Bio 101 Exam Questions with Correct Answers

Bio 101 Exam Questions with Correct Answers What equation best summarizes photosynthesis? - Answer-6 CO2 + 6 H2O → C6H12O6 + 6 O2 Where does the Calvin cycle occur? - Answer-in the stroma of a chloroplast The light reactions of photosynthesis use and produce . - Answer-water.... NADPH has a longer wavelength than . - Answer-red...green What enzyme phosphorylates ADP to make ATP? - Answer-ATP synthase releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment. - Answer-electron transport chain splits water into 1/2 O2, H+, and e- . - Answer-photosystem II Energized electrons from enter an electron transport chain and are then used to reduce NADP+. - Answer-photosystem I Chlorophyll can be found in . - Answer-photosystems I & II The light reactions of photosynthesis supply the Calvin cycle with - Answer-ATP and NADPH Which of the following sequences correctly represents the flow of electrons during photosynthesis? - Answer-H2O --- NADPH --- Calvin cycle True or false- Oxygen is produced during the Calvin cycle? - Answer-false Plants are photoautotrophs. What does this mean? - Answer-They are among the producers of the biosphere. They make their own food from inorganic materials. They are in the same category as algae and cyanobacteria. They use light energy to drive the synthesis of organic molecules The ultimate source of energy to support most life on Earth is . - Answer-sunlight The photosynthetic membranes are found in the in plant cells. - Answer- chloroplasts In the electromagnetic spectrum, the type of radiation that we call visible light occurs between . - Answer-ultraviolet radiation and infrared radiation What are the products of the light reactions of photosynthesis? - Answer-high-energy electrons, NADPH, ATP, oxygen When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by . - Answer-splitting water Photosynthesis is a redox reaction. This means that H2O is during the light reactions and CO2 is_ during the Calvin Cycle. - Answer-oxidized reduced The overall function of the Calvin cycle is . - Answer-making sugar C4 plants occur more commonly in desert conditions because . - Answer-they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed Define autotrophic - Answer-self-feeder, produce their organic molecules from CO2 and other inorganic raw materials obtained from their environment Define heterotrophic - Answer-obtain their organic material by feeding on compunds produced by other organisms What is the role of redox reactions in photosynthesis? - Answer-H2O is split, electrons are transferred along with hydrogen ions from H2o to CO2, reducing it to sugar. Electrons increase in potential energy as they move from H2o to C6H12O6, this process requires energy (endergonic). Energy boosts are provided by light What takes place during the light reactions in photosynthesis? - Answer-takes place in thylakoid membranes, use solar energy to produce ATP and NADPH, supplies chemical energy and reducing power (solar energy to chemical energy) What takes place during the Calvin Cycle in photosynthesis? - Answer-incorporates CO2 into organic molecules prucing sugar (chemical energy to sugar) What wavelengths are most effective for photosynthesis? - Answer-violet-blue/ red light are most effective in driving photosythesis Explain what happens when a solution of chlorophyll a absorbs photons. Explain what happens when chlorophyll a in an intact chloroplast absorbs photons. - Answer- chlorophyll a- (CH3) absorbs at slightly different wavelengths, blue-green color chlorophyll b- (CHO) olive-green color due to structural differences List the components of a photosystem and explain the function of each component. - Answer-reaction center complex- includes special pair of chlorophyll a molecules photon- strikes a pigment molecule in light-harvesting complex energy- passed from molecule to molecule until it reaches reaction center complex Excited electron (e-)- form "special e-"- transferred to primary e- receptor path