zero acids? b. two a. 18:0 acid and 18:1 acid c. four b. 18:1 acid and 18:2 acid d. no correct response (three) c. 18:2 acid and 18:3 acid 3. How many different simple triglyceride molecules d. no correct response can be produced that include glycerol, stearic acid, 3. Which of the following fatty acids is an omega-6 and palmitic acid as part of their structure? fatty acid? a. zero a. CH₃ —(CH₂ )₁ ₈ —COOH b. one b. CH₃ —(CH₂ )₇ —CH=CH—(CH₂ )₇ —COOH c. two c. CH₃ —(CH₂ )₄ —CH=CH—(CH₂ )₅ —COOH d. no correct response d. no correct response 4. How many different mixed triglyceride molecules 4. The double bond present in a monounsaturated can be produced that include glycerol, stearic acid, fatty acid almost always and palmitic acid as part of their structure? a. is in a cis-configuration a. two b. three  c. four 2. Triacylglycerol hydrolysis associated with the d. no correct response human digestive process most often produces which 5. Which of the following is a distinguishing of the following? characteristic between fats and oils? a. a diacylglycerol a. physical state at room temperature b. a monoacylglycerol b. number of structural subunits present c. glycerol c. number of fatty acid residues present d. no correct response d. no correct response 6. Unsaturated fatty acid residues are structural 3. Which of the following are the expected products components of when a fat undergoes saponification? a. both fats and oil a. glycerol and fatty acids b. fats but not oils b. glycerol and fatty acid salts c. oils but not fats c. fatty acids and fatty acid salts d. no correct response d. no correct response Quiz 5 4. Unwanted production of trans fats is associated 1. In terms of human body response to dietary fat, with which of the following types of triacylglycerol which of the following is considered to be “good fat”? reactions? a. saturated fats a. saponification b. monounsaturated fats b. hydrogenation c. polyunsaturated fats c. oxidation d. no correct response d. no correct response 2. Current dietary recommendations for Americans, 5. The effect of partial hydrogenation of a fat or oil is relative to omega-3 and omega-6 fatty acids, include which of the following? a recommended increase in a. decrease in the degree of fatty acid unsaturation a. omega-3 fatty acid intake b. decrease in melting point of the fat or oil b. omega-6 fatty acid intake c. increase in the number of fatty acid residues c. both omega-3 and omega-6 fatty acid intake present in a molecule d. no correct response d. no correct response 3. Linolenic acid and linoleic acid, the essential fatty acids, are, respectively, a. 16:1 and 18:1 fatty acids b. 18:1 and 18:2 fatty acids 6. In the oxidation of fats and oils, which structural c. 18:2 and 18:3 fatty acids part of the molecule is attacked by the oxidizing d. no correct response agent? a. carbon–carbon double bonds Quiz 6 b. carbon–carbon single bonds 1. One molecule of a fat or oil, upon complete c. ester linkages hydrolysis, produces how many product molecules? d. no correct response a. two b. three Quiz 7 c. four 1. Based on biological function, phospholipids are d. no correct responses classified as a. energy-storage lipids b. membrane lipids c. messenger lipids  d. no correct response 1. The number of structural building blocks present in a sphingoglycolipid in which a single 2. Which of the following types of lipids contain both monosaccharide unit is present is ester and amide linkages? a. two a. triacylglycerols b. three b. sphingophospholipids c. four c. glycerophospholipids d. no correct response d. no correct response 2. Which of the following types of linkages are 3. Which of the following statements about the always present in a sphingoglycolipid? molecule sphingosine is correct? a. ester linkage and amide linkage a. Two amino groups and one hydroxyl group are b. ester linkage and glycosidic linkage present. c. amide linkage and glycosidic linkage b. Two hydroxyl groups and one amino group are d. no correct response present. c. Two hydroxyl groups and two amino groups are Quiz 9 present. 1. The “steroid nucleus” common to all steroid d. no correct response structures involves a fused-ring system that contains a. four 6-membered rings 4. When the “head and two tails” structural model is b. four 5-membered rings applied to a glycerophospholipid, the two tails are c. three 6-membered rings and one 5-membered a. both fatty acid residues ring b. a fatty acid residue and a phosphate group d. no correct response c. the phosphate group and the glycerol backbone d. no correct response 2. Which of the following types of membrane lipids has a steroid structure? 5. When the “head and two tails” structural model is a. cholesterol applied to a sphingophospholipid, the two tails are b. sphingoglycolipids a. the fatty acid residue and the phosphate group c. sphingophospholipids b. the fatty acid residue and part of the sphingosine d. no correct response molecule c. the phosphate group and part of the sphingosine 3. Which of the following statements concerning molecule cholesterol is correct? d. no correct response a. An alcohol functional group is present in its structure. 