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Day 1 Biochemical Engineering Glucose and fructose are examples of A. double sugars B. disaccharides C. single sugars D. polysaccharides (CH2O)n is the molecular formula for which type of macromolecules? A. Proteins B. Lipids C. Carbohydrates D. Nucleic Acid Which of the following is NOT a polysaccharide? A. Glycogen B. Starch C. Sucrose D. Cellulose What are used in animals as a source of quick energy that can be stored in the liver and muscles ？ A. Proteins B. Nucleic acids C. Carbohydrates D. Lipids Sugars, starches, and cellulose belong to which Major class of biological molecules? A. Nucleic acids B. carbohydrates C. lipids D. polypeptides Plants like sugar cane and sugar beets store the energy simple sugars. Other plants, like corn and potatoes, store the energy as more complex sugars called? A. carbohydrates B. calories C. starches D. cellulose Which macromolecule does not dissolve in water? A. proteins B. lipids C. carbohydrates D. nucleic acids Monosaccharides have yellow appearance and are solublein water. True or False? A. True, they are yellow and soluble in water. B. False, they are yellow and are insoluble in water C. False, they are colorless and are soluble in water D. False, they are colorless and insoluble in water. What are the monomers of lipids? A. Amino acids B. Simple sugars C. Fatty acids and glycerol D. Nucleic acids Lipids are used by the body to perform all of the following functions EXCEPT: A. membrane structural material. B. enzyme action. C. insulation. D. a rich energy source. What type of organic substances are fats? A. nucleic acid B. carbohydrate C. protein D. lipids Fats that have fatty acids with only single covalent bonds in their carbon skeletons are A. saturated B. unsaturated C. found in plants instead of animals D. liquid at room temperature Which has the higher melting point: (a) a triglyceride containing only lauric acid and glycerol or (b) a triglyceride containing only stearic acid and glycerol? A. (a) B. (b) C. Both have equal melting points D. None of the above Which of the following is a polymer? A. nucleic acid B. fatty acid C. Amino acid D. Glycerol This biological macromolecule is responsible for controlling the activity of the cell, and it stores and transports genetic information. A. Carbohydrate B. Nucleic acid C. Water D. Glucose
What are described as the "building blocks of Protein"? A. Fiber B. Lipids C. Amino Acids D. Nutrients Proteins are made of amino acid. A. monomers; polymers B. polymers; polypeptides C. polymers; monomers D. monomers; molecules In this type of structure, most of carbonyl groups of peptide bonds forms a hydrogen bond with the amide nitrogen of another peptide bond four amino acids further down the polypeptide chain: A. Alpha-helix B. Beta-sheet C. Beta-turn D. Quaternary The isoelectric point of an amino acid is defined as the pH A. where the molecule carries no electric charge B. where the carboxyl group is uncharged C. where the amino group is uncharged D. of maximum electrolytic mobility When the amino acid alanine (Rgroup is CH3) is added to a solution with a pH of 7.3, alanine becomes A. a cation B. nonpolar C. a zwitterions D. an anion The term “SALTING IN” refers to? A.Changes in an amino acid’s isoelectric point. B.Increasing the solubility of a protein in solution by adding ions. C.The use of a liquid bridge in an electrochemical cell. D. The ionization of a strong acid. The local spatial arrangement of a polypeptide’s backbone atoms without regard to the conformation of its side chains can be called as A. Primary structure B. Secondary structure C. Tertiary structure D. Quaternary structure Which of the following amino acids are more likely to be found in a protein’s interior away from aqueous solvent molecules? A. Val, Leu, Ile, Met, and Phe B. Ser, Thr, Asn, Gln, and Tyr C. Arg, His, Lys, Asp, and Glu D. All of the above. Which of the following is (are) true of - turns in proteins? A. It is a 180º turn of four amino acids. B. Glycine and proline are frequently found there. C. Are used as connecting turns of - helix D. All of the above. The primary stabilizing force of protein secondary structure is: Ionic bonds. Covalent bonds. Van der Waals forces. Hydrogen bonds Two types of -pleated sheets can be called:. parallel and antiparallel left-handed and right-handed. and αand β Which of the following is NOT a characteristic of a globular protein? A. Polypeptide chain in extended, long sheets
