Week 7, 8, 9
All of the following properties are characteristic of an alcohol with low molecular weight except: A) non-polar B) water soluble C) contains a hydrogen bond donor D) contains a hydrogen bond acceptor E) contains the element oxygen
A
Classify the carbohydrate shown here. A) ketohexose B) ketopentose C) aldohexose D) aldopentose E) aldotetrose
A
Fructose is classified as what type of carbohydrate? A) monosaccharide B) disaccharide C) oligosaccharide D) polysaccharide
A
Galactose is an important monosaccharide found in many disaccharides and polysaccharides Disaccharides that can freely interconvert between the cyclic structure and the straight chain form with an available aldehyde or ketone are called reducing sugars. Choose the best description of this disaccharide, lactose. A) Reducing sugar B) A non-reducing sugar C) Not enough information to tell. D) Oxidizing sugar
A
How does an enzyme catalyze a reaction? A) The enzyme provides an alternative pathway for the reaction that has a lower activation barrier. B) The enzyme provides an alternative pathway for the reaction that has a higher activation barrier. C) The enzyme provides additional energy to surmount the activation barrier. D) The enzyme breaks additional bonds releasing the energy need to get over the activation barrier.
A
In the amino acid shown here, what is the identity of the highlighted unit? A) alpha-carbon B) alpha-carboxyl group C) alpha-amino group D) side chain R-group
A
Monosaccharides containing a carbonyl group on the second carbon are known as _____ A) ketoses B) aldoses C) anomers D) hexoses E) pentoses
A
Name the compound below according to IUPAC rules. A) 5-methylnonane B) isodecane C) 2,2-dibutylethane D) 1,4,7-trimethylheptane E) decane
A
The steroid molecule below is a metabolic precursor of both testosterone and estrone. What functional group(s) are present? A) ketone B) aldehyde C) ether D) ester E) ether and ester
A
The structure shown here is what type of organic formula? A) structural B) skeletal C) line D) condensed
A
This cartoon depicts which type of enzyme inhibition? A) Competitive Inhibition B) Uncompetitive Inhibition C) Noncompetitive Inhibition
A
What classification of protein is described by the following scenario? Actin is a protein found in muscles. A) Contractile B) Storage C) Hormone D) Enzyme E) Protection
A
What is the correct (IUPAC) name for the molecule shown below? A) 2-methylheptane B) 6-methylheptane C) 1,1-dimethylpentane D) isooctane E) 5,5-dimethylpentane
A
What is the formula of 2-methylpropane? A) C₄H₁₀ B) C₃H₈ C) C₃H₁₂ D) C₄H₈ E) C₄H₉
A
What is the name for the region of an enzyme where binding of substrates occurs? A) active site B) binding region C) active region D) specific site E) active area
A
What type of organic compound is CH₃CH₂OCH₂CH₂CH₃? A) ether B) ester C) alcohol D) alkane E) alkene
A
Which compound corresponds to a saturated hydrocarbon? A) 2,4-dimethylhexane B) 2-bromobutane C) 3-pentanol D) 1-propene E) 2-hexyne
A
Which of the following is the correct molecular formula for the molecule below? A) C₅H₁₀ B) C₅H₃ C) C₂H₃ D) C₅H₈ E) None of these are correct
A
Which of the following molecules is a aldehyde? A) Compound A B) Compound B C) Compound C D) Compound D
A
Which of the following statements is true about the quaternary structure of a protein? A) The quaternary structure of a protein is based on how polypeptide subunits interact with one another. B) The quaternary structure of a protein is affected by hydrogen bonds. C) The quaternary structure is the overall shape of a protein. D) The quaternary structure is driven by α-helices and β-pleated sheets. E) The quaternary structure is found in all proteins.