6. In terms of the “head and two tails” model for b. The lipoprotein HDL distributes cholesterol to phospholipids various parts of the human body. a. both tails are hydrophobic. c. The cholesterol associated with LDL is often b. both tails are hydrophilic. called “good cholesterol.” c. one tail is hydrophilic and the other hydrophobic. d. no correct response d. no correct response Quiz 10 1. Which of the following is a correct representation for the structure of a lipid bilayer? Quiz 8 c Quiz 12 2. The exterior surface positions in a lipid bilayer are 1. Which of the following statements concerning occupied by steroid hormones is correct? a. hydrophilic entities a. Some, but not all of them, are cholesterol b. hydrophobic entities derivatives. c. nonpolar entities b. Some, but not all of them, are glucose d. no correct response derivatives. c. All of them are cholesterol derivatives. 3. Which of the following polarity-based descriptions d. no correct response is correct for the interior of a lipid bilayer? a. contains “polar heads” 2. Which of the following is a correct pairing of b. contains “nonpolar heads” concepts? c. contains “nonpolar tails” a. pregnancy hormones and estrogens d. no correct response b. female sex hormones and progestins c. male sex hormones and androgens 4. The biochemical function for the cholesterol d. no correct response present in cell membranes is a. impart polarity to the interior membrane b. prevent other membrane components from reacting with each other c. regulate membrane fluidity 3. Which of the following substances is associated d. no correct response with Na+/K+ balance in the human body? a. aldosterone 5. Which of the following membrane transport b. cortisol mechanisms requires both the aid of proteins and the c. prednisolone expenditure of cellular energy? d. no correct response a. facilitated transport b. active transport Quiz 13 c. passive transport 1. The metabolic precursor for the production of most d. no correct response eicosanoids is a. cholesterol Quiz 11 b. arachidonic acid 1. Which of the following statements concerning bile c. sphingosine acids is incorrect? d. no correct response a. They are cholesterol derivatives. b. They are emulsifying agents. 2. Aspirin reduces inflammation and fever by c. They are insoluble in water. inhibiting the formation of which of the following d. no correct response types of messenger lipids? a. prostaglandins 2. Which of the following statements concerning b. thromboxanes structural characteristics of bile acids is correct? c. leukotrienes a. No hydroxyl groups are present. d. no correct response b. Fewer hydroxyl groups are present than in cholesterol. 3. Which of the following types of eicosanoids has a c. More hydroxyl groups are present than in cyclopentane ring as a structural component? cholesterol. a. prostaglandins d. no correct response b. thromboxanes  c. leukotrienes b. Amide linkages are broken. d. no correct response c. Glycosidic linkages are broken. d. no correct response Quiz 14 1. How many structural subunits are present in the NUCLEIC ACIDS "block diagram" for a biological wax? 14:40 a. two Quiz 1 b. three 1. Which of the following statements concerning c. four deoxyribonucleic acids is incorrect? d. no correct response a. They are found in all parts of a cell. b. They are involved in the storage and transfer of 2. Which of the following functional groups is present genetic information. in biological waxes? c. They are passed from existing cells to new cells a. ester during cell division. b. ether d. no correct response c. amide d. no correct response 2. Which of the following statements concerning ribonucleic acids is correct? 3. The number of carbon chains present in the a. They are found primarily within the nucleus of a structures of biological waxes and mineral waxes are, cell. respectively, b. They are directly involved in the synthesis of a. 1 and 1 proteins. b. 2 and 1 c. They are passed from existing cells to new cells c. 2 and 2 during cell division. d. no correct response d. no correct response Quiz 2 1. Any given nucleotide in a nucleic acid contains Quiz 15 a. two pentose sugars, one heterocyclic base, and 1. In which of the following pairs of lipid types are one phosphate group both members of the pair classified as saponifiable b. one pentose sugar, two heterocyclic bases, and lipids? one phosphate group a. triacylglycerols and biological waxes c. one pentose sugar, one heterocyclic base, and b. glycerophospholipids and eicosanoids one phosphate group c. sphingophospholipids and bile acids d. no correct response d. no correct response 2. How many different sugars and how many 2. How many "building blocks" are present in the different heterocyclic bases are available, block diagram structure of a nonsaponifiable lipid? respectively, for incorporation into a nucleotide? a. one a. 2 and 2 b. two b. 2 and 5 c. three c. 3 and 4 d. no correct response d. no correct response 3. Which of the following statements concerning 3. How many different heterocyclic bases that are bond breaking that occurs under saponification purine derivatives are available for incorporation into conditions is incorrect? a nucleotide? a. Ester linkages are broken. a. 2  b. 3 d. no correct answer c. 4 d. no correct response 3. In a segment of a nucleic acid each nonterminal phosphate group Quiz 3 a. carries a 1− charge 1. Which of the following is present in nucleotides but not nucleosides? b. carries a 2− charge a. phosphate group c. carries a 3− charge b. heterocyclic base d. no correct response c. pentose sugar d. no correct response 4. In a segment of a nucleic acid a terminal phosphate group is found at 2. Which of the following is an incorrect statement a. the 3' end of the segment concerning the structural characteristics of a b. the 5' end of the segment nucleotide? c. both ends of the segment a. The phosphate subunit is bonded to the sugar d. no correct response subunit. b. The sugar subunit is bonded to the base subunit. 