What is the role of hydrogen bonds in the structure if DNA? A. to code for proteins B. to synthesize proteins C. to separate the strands D. to connect the base pairs Nucleoside is a pyrimidine or purine base A.covalently bonded to a sugar B.ionically bonded to a sugar C.hydrogen bonded to a sugar D.none of the above The sugar in RNA is , the sugar in DNA is A.deoxyribose, ribose B.ribose, deoxyribose C.ribose, phosphate D.ribose, uracil In gel electrophoresis, what fragments will move most quickly through a gel? A.Large fragments B.Small fragments C.Large genome D.None of these Nucleotide bases and aromatic amino acids absorb light respectively at A.280 and 260 nm B.260 and 280 nm C.270 and 280 nm D.260 and 270 nm Which of the following is found on RNA but not DNA? A.Uracil B.Deoxyribose C.Phosphate D.Adenine Which is true about the pairing of bases in the DNA molecule? A. purines always pair with pyrimidines B. a single ring base pairs with another single ring base C. a double ring base pairs with another double ring base D. purines pair with purines and pyrimidines with pyrimidines The messenger acid is 336 nucleotides long, including the initiator and termination codons. The maximum number of amino acids in the protein translated from this mRNA is: A. 999 B. 630 C. 330 D. 111 E. 110 With what mRNA codon would the tRNA in the diagram be able to form a codon-anticodon base pairing interaction? A. 3'-AUG-5' B. 3'-GUA-5' C. 3'-CAU-5' D. 3'-UAC-5' E. 3'-UAG-5' What is the function of enzymes within living systems? A) structural elements B) neurotransmitters C) catalysts D) hormones Enzymes have names that A) always end in -ase B) always end in -in C) can end either in -in or -ase D) can end in either -in or -ogen The protein portion of a conjugated enzyme is called a(n) A) apoenzyme. B) coenzyme. C) holoenzyme. D) cofactor.
Which of the following could be a component of a conjugated enzyme? A) coenzyme B) cofactor C) apoenzyme D) more than one correct response E) no correct response Enzyme cofactors that bind covalently at the active site of an enzyme are referred to as. (a) cosubstrates. (b) prosthetic groups. (c) apoenzymes. (d) vitamins Which of the following statements concerning the effect of temperature change on an enzyme-catalyzed reaction is correct? A. An increase in temperature can stop the reaction bydenaturing the enzyme. B. An increase in temperature can increase the reaction rate by increasing the speed at which molecules move. C. An increase in temperature to the optimum temperature maximizes reaction rate. D. more than one correct response E. no correct response `A catalyst can promote product formation during a chemical reaction by. (a) lowering the activation energy barrier. (b) stabilizing the transition state. (c) positioning reactants in the correct orientation. (d) bringing reactants together. (e) all of the above Which of the following is characteristic of an enzyme catalyst? (a) It positions reactants in the correct orientation. (b) It lowers the activation energy barrier. (c) It binds the transition state tighter than the substrate. (d) all of the above An enzyme active site is the location in the enzyme where A) protein side groups are brought together by bending and folding to form a site for interactions with substrates B) the catalyst interactions with the enzyme C) catalyst molecules are generated D) the substrate creates the catalyst molecules An enzyme active site is the location in an enzyme where substrate molecules A) are generated. B) become catalysts. C) undergo change. D) more than one correct response E) no correct response For the enzyme reaction A+ B = C + D, Delta Go ' = + 1 kcal/mol. This reaction will proceed spontaneously in aforward direction if: A. The concentration of C is increased one-hundred fold B. The concentration of A is increased one-hundred fold C. The concentration of B is lowered one-hundred fold D.The concentration of both A and D are increased onehundred fold Which of the following statements about enzymes or their function is true? A.Enzymes do not alter the overall change in free energy for a reaction B. Enzymes are proteins whose three-dimensional formis key to their function C.Enzymes speed up reactions by lowering activation energy D. All of the above What is the optimal temperature range for the majority of enzymes? A. 40-55 ℃ B. 35-40 ℃ C. 25-30 ℃ D. 15-20 ℃
