UNE medical biochemistry Unit 1 Test Questions With Complete Solutions.

UNE medical biochemistry Unit 1 Test Questions With Complete Solutions. 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 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 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 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) lyases d) isomerases 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 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 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 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) OH- c) NADH d) pyridoxal phosphate 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 interactions between α-helixes and β-pleated sheets to form a domain Hemoglobin bound to heme is termed a holoprotein. The heme is required for oxygen binding and is defined as which of the following? a) apoprotein b) holoprotein c) heteroprotein d) prosthetic group prosthetic group Children with cystinosis have growth delay and renal issues to to accumulation of cysteine in cellular lysosomes. The defect involves a specific lysosomal membrane receptor that facilitates cysteine removal from the cell. An effective therapy involves administration of a drug with a similar structure to cysteine. This therapy reflects the general principle that competitive inhibitors typically resemble the structure of which of the following? a) substrates or ligands that bind the active site