Which of the following statements are true? a) Phospholipase C catalyzes the conversion of PIP3 to IP3 and DAG b) PI3K catalyzes the conversion of PIP2 to PIP3 c) Both a and b d) Neither a or b

Which of the following are the common features for both adenylate cyclase and guanylyl cyclase? a) Both enzymes are integral membrane proteins b) The products produced by both enzymes acts as a second messenger c) Both a and b d) Neither a or b

The p75 receptor differs from Trk receptors in that it a) can promote cell death. b) has high affinity for all neurotrophins. c) only binds a particular type of neurotrophin. d) can bind NGF to promote cell survival.

Which of the following is not a true statement? A.) steroid and thyroid hormone signaling would be impaired if the plasma level of carrier proteins is not optimal. B.) Steroid and thyroid hormone-receptor complexes form dimers when they bind to the hormone-response elements on DNA C.) Epinephrine uses the adenylate cyclase and the phospholipase C second messenger systems D.) signaling by a peptide hormone would be impaired if a second messenger system is not functional in the target cell E.) signaling by a steroid hormone would be hindered if the adenylated cyclase second messenger system is not functional in the target cell.

Di-isopropyl fluorophosphate is a(n) .................. inhibitor of chymotrypsin ? a) allosteric b) irreversible c) uncompetitive  d) competitive e) mixed

Which of the following does not  involve a dimerization event? Explain why you chose, or did not choose, each answer. a) Transport of R-SMAD from the cytoplasm to the nucleus. b) Ligand binding to the EGF receptor c) CREB binding to the cAMP response element (CRE) d) Ligand binding to the TGF βreceptor

Q18

Which of these is not a component of phosphatidylcholine?  a)  glycerol   b)  phosphate  c)  choline   d)  sphingosine

draw A molecular model for cohesin

Which of the following peptides is most likely to serve as a signal sequence in human tissues a.) NLYIAPYKHAPKLAALGKVP b.)NLYIAPYKHATIENHDPLRKRK c.)MATGSRTSLLAFALLCLPWLQEGSAF d.)YDILETYEAGIVLKGSEVKSLREKGT e.)SLREKGTVSFKDSFVRIENGEAW