BIOL 1P91 Prep Test Questions And Answers Verified 100% Correct

BIOL 1P91 Prep Test Questions And Answers Verified 100% Correct 3 chemical products produced in photosynthesis - ANSWER O2 NADPH ATP noncyclic electron flow - ANSWER When electrons at PSII are transferred to NADPH in a linear flow Produces both ATP and NADPH in equal amounts cyclic electron flow - ANSWER Uses only PSI and produces ATP, but not NADPH Releases energy to transport H+ Useful when there's excess NADPH Z scheme of photosynthesis - ANSWER Zigzag shape of energy curve Electron energy increases and decreases as it moves from PSII through PSI to NADPH Electron on a nonexcited pigment molecule in PSII starts with the lowest energy Light excites the electron in PSII, and PSI boosts the electron to an even higher level synthesis of carbohydrates via the Calvin cycle - ANSWER CO2 is incorporated into carbohydrates Requires a massive input of energy (For every 6 CO2 incorporated, 18 ATP and 12 NADPH are required) Product is glyceraldehyde-3-phosphate (G3P) Glucose is made from G3P in a later process (NOT in the Calvin cycle) 3 phases of the Calvin Cycle - ANSWER carbon fixation, reduction and carbohydrate production, regeneration of RuBP 3 environmental conditions that can influence the efficiency and the way the Calvin cycle works - ANSWER Light intensity Temperature Water availability What can Rubisco (RuBP) function as in photorespiration - ANSWER Mainly a carboxylase, but can also be an oxygenase Photorespiration - ANSWER Occurs mainly in C3 plants When O2 binds to RuBP and releases CO2 More likely to occur in hot and dry environments Is favored when CO2 is low and O2 is high C4 plants - ANSWER Minimize photorespiration Makes oxaloacetate Has the Hatch-Slack Pathway, in which leaves have Mesophyll cells and Bundle-sheath cells Mesophyll cells - ANSWER CO2 enters via stomata and a 4 carbon compound is formed Bundle-sheath cells - ANSWER 4 carbon molecule is transferred, which releases a steady supply of CO2, which minimizes photorespiration Which is better, C3 or C4 plants - ANSWER depends on environment in warm, dry climates C4 plants conserve water and prevent photorespiration in cooler climates, C3 plants use less energy to fix CO2 90% of plants are C3 CAM plants - ANSWER Separate processes by time Carbon fixation occurs at night, Calvin cycle during the day Stomata is closed during the day and opens at night to conserve water What is cellular respiration? process by which living cells obtain energy from organic molecules and release waste products aerobic respiration uses _____ Oxygen what is consumed during aerobic respiration? O2 what is released during aerobic respiration? CO2 what happens when glucose is broken down via oxidation? a tremendous amount of free energy is released (-685Kcal/mol) when glucose is broken down some of the energy is lost as heat but much of it is used as energy. What are the 3 energy intermediates? 1. ATP 2. NADH 3. FADH2 Name 4 metabolic pathways 1. glycolysis 2. breakdown of pyruvate 3. citric acid cycle 4. oxidative phosphorylation during glycolysis what is broken down? 2 pyruvate molecules what do the 2 pyruvate from glycolysis break down into? 2 ATP and 2 NADH molecules Where does glycolysis occur? cytosol in eukaryotes When does substrate level phosphorylation occur? when an enzyme transfers phosphate from a phosphorylated organic molecule to ADP what metabolic pathways occur in the mitochondria matrix?? breakdown of pyruvate and citric acid cycle what is each pyruvate broken down to during the breakdown of pyruvate?