5. The sequence of bases in a segment of nucleic c. The base subunit is bonded to the phosphate acid subunit. d. no correct response a. is always read in the 5'−to−3' direction b. is always read in the 3'−to−5' direction 3. How many of the eight nucleic acid nucleotides c. can be read in either direction because are found in DNA molecules? directionality does not matter a. four d. no correct response b. five c. all of them d. no correct response 4. The nucleotide AMP is found in a. DNA molecules but not RNA molecules Quiz 5 b. RNA molecules but not DNA molecules 1. Which of the following statements concerning a c. both DNA and RNA molecules DNA double-helix structure is incorrect? d. no correct response a. The two nucleotide strands present are identical. b. Hydrogen bonds help hold the two nucleotide Quiz 4 strands together. 1. The primary structure of a nucleic acid is c. Complementary base pairing occurs within the determined by the sequence of double helix. a. pentoses present d. no correct response b. bases present c. phosphates present 2. Which of the following is the complementary base d. no correct response for C in DNA molecules? a. A 2. The "backbone" of a nucleic acid molecule b. G involves an alternating sequence of c. T a. sugar and phosphate groups d. no correct response b. sugar and base groups c. phosphate and base groups 3. Fifteen percent of the bases in a certain DNA c. occurs at many locations within the double helix molecule are found to be T. What percent of the d. no correct response bases in the same molecule are G? a. 15% 5. A chromosome is a protein–DNA complex that b. 35% contains c. 65% a. a single DNA molecule d. no correct response b. two intertwined DNA molecules c. two structurally independent DNA molecules 4. Which of the following is the correct d. no correct response complementary DNA sequence for the DNA base Quiz 7 sequence 5' C−G−A−A-T−3'? 1. The first phase of protein synthesis is called a. replication a. 5' T−A−A−G−C 3' b. transcription b. 5' G−C−T-T−A 3' c. translation d. no correct response c. 3' G−C−T-T−A 5' d. no correct response 2. The product of the first phase of protein synthesis is Quiz 6 a. DNA molecules 1. Replication of DNA produces two daughter b. RNA molecules molecules in which each daughter molecule contains c. both DNA and RNA molecules a. a segment of both parent strands. d. no correct response b. a segment of both newly synthesized strands. c. one parent strand and one newly synthesized Quiz 8 strand. 1. RNA molecules differ from DNA molecules in that d. no correct response they a. are single stranded rather than double stranded 2. In DNA replication the DNA double helix unwinds b. contain five different bases rather than four under the influence of c. contain a greater number of nucleotide units a. DNA helicase d. no correct response b. DNA polymerase c. DNA ligase 2. The m in the designation mRNA stands for d. no correct response a. mega b. messenger 3. In DNA replication the new strand that is c. monomeric synthesized in small segments is called d. no correct response a. the leading strand b. the lagging strand 3. The t in the designation tRNA stands for c. an Okazaki fragment a. tertiary d. no correct response b. translational c. transfer d. no correct response 4. In DNA replication the unwinding of the DNA double helix a. begins at the 5' end and continues to the 3' end b. begins at the 3' end and continues to the 5' end 4. Which of the following types of RNA is involved in Quiz 10 the transcription phase of protein synthesis? 1. Which of the following statements concerning a. rRNA codons is incorrect? b. tRNA a. They are found within mRNA molecules. c. hnRNA b. They specify base sequence in terms of four- d. no correct response nucleotide units. c. There are 64 of them. Quiz 9 d. no correct response 1. Which of the following statements concerning the transcription phase of protein synthesis is correct? a. A partial unwinding of the DNA double helix occurs. 2. The genetic code is a listing that gives b. The DNA strand used to synthesize RNA is relationships between codons and called the informational strand. a. synonyms c. mRNA molecules are converted to hnRNA b. genes molecules. c. mRNAs d. no correct response d. no correct response 2. What is the complementary hnRNA base 3. Which of the following statements concerning the sequence produced from the DNA base sequence 5' functions for codons is incorrect? C–T–A–T–A–C 3'? a. Each standard amino acid is designated by a a. 3' G–A–U–A–U–G 5' single codon. b. 3' A–U–A–C–G 5' b. Some standard amino acids are designated by c. 3' C–A–U–A–G 5' more than one codon. d. no correct response c. Some codons have a "stop" function rather than an "amino acid" function. 