C785 Biochemistry preassessment Exam with 100% Correct Answers 2023

Assuming 100% reaction efficiency, how many DNA copies are created after the completion of four complete PCR cycles? - Correct answer-16 What is the function of DNA polymerase in the process of PCR? - Correct answer-It recognizes the primers and uses the available dNTPs to replicate the template DNA sequence. What are possible blood types of the parents of a patient with blood type AB? - Correct answer-A and B − Amino Acid Number Tyr Gly Thr Pro − Amino Acid Sequence TAC GGG ACA CCA − DNA Sequence What is the amino acid in position 118 that results from a single nucleotide insertion immediately following the three guanines that encode for glycine 116? - Correct answerThr In sickle-cell disease, the glutamic acid (Glu) at position number seven is mutated to valine (Val). What change in codons corresponds to this mutation? - Correct answer-GAA to GTA Which type of mammalian DNA damage repair requires the presence of the chromosome that is homologous to the damaged chromosome? - Correct answerRecombination Xeroderma pigmentosum (XP) is a recessive genetic disease that occurs when one or more of the genes that perform nucleotide excision repair are nonfunctional. Why do XP patients have a much higher incidence of skin cancer than the general population? - Correct answer-The mutation rate of all other genes is higher due to failure to repair. Which mRNA sequence results in a polypeptide that contains three amino acids? - Correct answer-5' - CUU GAU ACU UAG - 3' Which template strand DNA sequence would result in the amino acid (Ser)? - Correct answer-5' - CGA - 3' What is the complementary sequence for the following DNA sequence? 5' - GCC ATC TCG AAT - 3' - Correct answer-5' - ATT CGA GAT GGC - 3' Studies have shown that increased expression of two genes called SIRT1 and SIRT2 is associated with chronic exposure to cocaine and contributes to drug addiction. What difference in the regions of the SIRT1 and SIRT2 genes in people addicted to cocaine increases their expression? - Correct answer-The nucleosomes become more widely spaced. What occurs during the process of alternative splicing of mRNA? - Correct answerAlternate combinations of exons within the same gene are linked together. Which force is most influential in determining the tertiary structure of a protein? - Correct answer-Hydrophobic effect Given the following amino acid structure, what is the strongest intermolecular force it would participate in to stabilize a protein structure? - Correct answer-Hydrogen bond What is the name of large, functional protein structures composed of smaller proteins with multiple subunits - Correct answer-Quaternary structure Which structural level shows the greatest difference when replacing denatured proteins with a denatured single subunit protein? - Correct answer-Tertiary Which level of protein structure is established through the dehydration synthesis of peptide bonds? - Correct answer-primary Which situation would most likely lead to a permanent alteration of protein function? - Correct answer-A mutation that substitutes a hydrophobic amino acid with a hydrophilic amino acid Given the following amino acid structure, what is the strongest intermolecular force it would participate in to stabilize a protein structure? - Correct answer-hydrogen bond What is the name of large, functional protein structures composed of smaller proteins with multiple subunits? - Correct answer-quarternary structure Pepsin, the enzyme that catalyzes the breaking of peptide bonds, has the highest activity in the acidic environment of the stomach. What process is disrupted after a patient ingests excessive antacid that neutralizes the pH of the stomach? - Correct answer-Protein catabolism An active elderly patient is becoming frequently disoriented, having trouble recalling her daily routine, and becoming aggravated easily. She forgets words and places and has difficulty recognizing her children. Which biochemical event is responsible for this patient's behavior? - Correct answerProtein aggregation In which situation would altering a protein structure lead to a disease state? - Correct answer-A mutation in aconitase blocks an essential step in aerobic metabolism How does hemoglobin keep blood pH neutral during exercise? - Correct answerDeoxygenated hemoglobin binds to excess H +. What is occurring in surrounding tissues as the amount of hemoglobin saturated with oxygen increases? - Correct answer-The amount of carbon dioxide decreases. What is occurring in surrounding tissues as the amount of hemoglobin saturated with oxygen increases? - Correct answer-The concentration of hydrogen ions decreases. Identify the factors that favor the oxygenated form of hemoglobin. - Correct answer-High pH, low carbon dioxide Which metal ion is bound to the porphyrin ring in hemoglobin? - Correct answer-Iron Which feature of hemoglobin makes it an effective oxygen transport molecule? - Correct answer-Its affinity for oxygen is regulated by pH. Which enzyme binding scenario best describes enzyme specificity and action? - Correct answer-An enzyme binds one substrate or closely related substrates to catalyze only one reaction. How do the rates of enzyme-catalyzed reactions compare to those of corresponding uncatalyzed reactions? - Correct answer-They are 10 6 to 10 12 times faster. Which change will likely increase the activity of an enzyme currently at optimal conditions? - Correct answer-Significantly increasing substrate concentration What occurs immediately after the appropriate molecule enters the active site of an enzyme? - Correct answer-The enzyme binds the molecule to form an enzymemolecule complex. An inhibitor is added to the following hypothetical pathway, which results in an accumulation of compound C. Which enzyme is affected by the inhibitor? - Correct answer-enzyme 3 What is a temporary modification to protein structure by kinases that alters enzyme function? - Correct answer-Phosphorylation Acetylcholine is broken down to acetate and choline by an enzyme called acetylcholinesterase. Low levels of acetylcholine in the brain is associated with neurodegenerative disease. Which of the following medications could be used to treat neurodegeneration associated with low acetylcholine levels? - Correct answer-A noncompetitive inhibitor of acetylcholinesterase. Which type of inhibition occurs when a particular drug binds to the allosteric site of an enzyme and subsequently changes the enzyme's structure? - Correct answerNoncompetitive Proteases are a class of enzymes that hydrolyze protein strands into smaller units. A particular protease, located in the stomach, demonstrates activity at a pH = 1. What is the impact on the protease activity if the pH is increased to 7.4? - Correct answer-Significantly decrease What is an accurate description of the proton gradient that is formed during aerobic metabolism? - Correct answer-There is a higher H + concentration in the intermembrane space than in the matrix. Which complex polysaccharide acts as an energy-storing molecule in the liver? - Correct answer-glycogen How does insulin impact carbohydrate metabolism? - Correct answer-It stimulates the uptake of glucose from the blood by cells in the body. What occurs during the biochemical process of glycation? - Correct answer-A covalent bond forms between a sugar and a protein or lipid. Which metabolic pathway involves coenzyme A, NAD, and FAD? - Correct answer-beta oxidation Which cellular condition prompts the cell to perform fermentation rather than the citric acid cycle? - Correct answer-lack of O2 What causes the symptoms of noninsulin-dependent (Type 2) diabetes? - Correct answer-There are not enough GluT4 transporters on plasma membranes. Which molecule is pyruvate directly converted to under aerobic conditions? - Correct answer-Acetyl-CoA Which cellular organelle required for the citric acid cycle and electron transport chain is not present in red blood cells? - Correct answer-Mitochondria Which molecule is replenished by fermentation? - Correct answer-NAD+