A
Which of these polysaccharides contains β-glycosidic linkages? A) cellulose B) amylose C) amylopectin D) glycogen E) maltose
A
Which type of amino acids comprise proteins? A) alpha B) beta C) gamma D) cis E) trans
A
A carbohydrate containing a chain of four carbon atoms is known as a(n) _____ A) triose B) tetrose C) pentose D) hexose E) quadrose
B
A solution of the amino acid Serine is at pH 1. What will be the overall charge and the charge on the two functional groups? Serine has a pI of 5.68 A) The side groups will be -COO⁻ and -NH₃⁺. Overall the charge will be neutral. B) The side groups will be -COOH and -NH₃⁺. Overall the charge will be positive. C)The side groups will be -COOH and -NH₂. Overall the charge will be neutral. D) The side groups will be -COO⁻ and -NH₂. Overall the charge will be negative. E) The side groups will be -COOH₂⁺ and -NH₂. Overall the charge will be positive.
B
Alkenes contain what type of carbon-carbon bond? A) single bond B) double bond C) triple bond D) aromatic
B
As substrate concentrations increase, enzyme reaction rates ____. However, as substrate concentration becomes very high, enzyme reaction rates ______. A) increase linearly; decrease linearly B) increase; plateau C) increase linearly; increase exponentially D) decrease; increase linearly E) plateau, increase exponentially
B
Classify the molecule below: A) carboxylic acid B) aldehyde C) amine D) ketone E) carbonyl
B
Classify α-cadinene, also known as citronella oil. A) alkene B) diene C) polyene
B
D- and L- designations are used to distinguish between the two possible enantiomers of the monosaccharide, fructose. From the Fischer projection, determine the designation of this monosaccharide. A) D B) L C) D, L D) L, D E) This monosaccharide contains no chiral centers
B
Determine the number of sugar units in a disaccharide. A) 1 B) 2 C) 3 D) 4 E) 10
B
Determine which anomer is represented in the structure shown here. A) alpha B) beta C) gamma D) cis E) trans
B
How do constitutional isomers differ from one another? A) Different types of atoms in the molecule. B) The order in which atoms are bonded to one another. C) The number of hydrogen atoms in the molecules. D) The spatial arrangement of the atoms. E) The molecular formulas used to describe them.
B
How many amino acids are found in natural proteins? A) 10 B) 20 C) 25 D) 50 E) 100
B
How many carbon atoms are present in 2-methylbutane? A) 4 B) 5 C) 6 D) 7 E) 8
B
How many dipeptides can be formed between isoleucine and glutamine? A) 1 B) 2 C) 3 D) 4 E) 5
B
Identify the type of organic compound shown below: A) aldehyde B) ester C) amine D) ketone
B
Lactose is classified as what type of carbohydrate? A) monosaccharide B) disaccharide C) oligosaccharide D) polysaccharide
B
Mimosine is a natural product found in large quantities in the seeds and foliage of some legume plants. What functional groups are present in mimosine? A) carboxylic acid, amine, alkene, ester B) amine, carboxylic acid, ketone, alcohol, alkene C) amine, amide, ketone, carboxylic acid D) alcohol, ketone, amide, alkene E) amine, ether, alcohol, carboxylic acid
B
Monosaccharides containing a carbonyl group on the first carbon are known as _____ A) ketoses B) aldoses C) anomers D) hexoses E) pentoses
B
Name the structure below: A) 2,4-diethylpentane B) 3,5-dimethylheptane C) secondary ethylpentane D) 2,3-dimethyl-2,3-diethylpropane E) None of these
B
Starch, glycogen, and cellulose are examples of what type of saccharides? A) monosaccharides B) polysaccharides C) bisaccharides D) multisaccharides E) disaccharides
B
The common feature of all amides is the presence of a _____ A) C=O group. B) -C(=O)NR₂ group. C) -C(=O)OH group. D) -NH₂ group. E) -SH group.
B
The common functional component of all proteins is a(n) _____ A) sugar backbone. B) amino acid. C) fatty acid chain. D) phosphoester. E) polysaccharide.
B
The compound shown here is classified as what type of organic compound? A) aldehyde B) ketone C) alcohol D) ester E) alkane
B
The compound shown here is classified as what type of organic compound? A) ether B) ester C) alcohol D) ketone E) carboxylic acid
B
The molecule shown here is classified as what type of organic compound? A) alkane B) alkene C) alkyne D) aromatic compound E) aldehyde
B
The representation of a monosaccharide shown here is known as a(n) _____ A) Fischer projection. B) Haworth projection. C) anomeric projection. D) aldose projection. E) ketose projection.
