Use this information for questions 12-13. Refer only to the 15. In the preience of the hydrophobic proton carrier DCCP. tabulated information in answering these questions. which is true for the electron transport chain? Tha fathruvine arotocol is eiven in a lab manual: (A) Mitochondria na longer reduce O2 to H2O. (B) Electrons no longer enter the electron transport chain. (C) Activity of Comples V (ATP Synthase) is greatly. decreased. (D) The P/O tatio for FADH2 becomes larger than the PO ratio for NADH. After incubation, add substraie dissolved in the buffer, and (E) Protons are no longer pumped from the recond the absorbance at 520 nm every 30 seconds. mitochondrial matrix to the intermembrane space. The reaction of enzyme plus sabstrate gives a pink complex. 16. In the inner mitochondrial membrane, electrons are 12. Which determination can be made from this evperiment? acquired from reduced coenzymes and (A) The effect of changing the amount of subctrate on and transported through several membrane complexes to the rate of reaction. resulting in the production of (B) The effect of time on the rate of the enzyme (A) NADH2,FADH2,O2,H2O catalyzed reaction. (B) NADH2FMNH2,O2,H2O (C) The eflect of changing the amount of buffer on the (C) NADH,FADH2,ADP,ATP rale of reaction. (D) NADPH,FADH2, ADP, ATP (D) How much enryme is necessary for the reaction to (E) NADPH. FMNH, ADP.ATP (E) If CaCl2 is necessary for the reaction. 17. What is the inital source of electrons in photosynthefic clectron transport? 13. Why is the amount of buffer used not constant? (A) NADH (B) NADPH (A) No special reason, (C) glucose (D) ATP: (B) To keep the total volume constant. (E) H2O (C) Because the amount of product changes. 18. The 14:0 fatty acid shown, in which the indicated carben (D) It is the effect of the buffer we are testing. was labeled with C14, is fed to an animal: (E) To kecp the absorbance of the solution constant. 14. Phosphory lation of enxymes is a common mechanism used by signal transduction pathways to regulate the activity of encymes. Which best describes the way in After allowing 30 minutes for -oxidatica to take phace. which phosphorylatios affects enzyme activity? the label would be in (A) Phosphorylation blocks the active site of the enzyme (A) acetyl-CoA. and inhibits function. (B) glucose. (B) Phosphorylation causes conformational changes that (C) propanoyl-CoA. can alter enxyme function. (D) all of the above: (C) Phosphoorylation affects the half-life of proteins (E) none of the above. which results in aliered activity. (D) Phosphorylation introduces the phosphate functional 19. All of these are required for fatty acid synthesis except group necessary for enxyme activity. (A) acety]. CoA. (B) acyl carrice prosein, (E) Phosphorylation affects the binding of allosicric (C) ATP (D) waloayl.CoA. effectors to enzymes resulting in altered activity. (E) NADH