Which process is directly driven by light energy? 1) Creation of a pH gradient by pumping protons...
Question:
Which process is directly driven by light energy?
1) Creation of a pH gradient by pumping protons across the thylakoid membrane
2) Carbon fixation in the stroma
3) Reduction of NADP+ molecules
4) Removal of electrons from chlorophyll molecules
5) ATP synthesis
The Light-Dependent Reaction:
Photosynthesis is composed of two consecutive phases: light-dependent reactions followed by the light-independent reactions. The light-dependent reaction, as the name implies, relies on solar energy to initiate the reactions that lead to ATP synthesis and reduction of NADP+ into NADPH. These products of the light-dependent reaction are vital for the light-independent reaction. Since the light-dependent reaction makes use of the photosynthetic pigment chlorophyll, it takes place in the thylakoid space of the chloroplast whereas the light-independent reaction takes place in the stroma.
Answer and Explanation: 1
Become a Study.com member to unlock this answer! Create your account
View this answer
The correct answer is option 4.
Light energy is vital in photosynthesis. Without light, plants cannot possibly initiate the process that...
See full answer below.
Ask a question
Our experts can answer your tough homework and study questions.
Ask a question Ask a questionSearch Answers
Learn more about this topic:

from
Chapter 8 / Lesson 8Explore the light reaction of photosynthesis. Learn about the location, reactants, and products of light dependent reactions and photolysis in the lesson below.
Related to this Question
- Which process is directly driven by light energy? a. Creation of a pH gradient by pumping protons across the thylakoid membrane. b. Carbon fixation in the stroma. c. Reduction of NADP+ molecules. d. Removal of electrons from chlorophyll molecules. e. ATP
- Which process is directly driven by light energy? a) Creation of a pH gradient by pumping protons across the thylakoid membrane b) Carbon fixation in the stroma c) Reduction of NADP^+ molecules d) Removal of electrons from chlorophyll molecules e) ATP syn
- During the light reactions of photosynthesis, ATP is produced when hydrogen ions move a. down a concentration gradient from the thylakoid space to the stroma. b. against a concentration gradient from the thylakoid space to the stroma. c. down a concent
- During the light reactions: (a) What force is responsible for driving H+ into the thylakoid space? (b) What drives the H+ to leave the thylakoid space? (c) How is the creation of a concentration gradient related to the formation of ATP?
- Which pertains to the light-dependent reactions of photosynthesis? A) Occurs in the lumen of thylakoids of chloroplast B) Energy from electrons used to help create H+ concentration gradient C) Adenosine triposphate and Nicotinamide adenine dinucleotide ph
- Which of the following does NOT occur in the normal process of light-driven production of ATP and NADPH in plant chloroplasts? A) The oxygen-evolving enzyme generates protons in the thylakoid lumen. B) The cytochrome b_6-f complex pumps protons from the s
- A) What is the pH gradient across the thylakoid membrane (between the lumen and the stroma) used to do? B) The light reactions cause acidification of the lumen and alkalization of the stroma of the chloroplast. Why do these pH changes occur?
- Which photosynthesis process is most affected by ion leakage? a. Whether the cells can capture light b. Whether the Calvin cycle will function c. Whether ATP synthase will function d. Whether electrons will transfer from photosystem II
- Which of the following are produced when Hydrogen ions diffuse from the lumen of the Thylakoid to the Stoma? a) ATP b) NADPH c) Carbon Dioxide d) Glucose e) G3P.
- Which of the following does not occur in the light reactions of photosynthesis? a. Chlorophyll in the thylakoid absorbs solar energy. b. Water is split, providing electrons and giving off O2. c. ATP is generated. d. Carbon from the atmosphere is turned in
- Which of the following does Not occur in the light reaction of photosynthesis? a. Chlorophyll in the thylakoid absorbs solar energy. b. Water is split, providing electrons and giving off O2. c. ATP is generated. d. Carbon from the atmosphere is turned in
- In both photosynthesis and respiration, a hydrogen ion gradient is produced and then used to produce ATP through the action of transport/enzyme proteins. This overall process is called what?
- Light dependent reactions _______. a. capture the energy of sunlight with chlorophyll in PS I & PS II b. make ATP & NADPH using electron transport chains c. energize electrons in both PSI & PSII d. include both cyclic and noncyclic pathways e. all of
- Which process in photosynthesis produces oxygen? A. PS I B. PS II C. ATP Synthase D. Light Capture
- A complex of pigment molecules in the thylakoid membrane that is responsible for the light-capturing reactions. a.) autotrophs b.) Calvin Cycle c.) carotenoids d.) chlorophyll e.) heterotrophs f.) NADP+/NADPH g.) photons h.) photosystem i.) stomata j.) t
- Which process provides the energy needed to pump protons across the mitochondrial membrane during oxidative phosphorylation? a. the transfer of electrons in redox reactions b. the breakdown of ATP to ADP c. the rotation of the ATP synthase rotor d. oxidat
- Which process provides the energy needed to pump protons across the mitochondrial membrane during oxidative phosphorylation? (a) The transfer of electrons in redox reactions (b) The breakdown of ATP to ADP (c) The rotation of the ATP synthase rotor
- Which of the following is not produced in the light-dependent reactions of photosynthesis? A. NADPH B. sugars C. ATP D. oxygen
- Which of the following are products of the light reactions of photosynthesis? A. Glucose B. Water C. ATP D. NADP E. Light energy F. NADPH G. Carbon dioxide H. Oxygen
- Given that plants produce ATP and NADPH from photophosphorylation, for what purposes do they reduce CO2 to triose phosphate? a. At night, plants need the ATP produced by glycolysis and oxidative phosphorylation in the dark. b. Plants need triose phospha
- The immediate source of energy for ATP synthesis in chloroplasts and photosynthetic bacteria is: A. Electron transport B. The electrochemical proton gradient (PMF) C. Light D. Energized chlorophylls E. NADPH
- In the chloroplasts of green plants the photosynthetic electron transport chain does all of the following except: a. take place in the thylakoid b. establish a gradient by pumping protons into the thylakoid space c. produce O2 d. Use NADH as an electro
- The set of reactions that used NADPH and ATP formed in the light-capturing reactions to drive into the fixation of CO 2 a.) autotrophs b.) Calvin Cycle c.) carotenoids d.) chlorophyll e.) heterotrophs f.) NADP+/NADPH g.) photons h.) photosystem i
- Which process can be described as a four-step process for producing ATP from glucose? A) Osmosis B) Cellular respiration C) Chemical reaction D) Photosynthesis
- Which of the following processes creates the most ATP per glucose molecule metabolized? a. Glycolysis. b. Fermentation. c. Photorespiration. d. Aerobic cellular respiration. e. The light reactions of photosynthesis.