B
This cartoon depicts which type of enzyme inhibition? A) Competitive Inhibition B) Uncompetitive Inhibition C) Noncompetitive Inhibition
B
What is the IUPAC name for the compound shown here? A) 3-ethyl-4-methylpentane B) 3-ethyl-2-methylpentane C) ethylmethylpentane D) 3-ethyl-2-methylhexane E) 2-ethyl-3-methylpentane
B
What is the minimum number amino acids bonded together that defines a protein? A) 3 to 10 B) 20 to 50 C) 100 to 200 D) 400 to 500 E) 1000 to 2000
B
What is the name of the a nonprotein group that is bound to a protein and is required for function? A) cofactor B) prosthetic group C) substrate D) reactant E) coenzyme
B
What molecule is also produced during the formation of a peptide bond? A) Ethanol B) Water C) Ammonia D) Glycine E) Acetic acid
B
What type of interaction holds α-helices and β-pleated sheets together? A) dispersion forces B) hydrogen bonds C) ion-dipole interactions D) disulfide bonds E) London forces
B
What type of linkage bonds monosaccharides together to form disaccharides and polysaccharides? A) anomeric B) glycosidic C) ester D) ether E) hydrogen bond
B
Which of the following best describes how an enzyme lowers the activation energy of a reaction? A) binds substrate in active site B) holds substrate in correct alignment for reaction to occur C) reacts with substrate making it more reactive D) lowers temperature required for reaction to occur E) all of these
B
Which of the following have only a -C-O-C- functional group? A) esters B) ethers C) amines D) aldehydes E) alcohols
B
Which of the following is true concerning the amino acid shown here? A) The pH is below the pI. B) The pH is above the pI. C) The pH has the same value as the pI. D) It is not possible to determine the pH.
B
Which of the following molecules is a ketone? A) Compound A B) Compound B C) Compound C D) Compound D
B
Which of the following molecules is considered unsaturated? A) Compound A B) Compound B C) Compound C D) Compound D
B
Alkanes are generally soluble in what type of solvents? A) aqueous B) polar C) nonpolar D) acidic E) basic
C
All of the following statements about alkene hydrocarbons are true except: A) alkenes contain carbon-carbon double bonds (C=C). B) alkenes that contain only carbon and hydrogen atoms have low water solubility. C) alkene hydrocarbons are polar compounds. D) alkenes undergo addition reactions. E) alkenes can form chains or cyclic structures.
C
Choose the best description of induced fit model of enzyme binding A) The substrate binds in an allosteric site that is perfectly designed to match the shape of the substrate. B) The substrate binds in an allosteric site and induces a change in the shape of the enzyme so that it matches the shape of the substrate. C) The substrate binds in an active site and induces a change in the shape of the enzyme so that it matches the shape of the substrate. D) The substrate binds in an active site that is perfectly designed to match the shape of the substrate.
C
Galactose is an important monosaccharide found in many disaccharides and polysaccharides Galactose can form longer chain carbohydrates. In addition to lactose, human milk contains short chains of alternating glucose and galactose units. A carbohydrate with 2-10 sugar units is considered to be: A) monosaccharide B) disaccharide C) oligosaccharide D) decasaccharide E) polysaccharide
C
Galactose is an important monosaccharide found in many disaccharides and polysaccharides These galactose oligosaccharides resist hydrolysis in the human digestive tract. Choose the best explanation for why these oligosaccharides are not hydrolyzed into the individual monosaccharides. A) The pH of the human digestive tract is not conducive to hydrolysis reactions. B) There is no water in the human digestive tract to enable this hydrolysis reaction. C) Humans lack the correct enzyme to hydrolyze this type of glycosidic linkage. D) Humans cannot digest synthetically made compounds.
C
How does the activity of an enzyme change with an increase in temperature? A) As the temperature increases, the enzyme activity will increase. B) As the temperature increases, the enzyme activity will decrease. C) As the temperature increases, the enzyme activity will increase to a point and then it will abruptly decline. D) As the temperature increases, the enzyme activity remains the same.