The rate-determining step of Michaelis Menten kinetics is A.the complex formation step B.the complex dissociation step to produce product C.the product formation step D.Both (a)and(c) A competitive inhibitor of an enzyme works by A. fitting into the enzyme's active site B. fitting into the allosteric site of the enzyme C.attaching itself to the substrate, thereby preventing the enzyme from making contact with substrate D.increasing the activation energy of the enzymecatalyzed reaction If an enzyme is described by the MichaelisMenten equation, a competitive inhibitor will: A. decrease the Km and decrease the Vmax B. decrease the Km, but not the Vmax C. always just change the Vmax D. increase the Km but not change the Vmax The most likely effect of a non-competitive inhibitor on an Michaelis-Menten enzyme is to A. Increase the Vmax B. Decrease the Vmax C. Increase both the Vmax and the Km D. Decrease both the Vmax and the Km Which of the following binds to an enzyme at its activesite? A) irreversible inhibitor B) reversible competitive inhibitor C) reversible noncompetitive inhibitor D) more than one correct response E) no correct response An uncompetitive inhibitor binds to. (a) E (b) ES (c) P (d) a and b (e) a and c Reversible inhibitor that can bind to either E alone or the ES complexis referred to as a. (a) competitive inhibitor. (b) non-competitive inhibitor. (c) uncompetitive inhibitor. (d) suicide inhibitor. (e) irreversible inhibitor. A competitive inhibitor of an enzyme is usually A. a highly reactive compound B. a metal ion such as Hg2+or Pb2+ C. structurally similar to the substrate. D. water insoluble The enzyme inhibition can occur by A. reversible inhibitors B. irreversible inhibitors C. Both (a) and (b) D. None of thes In a Lineweaver-Burk Plot, competitive inhibitor shows which of the following effect? A. It moves the entire curve to right B. It moves the entire curve to left C. It changes the x-intercept D. It has no effect on the slope Non-competitive inhibitor of an enzyme catalyzedreaction A.decreases Vmax B.binds to ES C.both (a) and (b) D.can actually increase reaction velocity in rare Cases A classical uncompetitive inhibitor is a compound that binds A. reversibly to the enzyme substrate complex yielding an inactive ESI complex B. irreversibly to the enzyme substrate complex yielding an inactive ESI complex C. reversibly to the enzyme substrate complex yielding an active ESI complex
D. irreversibly to the enzyme substrate complex yielding an active ESI complex Two curves showing the rate versus substrate concentration are shown below for an enzyme‐ catalyzed reaction. One curve is for the reaction in the presence of substance X. The other curve is for data in the absence of substance X.Examine the curves and tell which statement below is true. A) The catalysis shows Michaelis‐Menten kinetics with or without X. B) X increases the activation energy for the catalytic reaction. C) X could be a competitive inhibitor. D) X is an activator of the enzyme. Allosteric modulators seldom resemble the substrate or product of the enzyme. What does this observation show? A) Modulators likely bind at a site other than the active site. B) Modulators always act as activators. C) Modulators bind non-covalently to the enzyme. D) The enzyme catalyzes more than one reaction. Some enzymatic regulation is allosteric. In such cases, which of the following would usually be found? A) cooperativity B) feedback inhibition C) both activating and inhibitory activity D) an enzyme with more than one subunit E) the need for cofactors How many moles of lactate are produced from 3 moles of glucose A. 2 B. 4 C. 6 D. 8 Glycolytic pathway regulation involves A. allosteric stimulation by ADP B. allosteric inhibition by ATP C. feedback, or product, inhibition by ATP D. all of the above Why does the glycolytic pathway continue in the direction of glucose catabolism? A. There are essentially three irreversible reactions that act as the driving force for the pathway B. High levels of ATP keep the pathway going in a forward direction C. The enzymes of glycolysis only function in one direction D. Glycolysis occurs in either direction The released energy obtained by oxidation of glucose is stored as A. a concentration gradient across a membrane B. ADP C. ATP D. NAD+ For every one molecule of sugar glucose which is oxidized molecule of pyruvic acid are produced. A. B. C. D. The enzymes of glycolysis in a eukaryotic cell are located in the A.intermembrane space B.plasma membrane C.cytosol D.mitochondrial matrix Which of the following is not true of glycolysis? A.ADP is phosphorylated to ATP via substrate level phosphorylation B.The pathway does not require oxygen C.The pathway oxidizes two moles of NADH to NAD+ for each mole of glucose that enters D.The pathway requires two moles of ATP to get started catabolizing each mole of glucose