3. The location in a DNA strand carrying the d. no correct response information needed for synthesis of a specific hnRNA molecule is called a 4. Without reference to the genetic code, which of a. gene the following is definitely an incorrect codon–amino b. genome acid pairing? c. chromosome a. UUU–UUC and Phe–Phe d. no correct response b. ACU–AAU and Thr–Asn c. GCC–GCC and Ala–Gly 4. Which of the following types of RNA contains d. no correct response introns and exons? a. hnRNA Quiz 11 b. mRNA 1. Which of the following is an incorrect pairing of c. rRNA concepts? d. no correct response a. tRNA and "amino acid carrier" b. tRNA and "anticodon carrier" 5. Which of the following types of RNA is not part of c. rRNA and "codon carrier" the overall transcription process? d. no correct response a. hnRNA b. mRNA 2. Which of the following statements concerning the c. snRNA "cloverleaf" shape of tRNA molecules is correct? d. no correct response a. Four hairpin loops are present.  b. Three hairpin loops and one open end are c. 4 present. d. no correct response c. Two hairpin loops and two open ends are present. 4. A polyribosome is a complex that d. no correct response a. contains four ribosomal subunits instead of the usual two 3. A tRNA molecule with the anticodon 5' AAG 3' will b. involves a ribosome and several mRNA interact with which of the following mRNA codons? molecules a. 3' AAG 5' c. involves an mRNA molecule and several b. 3' UUC 5' ribosomes c. 5' UUC 3' d. no correct response d. no correct response 5. Which of the following is an activity that does not occur as part of post-translation processing? a. covalent modification through formation of disulfide bonds b. completion of folding of polypeptide chains c. elongation of a polypeptide chain d. no correct response Quiz 13 1. Which of the following describes the effect of a point mutation on amino acid identity in a protein? Quiz 12 a. The identity of one amino acid must change. 1. Which of the following statements about b. The identity of one amino acid may change. ribosomes is correct? c. The identity of two amino acids must change. a. The number of ribosomes in a cell seldom d. no correct response exceeds 50. b. The active site of a ribosome contains mostly 2. Which of the following describes the effect of a protein molecules. frameshift mutation? c. Structurally, ribosomes have two rRNA–protein a. All mRNA codons change. subunits. b. Some, but not all, mRNA codons change. d. no correct response c. There is no change in mRNA codons. d. no correct response 2. Which of the following events is not part of the translation phase of protein synthesis? a. mRNAs carry amino acids to the ribosome active site b. codon–anticodon interactions occur 3. Which of the following statements applies to both c. an mRNA attaches itself to the small subunit of a point and frameshift mutations? ribosome a. A base is removed from a DNA template strand. d. no correct response b. A base is added to a DNA template strand. c. A base is substituted for another base in a DNA 3. The number of codon binding sites in an mRNA– template strand. ribosome complex that can be occupied at the same d. no correct response time by activated tRNA molecules is a. 2 Quiz 14 b. 3 1. Which of the following statements about a virus is 5. The process of inserting recombinant DNA into a correct? host cell is called a. Bacteria are not subject to attack by a virus. a. translocation b. A virus contains both DNA and RNA. b. transformation c. A virus cannot reproduce itself without aid of a c. cloning host cell. d. no correct response d. no correct response Quiz 16 2. Which of the following pairings of concepts is an 1. The polymerase chain reaction is a method for incorrect pairing? rapidly a. vaccine and inactive virus a. producing multiple copies of a DNA base b. DNA-containing virus and retrovirus sequence c. RNA-containing virus and viral DNA b. producing multiple copies of an individual base d. no correct response present in a DNA sequence c. altering base sequence in a DNA segment Quiz 15 d. no correct response 1. The meaning for the lower case r in the designation rDNA is 2. Each cycle of the polymerase chain reaction a. restriction a. doubles the number of product molecules b. recombinant b. produces two new product molecules c. retro c. removes three nucleotides from a reactant DNA d. no correct response molecule d. no correct response 2. Which of the following statements about rDNA is correct? a. It is naturally present in E. coli bacteria. b. It is naturally present in restriction enzymes. c. It contains genetic material from two different organisms. d. no correct response 3. The role of E. coli plasmids in obtaining rDNA is to a. create "sticky ends" on an extracted gene b. activate restriction enzymes c. serve as a host for a "foreign gene" d. no correct response 4. A restriction enzyme is an enzyme that a. prevents formation of rDNA b. produces a straight-across cut in a DNA double helix c. dissolves cell membranes d. no correct response