Bio D103 Final Set with Complete Solutions 2024

Which of the following is NOT a common mechanism used to regulate activity of signaling proteins ? A. Binding of another molecule to the signaling protein. B. Degradation of the signaling molecule by proteolysis. C. Uptake of the signaling protein by the ER. D. Masking of a NLS signal in the signaling protein by another protein. E. Covalent modification of a protein involved in a signaling pathway (e.g. phosphorylation) C. Uptake of the signaling protein by the ER You are working in a lab as a Bio199 student studying the function of a novel gene that encodes a cell surface transmembrane receptor in Drosophila (fruit-fly). Drosophila mutants that lose the function of this receptor show dramatic developmental defects involving loss of legs. Your boss asks you to start analyzing the mouse version of the gene encoding the related cell surface receptor. What might you discover when you undertake this task ? A. The mouse genome has several genes whose exon coding sequence differ slightly from each other, but each gene is predicted to encode a receptor that is similar to the receptor found in Drosophila. B. The mouse genome appears to also have only one gene encoding the transmembrane receptor and its amino acid sequence is identical. C. The mouse genome doesn't appear to have a gene that can encode a protein related to the receptor found in Drosophila. A. The mouse genome has several genes whose exon coding sequence differ slightly from each other, but each gene is predicted to encode a receptor that is similar to the receptor found in Drosophila. Why would nitric oxide be a poor endocrine signaling molecule? A. Because it is only synthesized by a few cell types. B. Because it would be taken up by all cell types due to the fact that it does not need a cellsurface receptor. C. Because it has a very short lifetime. D. Because it would only be synthesized in cells containing arginine. C. Because it has a very short lifetime Which of the following describes a correct order of events that occurs during signaling between to induce vasodilation? A. Endothelial cell secretes acetylcholine - G-protein coupled receptor in smooth muscle cellbinds to guanylyl cyclase - [increased cGMP] induces protein kinase G activity that leadsto smooth muscle relaxation B. Acetylcholine bind to G-protein coupled receptor on surface of smooth muscle cell -smooth muscle cell synthesizes nitric oxide (NO) - NO diffuses into endothelial cell -activates guanylyl cyclase - [increased cGMP] leads to smooth muscle relaxation. C. Activation of Ca 2+- calmodulin in endothelial cell - smooth muscle cell synthesizes nitricoxide (NO) - NO activates guanylyl cyclase - [increased cGMP] leads to smooth musclerelaxation. D. Activation of nitric oxide synthase in endothelial cell - NO activates guanylyl cyclase insmooth muscle cell - [increased cGMP] leads to smooth muscle relaxatio D. Activation of nitric oxide synthase in endothelial cell - NO activates guanylyl cyclase insmooth muscle cell - [increased cGMP] leads to smooth muscle relaxation Which of the following changes in enzyme activity could produce the strongest effect on vasodilation? A. Increase guanylyl cyclase and decrease cGMP phosphodiesterase. B. Increase both guanylyl cyclase and cGMP phosphodiesterase. C. Decrease guanylyl cyclase and increase cGMP phosphodiesterase. D. Decrease both guanylyl cyclase and cGMP phosphodiestera A. Increase guanylyl cyclase and decrease cGMP phosphodiesterase. Which of the following is not true regarding protein domains? A. They often confer a binding specificity. B.They are a contiguous region of a protein. C.They contain some amino acids that vary among proteins. D. They always bind receptors. E. They have some conserved amino acids. D. They always bind receptors. What is the receptor for nitric oxide (NO) in blood vessels? A.Calmodulin in endothelial cells. B.Guanylyl cyclase in endothelial cells. C.Cyclic GMP in smooth muscle cells. D.Nitric oxide synthase in endothelial cells. E.Guanylyl cyclase in smooth muscle cells E.Guanylyl cyclase in smooth muscle cells Indicate true (T) or false (F) for the statements below regarding cellular signaling mediated by nitric oxide (NO). Your final answer will be a four-letter string composed of letters T and F only, e.g. TTTF. ( ) Once produced, NO can diffuse to neighboring cells. ( ) The lifetime of NO is 5 - 10 minutes. ( ) NO normally decreases cGMP concentration by directly activating cGMP phosphodiesterase. ( ) The drug Viagra® counteracts the effects of NO on penile blood vessels. TFFF