Question

inhibitor? 9 How are the kinetics of an enzyme-catalyzed reaction affected by a competitive A) Veax decreased, Ke increased B) Veax decreased, A decreased C) Vax decreased K unchanged D) V unchanged, Kw increased E V unchanged, Ki decreased 20. The ability for an enzyme to pick out one particular substrate from the myriad of molecules floating around its environment is an example of A) natural selection B) specificity C) high affinity D) processivity E) none of the above The most notable difference between-_ and other lipids is the presence of four fused rings A) cholestero 21· B) arachidonic acid C) gangliosides D) plasmologens E) triacylglycerols 22. Desensitization of a G protcin-coupled receptor is caused by phosphory lation of the receptor by a specific kinase. What protein recognizes the phosphorylated receptor? A) phospholipase C B) the G protein y subunit C) CAMP phosphodiesterase D) adenosine receptor E) arrestin 23. The major lipid component of cell membranes are A) triacylglycerols B) cholesterol D) Page 5

Answer 1

19. D. Competitive inhibitors can be overcome by adding more substrate to the reaction, therefore increasing the chance of substrate and enzyme reaction which results in altering km leaving vmax same.

20. B. Specificity means tha ability of an enzyme to pick out an enzyme from a myriad of enzymes in sorrounding environment.

21. A. Steroids such a cholestrol has four fused rings whicj is the major difference between steroid and lipid.

23. B. The three main components are glycolipids phospholipids and cholestrol.