BIOLOGY TEST QUESTONS TEST 2 1 You measure the amount of ATP and NADH consumed by the Calvin Cycle in 1 hour You find 30 000 molecules of ATP consumed but only 20 000 molecules of NADH Where did the extra ATP molecules come from a Cyclic electron flow b Photosystem I c Linear electron flow d Photosystem II e Chlorophyll 2 When oxygen is released as a result of photosynthesis it is a direct by product of a Chemiosmosis b The electron transfer system of photosystem I c The electron transfer system of photosystem II d Reducing NADP e Splitting water molecules 3 The dissociation of cytochrome c from the respiratory chain is necessary for electron flow from complex III to complex IV a True b False 4 The presences of cholesterol in the plasma membranes of some animals a Enables the animal to add hydrogen atoms to the unsaturated phospholipids b Enables the membrane to stay fluid more easily when cell temperature drops c Makes the animal more susceptible to circulatory disorders d Enables the animal to remove hydrogen atoms from saturated phospholipids e Makes the membrane less flexible allowing it to sustain greater pressure from within the cell 5 CAM plants are very sensitive to the presence of water and cannot grow in hot dry places a True b False 6 Succinate dehydrogenase catalyzes the conversion of succinate to fumarate The reaction is inhibited by malonic acid which resembles succinate but cannot be acted upon by succinate dehydrogenase Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid What is malonic acid s role with respect to succinate dehydrogenase a It blocks the binding of fumarate b It is an allosteric regulator c Its is a competitive inhibitor d It is able to bind to succinate e It is a noncompetitive inhibitor 7 jbgvThiamine pyrophosphate is a coenzyme for one of the three enzymes involved in the conversion of pyruvate to acetyl CoA If thiamine is deficient the coenzyme will be absent leading to the harmless disease Beri Beri a True b False 8 The sodium potassium ATPase pump controls NA and K concentrations in the cell This control is important as high or low concentrations of K are harmless but high or low concentrations of Na are dangerous a True b False 9 The cell membranes of Antarctic ice fish might have which of these adaptations a Very long chain fatty acids b No cholesterol c Branched isoperniod lipids d A higher percentage of trans fatty acids e A high percentage of polyunsaturated fatty acids 10 In mechanism photophosphorylation is most similar to a The Calvin Cycle b Carbon fixation c Substrate level phosphorylation in glycolysis d Reduction of NADP e Oxidative phosphorylation in cellular respiration 11 Suicide substrates refer to the binding of substrate analogues to the active site of an enzyme The reaction that follows yields a product that binds irreversibly at the active site and renders the enzyme inactive a True b False 12 Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH 8 solution What would be likely to happen a Cyclic photophosphorylation will occur b The isolated chloroplasts will generate oxygen gas c The isolated chloroplasts will reduce NADP to NADPH d The Calvin Cycle will be activated e The isolated chloroplasts will make ATP 13 In the presence of oxygen the three carbon compound pyruvate is catabolized in the citric acid cycle Before this pyruvate 1 loses a carbon given off as a molecule of CO2 2 is oxidized to form a two carbon compound called acetate and 3 is bonded to coenzyme A Why is coenzyme A a sulfur containing molecule derived from a B vitamin added a To provide a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle b To remove one molecule of CO2 c Because sulfur is needed for the molecule to enter the mitochondrion d Because it drives the reaction that regenerates NAD e In order to utilize this portion of a B vitamin which would otherwise be a waste product from another pathway 14 The highly explosive nature of the hydrogen oxygen reaction has made it impossible to come up with any practical applications for this reaction a True b False 15 During a laboratory experiment you discover that an enzyme catalyzed reaction has a DELTA G of 20kcal mol If you double the amount of enzyme in the reaction what will be the DELTA G for the new reaction a 40kcal mol b 20kcal mol c 40kcal mol d 0 kcal mol e 20 kcal mol 16 Metals such as iron in cytochromes of iron sulfur complexes function in cell respiration and photosynthesis as electron carriers a True b False 17 The use of fluoride in water and toothpaste has been a public health success in reducing tooth decay By increasing the amount of fluoride from 1 part per million to 70 parts per million per day human bones could be made stronger with no negative consequences a True b False 18 Which of the following statements describes enzyme cooperatively a A product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway b A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits c Several substrate molecules can be catalyzed by the same enzyme d A multienzyme complex contains all the enzymes of a metabolic pathway e A substrate binds to an active site and inhibits cooperation between enzymes in a pathway 19 Mitchell s chemiosmotic theory explains many aspects of oxidative phosphorylation except for the complex nature of ATP synthase a True b False 20 How is photosynthesis similar to C4 plants and CAM plants a In both cases rubisco is not used to fix carbon initially b Both types of plants make sugar without Calvin Cycle c Both types of plants make most of their sugar in the dark d In both cases only photosystem I is use e In both cases thylakoids are not involved in photosynthesis 21 At the end of the electron transport chain oxygen can be converted in a side reaction involving a oneelectron reduction to the superoxide anion At high amounts this could result in muscle destruction and Lou Gehrig disease a True b False 22 For each mole of glucose C6H12O6 oxidized by cellular respiration how many moles of CO2 are released in the citric acid cycle a 3 b 6 c 12 d 2 e 4 TEST 3 1 2 3 4 5 6 Which statement is TRUE of the centromere a It is the region of the cell where new spindle microtubules form at either end b It is the region of the