C
How many carbon atoms are present in hexane? A) 4 B) 5 C) 6 D) 8 E) 16
C
How many hydrogen atoms are in 4-methyl-2-pentyne? A) 8 B) 9 C) 10 D) 11 E) 12
C
How many hydrogen atoms are present in 2-methylbutane? A) 4 B) 10 C) 12 D) 14 E) 16
C
How many tripeptides can be created from the amino acids glutamine, threonine, and histidine? A) 2 B) 3 C) 6 D) 9 E) 27
C
In the amino acid shown here, what is the identity of the highlighted unit? A) alpha-carbon B) alpha-carboxyl group C) alpha-amino group D) side chain R-group
C
Leucine has a pI of 5.98. At what pH would you expect Leucine to have a negative charge? A) pH values below 5.98 B) 5.98 C) pH values above 5.98 D) Leucine is always neutral overall.
C
Name the following using correct IUPAC nomenclature: A) isopentane B) 2-methylpentane C) 2-methylbutane D) pentane E) 3-methylbutane
C
The bond formed between the carbon of a carbonyl group and the nitrogen of an amine is known as a(n) _____ A) hydrogen bond. B) amine bond. C) amide bond. D) amino bond. E) alkene bond.
C
The common feature of aldehydes and ketones is the presence of a _____ A) -OH group B) -SH group C) C=O group D) double bond E) triple bond
C
The common feature of all carboxylic acids is the presence of a _____ A) C=O group. B) -OH group. C) -C(=O)OH group. D) -C(=O)H group. E) -C(=O)OR group.
C
The compound shown here is classified as what type of organic compound? A) ester B) carboxylic acid C) ketone D) alcohol E) aldehyde
C
The number of covalent bonds carbon forms in organic compounds is ____. A) 2 B) 3 C) 4 D) 5 E) 6
C
What are the two most common forms of secondary structure in proteins? A) alpha-helices and alpha-pleated sheets B) alpha-pleated sheets and beta-helices C) alpha-helices and beta-pleated sheets D) beta-helices and beta-pleated sheets E) beta-helices and alpha-pleated sheets
C
What is the N-terminal amino acid in the tripeptide: Glu-Pro-Gly? A) Proline B) Glycine C) Glutamic Acid D) Glutamine E) Phenylalanine
C
What is the charge of a zwitterion? A) negative B) positive C) neutral D) charge depends on the pH
C
What is the formula of an alkane with 18 carbon atoms? A) C₁₈H₁₈ B) C₁₈H₃₆ C) C₁₈H₃₈ D) C₁₈H₄₀ E) C₁₈H₅₄
C
What is the name of the alkane with the formula CH₃CH₂CH₂CH₂CH₃? A) propane B) butane C) pentane D) hexane E) heptane
C
What monosaccharide is the monomer in starch, glycogen, and cellulose? A) sucrose B) fructose C) glucose D) galactose E) lactose
C
What type of functionality does phenol contain besides the aromatic ring? A) amino B) alkene C) hydroxy D) alkyl E) aldehyde
C
When substrate concentrations are very high, the enzyme reaches it maximum turnover rate. The enzyme active sites are all filled with substrate and the enzyme is considered to be at _______. A) catalytic efficiency B) equilibrium C) saturation D) turnover rates
C
Which carbon is the anomeric carbon in the structure shown here? A) A B) B C) C D) D E) E
C
Which of the following formulas correspond to that of a straight-chain alkane? A) C₇H₁₄ B) C₅H₁₀ C) C₄H₁₀ D) C₆H₁₀
C
Which of the following is not a method of denaturing a protein? A) heat B) acidic solution C) concentration D) presence of heavy metals E) mechanical stress
C
Which of the following levels of structure do all proteins have? A) primary B) primary and secondary C) primary, secondary, and tertiary D) secondary and tertiary E) primary, secondary, tertiary, and quaternary
C
Which of the following molecules is a carboxylic acid? A) Compound A B) Compound B C) Compound C D) Compound D
C
Which of the following molecules is an amide? A) Compound A B) Compound B C) Compound C D) Compound D
C
Which of the following properties is associated with the alkane octane? A) non-flammable liquid B) polar C) low water solubility D) density greater than water E) hydrogen bonding
C
A solution of the amino acid Glycine is at pH 13. What will be the overall charge and the charge on the two functional groups? Glycine has a pI of 5.97 A) The side groups will be -COO⁻ and -NH₃⁺. Overall the charge will be neutral. B) The side groups will be -COOH and -NH₃⁺. Overall the charge will be positive. C)The side groups will be -COOH and -NH₂. Overall the charge will be neutral. D) The side groups will be -COO⁻ and -NH₂. Overall the charge will be negative. E) The side groups will be -COOH₂⁺ and -NH₂. Overall the charge will be positive.
