UNE medical biochemistry Unit 1 Test All Possible Questions and Answers with complete solution

Changes in the physiological variables listed below can alter the affinity of hemoglobin for oxygen. Which of the following will lower the affinity of hemoglobin for oxygen? a) decrease in protons b) increase in 2,3 bisphosphoglycerate (BPG) c) increase in pH d) decrease in CO2 - Answer Increase in 2,3 bisphosphoglycerate (BPG) Domains are common structural elements that retain a particular function within the protein. Which of the following is an example of a protein domain? a) a prosthetic group such as heme b) irregular coils and loops c) an arrangement of β-strands connected by α- helixes d) a single α- helix - Answer An arrangement of β-strands connected by α-helixes A 22-year-old female is diagnosed with acute pancreatitis. Elevation of which of the following serum enzymes would be consistent with this diagnosis? a) lactate dehydrogenase b) amylase c) troponin d) creatine kinase - Answer amylase Movement of ammonia from an amino acid to an alpha-keto acid involves a family of enzymes best categorized as: a) transferases b) ligases c) lyasesd) isomerases - Answer transferases Which of the following proteins is likely to have quaternary structure? a) a protein that contains both α-helix and β-sheet secondary structures b) a multimeric protein that contains multiple peptide chains c) a small protein consisting of a single amino acid chain d) a large transmemberane protein with seven alpha helical domains - Answer a multimeric protein that contains multiple peptide chains Cleavage of fructose 1, 6 bisphosphate to dihydroxyacetone and glyceraldehyde 3-phosphate is achieved by what class of enzymes? a) ligase b) lyase c) transferase d) hydrolase - Answer Lyase Which of the following best describes the structure of heme? a) a planar porphyrin ring that binds iron b) a nicotinamide structure that is readily oxidized c) an n-linked glycosylation d) a negatively charged phosphate group - Answer a planar porphyrin ring that binds iron 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? a) ATP b) OHc) NADHd) pyridoxal phosphate - Answer pyridoxal phsophate Which of the following best describes tertiary structure? a) interactions between differing subunits of a protein b) interactions between α-helixes and β-pleated sheets to form a domain c) interactions between amino acids 4 residues away from each other d) interactions between single amino acids adjacent to one another - Answer interactions between α-helixes and β-pleated sheets to form a domain