WGU Biochemistry PA Questions and Answers 100% Passed

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WGU Biochemistry PA Questions and Answers 100% Passed A commonly used technique for protein denaturation is adding an acid or a base to dramatically change the pH. Which force is most impacted by thi... s change in pH? Correct Answer- Ionic bonds 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 non-competitive inhibitor of acetylcholinesterase. 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 Answer- Protein aggregation 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 Answer- Protein aggregation Approximately how many ATP molecules can be produced from a single molecule of glucose during aerobic metabolism? Correct Answer- 30 Assuming 100% reaction efficiency, how many DNA copies are created after the completion of four complete PCR cycles? Correct Answer- 16 Assuming 100% reaction efficiency, how many DNA copies are created after the completion of four complete PCR cycles? Correct Answer- 16 At low O 2 concentrations, how does myoglobin's affinity for O 2 relate to hemoglobin's affinity for O 2? Correct Answer- Myoglobin has a much greater affinity for O 2 than hemoglobin does. Frying an egg changes the egg white from a clear liquid to an opaque solid. Which molecular change in the albumin protein causes this change in appearance? Correct Answer- Hydrophobic interactions form between denatured egg white proteins. 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. How does heating beyond optimum temperature inactivate enzymes? Correct Answer- By breaking the covalent bonds in the primary structure How does hemoglobin keep blood pH neutral during exercise? Correct Answer- Deoxygenated hemoglobin binds to excess H +. How does insulin impact carbohydrate metabolism? Correct Answer- It stimulates the uptake of glucose from the blood by cells in the body. How does insulin reduce blood glucose levels? Correct Answer- It increases the translocation of GluT4 transporters to the cell membrane. How does pH level promote the deoxygenated conformation of hemoglobin? Correct Answer- When pH lowers, excess H + binds to negatively charged side chains on hemoglobin and changes ionic bonds between subunits to favor the T-state How does the Bohr effect describe the relationship between carbon dioxide levels, blood pH and the amount of oxygen bound to hemoglobin? Correct Answer- An increase in carbon dioxide production leads to a decrease in blood pH, causing hemoglobin to release oxygen more readily. How is energy provided for ATP production during the final stage of aerobic metabolism? Correct Answer- Protons diffuse through a transmembrane protein. How many ATP molecules are used in the conversion of pyruvate to glucose? Correct Answer- 6 How would lipid production in a cell change in order to maintain fluidity of its cell membrane as it adapts to lower temperatures? Correct Answer- Produce lipids with shorter fatty acid chains. Identify the factors that favor the oxygenated form of hemoglobin. Correct Answer- High pH, low carbon dioxide 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 Long-distance runners often consume energy gels that are high in carbohydrates during their run. Which pathway is triggered by the intake of carbohydrates during exercise? Correct Answer- glycolysis Long-distance runners often consume energy gels that are high in carbohydrates during their run. Which pathway is triggered by the intake of carbohydrates during exercise? Correct Answer- Glycolysis Mice with low levels of agouti gene expression tend to have yellow fur and are obese, while mice with higher levels of expression are brown and of normal weight. Studies show that expression of the agouti gene in mice can be controlled by epigenetics. What scenario describes epigenetic regulation of the agouti gene? Correct Answer- Mother mice fed methyl-rich diets during pregnancy give birth to offspring with decreased agouti gene expression compared to those fed a methyl-poor diet. ow many molecules of lactate are required to produce one molecule of glucose? Correct Answer- 2 Oxidative damage to DNA can often result in the alteration of a single nucleotide. Which DNA repair mechanism would repair this type of damage? Correct Answer- The mutation rate of all other genes is higher due to failure to repair. 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 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 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 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 are possible blood types of the parents of a patient with blood type AB? Correct Answer- A and B What causes the symptoms of noninsulin-dependent (Type 2) diabetes? Correct Answer- There are not enough GluT4 transporters on plasma membranes. What is a function of cholesterol? Correct Answer- maintains membrane fluidity What is a glycolipid? Correct Answer- A polymer of monosaccharides covalently attached to a membrane lipid. What [Show More]

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