D
Because compounds containing a double bond have fewer hydrogens than their corresponding alkanes, they are classified as: A) acyclic B) cyclic C) saturated D) unsaturated
D
Choose the best description of how a substrate binds to an enzyme active site. A) The substrate binds covalently to the active site. B) The substrate binds to the active site if its geometry and shape fit the geometry of the active site. C) The substrate binds to the active site if there are strong enough intermolecular forces attracting the substrate to the active site. D) The substrate binds to the active site if the geometry fits and there are sufficient intermolecular forces attracting the substrate to the active site.
D
Choose the best description of lock-and-key model of enzyme binding A) The substrate binds in an allosteric site that is perfectly designed to match the shape of the substrate. B) The substrate binds in an allosteric site and induces a change in the shape of the enzyme so that it matches the shape of the substrate. C) The substrate binds in an active site and induces a change in the shape of the enzyme so that it matches the shape of the substrate. D) The substrate binds in an active site that is perfectly designed to match the shape of the substrate.
D
Galactose is an important monosaccharide found in many disaccharides and polysaccharides Disaccharides are described by the position of the anomeric carbon and the numbering of the atoms involved in the glycosidic bond. Identify the type of glycosidic linkage present in lactose, the disaccharide found in milk. A) α-1,2 B) α-1,4 C) β-1,2 D) β-1,4 E) β-1,6
D
Galactose is an important monosaccharide found in many disaccharides and polysaccharides Lactose in milk is hydrolyzed, absorbed through the intestines, and then utilized for energy metabolism. Oligosaccharides that are not hydrolyzed in the digestive tract cannot be absorbed nor used for energy. Choose the best explanation for why these oligosaccharides would be necessary in human milk (or infant formula). A) These oligosaccharides prevent weight gain in infants. B) These oligosaccharides absorb excess energy, allowing infants to sleep. C) These oligosaccharides train the digestive tract to tolerate high levels of sugars, necessary for a typical adult American diet. D) These oligosaccharides provide fiber and prevent constipation.
D
Galactose is an important monosaccharide found in many disaccharides and polysaccharides To mimic components of human milk, scientists have produced galactose oligosaccharides. These oligosaccharides are used in infant formula. Identify the type of glycosidic linkage present in the galactose oligosaccharide shown. A) α-1,2 B) α-1,4 C) β-1,2 D) β-1,4 E) β-1,6
D
How many carbon atoms are present in benzene? A) 3 B) 4 C) 5 D) 6 E) 7
D
How many carbons atoms are represented in the skeletal structure shown here? A) 3 B) 4 C) 5 D) 6 E) 7
D
How many hydrogen atoms are present in a straight-chain alkane with 11 carbon atoms? A) 11 B) 20 C) 22 D) 24 E) 33
D
Identify the number of carbon atoms in the carbohydrate glucose. A) 3 B) 4 C) 5 D) 6 E) 7
D
In what form is glucose stored in animals? A) cellulose B) amylose C) amylopectin D) glycogen E) maltose
D
In which of the following lists do all members have a C=O bond? A) ester, aldehyde, amine, ketone B) thiol, ether, ester C) haloalkane, ketone, aldehyde D) ester, aldehyde, ketone E) carboxylic acid, ether, alcohol
D
Isomers have ______________ A) different molecular formulas and different structures. B) different molecular formulas but the same structure. C) the same molecular formula and the same structure. D) the same molecular formula but different structures. E) None of these.
D
None of the following elements are present in an alcohol except: A) S B) Na C) Br D) O E) N
D
Saturated hydrocarbons never contain ______ A) single bonds. B) single and double bonds. C) single and triple bonds. D) double and triple bonds. E) single, double, and triple bonds.