D.Glycolysis or gluconeogenesis cannot be active at the same time. If they were is would be a futile cycle In the liver, glucagon will activate A. Glycolysis and glycogen synthesis B. Gluconeogenesis and glycogenolysis C. Gluconeogenesis and glycogen synthase D. Gluconeogenesis and glycogen synthesis Which of the following statements about hormonal levels during different states is true? A. During the time you are eating a high carbohydrate mixed meal, the insulin to glucagon ratio will decrease B. When passing from the fed to fasting state, insulin and glucagon usually decrease C. When playing basketball, epinephrine is usually low and insulin is high D. After running for 20 miles, epinephrine and glucagon are high and insulin is low All of the following will result in activation of glycogen phosphorylase in skeletal muscle EXCEPT A.Increased concentrations of AMP from contraction of muscle B. Increased epinephrine and cAMP C. Increased cytosolic [Ca++] D. Increased protein phosphatase E. Increased activity of glycogen phosphorylase kinase A biological redox reaction always involves A.an oxidizing agent B.a gain of electrons C.a reducing agent D.all of these Coenzyme Q is involved in electron transport as A.directly to O B.a water-soluble electron donor C.covalently attached cytochrome cofactor D.a lipid-soluble electron carrier FAD is reduced to FADH2during A. electron transport phosphorylation B. lactate fermentation C. Krebs cycle D. glycolysis During glycolysis, electrons removed from glucose are passed to A. FAD B. NAD+ C. acetyl CoA D. pyruvic acid Almost all of the oxygen (O2) one consumes in breathing is converted to: A.acetyl-CoA. B.carbon dioxide (CO2). C.carbon monoxide and then to carbon dioxide. D.water. The carbon dioxide is primary a product of A.Krebs cycle B.glycolysis C.electron transport phosphorylation. D.lactate fermentation. Cellular respiration takes place mostly in: A. chloroplasts B. ribosomes C. nucleus D. mitochondria Which of the following is not present during the TCA cycle? A. NADH B. O C. CO D. ATP Which of the following is a list of the stages in the correct order? A.pyruvate oxidation, glyocolysis, the citric acid cycle, and oxidative phosphorylation B.oxidative phosphorylation, glyocolysis, the citric acid cycle, and pyruvate oxidation
C. glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation D.glycolysis, the citric acid cycle, pyruvate oxidation, and oxidative phosphorylation What are the products of the citric acid cycle? A. NADH, ATP, FADH2, and CO B. O2, ADP, 1 FAD, and NAD+ C. Glucose, ATP, O2, and NADH D. heat, H2O, NADH, and pyruvate Which of the following is NOT a way of producing ATP in humans? A. Krebs Cycle B. Alcohol Fermentation C. Lactic Acid Fermentation D. Glycolysis Which of the following is an aerobic product of pyruvate catabolicmetabolism? A. lactate B. ethanol C. acetyl CoA D. glucose The TCA cycle: A. Is found in the cytosol B.Is controlled by the ADP/ATP ratio and the NADH concentration C. Is also called the Cori cycle D. Produces most of the water made in humans The Krebs Cycle begins when pyruvic acid produced by glycolsis enters the A. cytosol B. air C. mitochondrion D. nuclea In aerobic organisms growing in the presence of oxygen, the NADH produced by glycolysis ultimately donates its high-energy electrons to. A.electron transport chains in the mitochondria B. ATP C. pyruvate D. glucose Cellular respiration takes place mostly in: A. chloroplasts B. ribosomes C. nucleus D. mitochondria The main purpose of the electron transport chain is to: A.Use high energy electrons from other cycles to convert ADP into ATP B.Maintain a stable balance of high energy electrons C. Constantly distribute electrons throughout the cell D.Tell the cell when glycolysis should stop or start Oxidative phosphorylation: A. Is anaerobic B. Requires AMP C. Requires the electron transport system D.Is not dependent upon development of a proton gradient ‘ Where are the proteins of the electron transport chain located? A. cytosol B. mitochondrial outer membrane C. mitochondrial inner membrane D. mitochondrial matrix The ATP synthase responsible for most of the ATP synthesis in the body is located: A.On the outer side of the outer mitochondria membrane B.On the inner side of the outer mitochondria membrane C. On the outer side of the inner mitochondria membrane D.On the inner side of the inner mitochondria membrane In the electron transport chain, the final electron acceptor is A. oxygen B. a molecule of carbon dioxide
