UNE Medical Biochemistry Midterm Exam Questions With Correct Answers

UNE Medical Biochemistry Midterm Exam Questions With Correct Answers Which of the following proteins is likely to have quaternary structure? - answerA multimeric protein that contains multiple peptide chains Prosthetic groups are complex nonprotein molecules that participate in catalysis by providing functional groups that form a covalent intermediate between the enzyme and the substrate. Which of the following is an example of a coenzyme or cofactor that participates in a covalent catalysis reaction? - answerPyridoxal phosphate Which of the following best describes a protein domain? - answerA section of a protein structure sufficient to perform a particular chemical or physical task Cleavage of fructose 1,6 bisphosphate to dihydroxyacetone and Glyceraldehyde 3-phosphate involves the breaking of a carbon-carbon bond through a process other than oxidation or hydrolysis. This is achieved by what class of enzymes? - answerLyase A 55-year old man is brought to the emergency room with a chief complaint of chest pain and tingling in his left arm. Elevation of which of the following enzymes in circulation would be most indicative of myocardial infarction? - answerTroponin Allosteric activators of hemoglobin will increase substrate binding through which of the following mechanisms? - answerBinding the protein, and keeping it in the "R" conformation Which of the following best describes tertiary structure? - answerInteractions between alpha helices and beta sheets to form a domain How do most enzymes reduce the activation energy needed to move a reaction forward? - answerproviding an active site most complementary to the transition state Domains are common structural elements that retain a particular function within the protein. Which of the following is an example of a protein domain? - answerAn arrangement of beta-strands connected by alpha-helices (beta-alpha-beta-alpha) Which amino acid would not be commonly found in the middle of an alpha-helical domain? - answerProline Which of the following is a true statement with regards to the malate-aspartate shuttle system? - answerGenerates 2.5 molecules of ATP in mitochondria per each NADH from glycolysis. Complex II (Succinate Q-reductase) is not considered part of the process of oxidative phosphorylation because it is unable to do which of the following activities? - answerPump protons from the mitochondrial matrix into the inter membrane space. Succinate is a substrate for which complex in the electron transport chain? - answerComplex II (Succinate-Q reductase) The glycerophosphate shuttle is the major shuttle of most tissues. Which of the following best describes the transfer of electrons by this shuttle? - answerElectrons are directly transferred from glycerol 3-phosphate to an FAD containing glycerol phosphate dehydrogenase. A 19-year old male is being evaluated for muscle weakness. Evaluation of a muscle biopsy revealed normal rates of succinate oxidation but very low rates of pyruvate oxidation. Further testing determined normal levels of enzymatic activity in both malate dehydrogenase and pyruvate dehydrogenase. Based on this data, the patient may have a mutation in a gene encoding for which mitochondrial protein? - answerComplex I (NADH Q-oxidoreductase) Which of the following components of the electron transport chain passes electrons to O2 causing it to be reduced to H2O? - answerCytochrome c oxidase As electrons flow through complexes in the inner mitochondrial membrane, protons are pumped from the matrix into the inter membrane space. Which of the following statements is most reflective of the pH in the inter membrane space? - answerThe pH is higher in the matrix when compared to the intermembrane space. The malate-aspartate shuttle is used to move reducing equivalents o cytosolic NADH into the mitochondria where it can be oxidized. Which of the following compounds is used to move the reducing equivalents from cytosolic NADH into the mitochondria? - answerMalate ATP is a high energy molecule that is often hydrolyzed during reactions. The energy within ATP is stored primarily in which of the following components of the molecule? - answerIn the high energy phosphate bonds Which of the following is an example of enzyme regulation through covalent modification? - answerphosphorylation of muscle glycogen phosphorylase Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen phosphorylase at site unique to the active site. This enhances the activity of these enzymes. This is an example of which of the following types of enzyme regulation? - answerAllosteric activation A 28 year old male is recently diagnosed with HIV. As part of his treatment he is prescribed Nevirapine which interferes with retroviral reverse transcript erase enzyme. Use the graph