D
Subunits of insulin are held together with disulfide bonds. What level of protein structure does this represent? A) Primary B) Secondary C) Tertiary D) Quaternary E) All levels of protein structure
D
The common feature of all amines is the presence of a _____ A) C=O group. B) -OH group. C) -C(=O)OH group. D) -NH2 group. E) -SH group.
D
The compound shown here is what type of organic compound? A) alkane B) alkene C) alkyne D) aromatic compound E) aldehyde
D
The enzyme lactase breaks down lactose into glucose and galactose. The presence of glucose can be qualitatively measured with paper testing strips that turn color to indicate the presence of glucose. The testing strip will change color to purple to indicate glucose is present. If glucose is not present, the testing strip will stay white. In lab, a student heats a sample of the enzyme lactase to 100°C. Next, the lactase is added to a solution of lactose. The student then uses a testing strip to indicate if glucose is present. What should they expect to find and why? A) The strip should be bright purple, because glucose was produced. The heating will speed up the chemical reaction. B) The strip will be purple, because glucose was produced. The heating will have no effect. C) The strip will be light purple, because some glucose was produced. The heating will denature lactase, but it will still work. D) The strip will be white, because no glucose will be produced. The heating will denature lactase, and it will no longer function. E) The strip will be white, because glucose was produced. The heating had no effect.
D
What are the two types of secondary structures? A) α-pleated sheets and β-helices B) double helices C) α-helices and β-helices D) α-helices and β-pleated sheets E) α-pleated sheets and β-pleated sheets
D
What is the main source of glucose in plants? A) gluconeogenesis B) glycogen C) Glycolysis D) photosynthesis E) gluconic acid metabolism
D
What type of bond joins amino acids into proteins? A) glycosidic bond B) hydrogen bond C) ester bond D) amide bond
D
Which of the following formulas matches that of a straight-chain alkane? A) C₈H₁₆ B) C₉H₁₈ C) C₁₀H₂₀ D) C₁₁H₂₄
D
Which of the following formulas represents an organic compound? A) KCl B) NH₃ C) Cl₂ D) C₃H₈ E) SiH₄
D
Which of the following is the correct IUPAC name for a structural (constitutional) isomer of pentane? A) I only B) I and II only C) I and III only D) II only E) I, II, and III
D
Which of the following molecules is an ester? A) Compound A B) Compound B C) Compound C D) Compound D
D
Which of the following molecules is aromatic? A) Compound A B) Compound B C) Compound C D) Compound D
D
Cellulose is a polysaccharide commonly found in what biological structures? A) animals cells B) hair C) tissues D) bone E) cell wall of plants
E
In sickle cell anemia the 6th amino acid is changed from glutamic acid to valine in the protein hemoglobin. Which level(s) of protein structure could be affected? A) Primary B) Secondary C) Tertiary D) Secondary and Tertiary E) Primary, Secondary, and Tertiary
E
The amino acid structure shown here is known as a(n) _____ A) primary structure. B) secondary structure. C) C-terminus. D) N-terminus. E) zwitterion.
E
The common feature of all esters is the presence of a _____ A) C=O group. B) -OH group. C) -C(=O)OH group. D) -C(=O)H group. E) -C(=O)OR group.
E
The compound shown here is classified as what type of organic compound? A) aldehyde B) ketone C) alcohol D) ester E) carboxylic acid
E
What classification of protein is described by the following scenario? Antibodies bind to pathogens and label them as foreign substances. A) Contractile B) Transport C) Hormone D) Enzyme E) Protection
E
What is the IUPAC name for the compound below? A) 4-ethyl-5-ethyl-5-methylheptane B) 4,5-diethyl-5-methylheptane C) 3,4-dimethyl-5-ethyloctane D) 4-ethyl-5,6-dimethyloctane E) 5-ethyl-3,4-dimethyloctane
E
What is the relationship between the two molecules shown below? A) They are identical. B) They are constitutional isomers. C) They are isotopes. D) They are enantiomers. E) They are not isomers.
E
What two letters are used to designate the stereochemistry of an amino acid? A) R and S B) D and R C) R and L D) S and D E) D and L
E