B. excision repair C. mismatch repair D. none of these Proofreading activity to maintain the fidelity of DNA synthesis A. occurs after the synthesis has been completed B. is a function of the 3'-5' exonuclease activity of the DNA polymerases C. requires the presence of an enzyme separate from the DNA polymerases D. occurs in prokaryotes but not eukaryotes Which of the following repairs nicked DNA by forming a phosphodiester bond between adjacent nucleotides? A. Helicase B. DNA gyrase C. Topoisomerases D. DNA ligase The replication of chromosomes by eukaryotes occurs in a relatively short period of time because A. the eukaryotes have more amount of DNA for replication B. the eukaryotic replication machinery is 1000 times faster than the prokaryotes C. each chromosome contains multiple replicons D. eukaryotic DNA is always single stranded During which of the following process a new copy of a DNA molecule is precisely synthesized? A. Trasformation B. Transcription C. Translation D. Replication Which of the following enzyme adds complementary bases during replication? A. Helicase B. Synthesase C. Replicase D. Polymerase Which of the following enzymes unwind short stretches of DNA helix immediately ahead of a replication fork? A. DNA polymerases B. Helicases C. Single-stranded binding proteins D. Topoisomerases Which DNA polymerase removes RNA primers in DNA synthesis? A. Polymerase I B. Polymerase II C. Polymerase III D. none of these Enzyme, responsible for proofreading base pairing is A. DNA polymerase B. Telomerase C. Primase D. DNA ligase A helicase is used to A. unwind the double helix B. interact the double helix closely C. break a phosphodiester bond in DNA strand D. none of the above The synthesis of DNA by DNA polymerase occurs in the A. 3' to 5' direction B. 5' to 5' direction C. 5' to 3' direction D. 3' to 3' direction The 5' and 3' numbers are related to the A. length of the DNA strand B. carbon number in sugar C. the number of phosphates D. the base pair rule What is the main damaging effect of UV radiation on DNA? A. Depurination B. Formation of thymine dimers
C. Single strand break D. Dehydration Which of the following enzyme is used for synthesis of RNA under the direction of DNA? A. RNA polymerase B. DNA ligase C. DNA polymerase D. RNA ligase Which of the following is a product of transcription? A. mRNA B. tRNA C. rRNA D. all of these Recognition/binding site of RNA polymerase is called A. receptor B. promoter C. facilitator D. terminator An mRNA transcript of a gene contains A. a start codon B. a stop codon C. a terminator D. all of these Where in the cell is the DNA transcribed into mRNA? A.Cytoplasm B.Nucleus C.Golgi D.Cell cytoskeleton Since the two strands of the DNA molecule are complementary, for any given gene: A. The RNA polymerase can bind to either strand. B.Only one strand actually carries the genetic code for a particular gene. C.Each gene possesses an exact replica so that no mutation occurs. D.A gene transcribed in the 5’ to 3’ direction on one strand can be transcribed in the 3’ to 5’ direction on the other strand. The site of protein synthesis is A. Ribosome B. Nucleus C. Endoplasmic reticulum D. Chromosome The structure in a bacterium that indicates an active site for protein synthesis is A. a chromosome. B. a cell membrane, C. a flagellum. D. a polysome. Which of the following is not necessary for protein synthesis to occur, once transcription is completed? A. tRNA B. Ribosomes C. mRNA D. DNA During the process of translation: A.the peptide is ‘passed’ from the tRNA in the P-site to the tRNA in the A-site. B. incoming tRNAs must first bind to the E-site. C.initiation begins with the binding of the ribosomal SSU to the poly-A tail of the mRNA. D. the mRNA is translated by one ribosome at a time. The nucleolus of the nucleus is the site where: A. RNA processing occurs B.rRNA is transcribed and ribosomal subunits are assembled C. tRNA are charged with amino acids