- Which of the following are reactants of the light reactions of photosynthesis? A. Glucose B. Water C. ATP D. NADP E. Light energy F. NADPH G. Carbon dioxide H. Oxygen
- Which molecule(s) regulate(s) photosynthesis by sensing the metabolic status of the chloroplast and regulating proton flow out of the thylakoid lumen? A: ATP synthase B: Antenna complex C: Chrolophyll B D: Carotenoids E: Chlorophyll A
- A proton gradient is established across the thylakoid membrane when protons diffuse from [{Blank}]. a. inner thylakoid space to stroma b. grana to thylakoid lumen c. thylakoid space to thylakoid lumen d. stroma to, thylakoid lumen e. cytoplasm to chl
- Which process in oxidative phosphorylation releases energy? a. the transfer of electrons in redox reactions b. the buildup of H+ ions on one side of the mitochondrial membrane c. the rotation of the ATP synthase rotor d. the synthesis of ATP from ADP and
- ATP is produced during the light reactions of photosynthesis. This ATP is used to in the Calvin Cycle. a. split water into oxygen gas and hydrogen b. produce NADP c. reduce carbon dioxide into glucose d. None of these are correct
- Which of the following statements about photosynthesis is NOT true? a. Without the input of light energy, photosynthesis is an endergonic process. b. The final step of the photosynthetic electron transport chain leads to the production of oxygen from wate
- Which of the following does not occur during the light-dependent reactions of photosynthesis? a. ATP synthesis b. Oxidation of water c. Carbon fixation d. Electron transport
- The light reactions of photosynthesis occur in: A. all membranes of the chloroplast. B. the stroma. C. the matrix. D. the tonoplast membrane. E. thylakoid membranes.
- Which of the following is(are) produced in the dark reactions of photosynthesis? (Select all that apply.) - Sugar - H2O - O2 - ADP - ATP - NADP+ - light energy - NADPH - CO2
- Choose the stage of the light reactions in which the following process occurs. Passes energized electrons down an electron transport chain to create ATP a. water-splitting photosystem b. NADPH-producing photosystem
- If the energy source for the light-dependent reaction of photosynthesis is sunlight, what energy is needed to fuel the carbon fixation reaction? a. ADP b. sunlight c. C o 2 d. ATP and NADPH e. ATP synthase
- The water-splitting step in photosynthesis: A) consumes H^+ and therefore contributes to the proton gradient across the thylakoid membrane. B) generates O_2 as well as H^+ in the thylakoid lumen. C) is catalyzed by an iron-sulfur cluster. D) occurs on the
- What unit of light energy is used by a photosystem, a group of pigment molecules and proteins located in the thylakoid membrane, for each light-dependent reaction? a. Neutron b. Proton c. Photon
- Energy for the Calvin cycle is supplied by from the light reactions. a. carbon dioxide and water b. ATP and NADPH c. carbon dioxide and ATP d. ATP and water e. electrons and hydrogen ions
- What is the role of NADP+ in photosynthesis? a) It forms NADPH to be used in the Calvin cycle. b) It forms part of photosystem II. c) It helps produce ATP from light reactions. d) It absorbs light energy. e) It is the primary electron acceptor.
- Which of the following are inputs to the carbon reactions? a. Glucose and ATP b. Carbon dioxide and NADP+ c. Oxygen and water d. ATP and NADPH
- During photosynthesis, photons raise electrons to higher energy levels. These excited electrons belong to what compound? a. water b. ATP c. chlorophyll d. electron transport chain
- The light reactions occur in the [{Blank}] with [{Blank}] as a reactant. a. thylakoid membrane; water b. stroma; oxygen c. chlorophyll; carbon dioxide d. chloroplasts; glucose
- In light-dependent reactions, what accumulates in the thylakoid compartment of chloroplasts? a. sugars b. hydrogen ions c. O2 d. CO2
- Which one of these occurs during the light reactions of photosynthesis? a. carbon dioxide fixation b. g3P production c. NADPH production d. reduction in carbon dioxide
- What is a reaction of photosynthesis that requires light called? Light energy is absorbed and converted to chemical energy in the form of ATP and NADPH.
- Protons in a chloroplast flow through an ATP synthase from the _______. a. Cytoplasm to the intermembrane space. b. Stroma to the intermembrane space. c. Thylakoid lumen to the stroma. d. Stroma to the thylakoid lumen. e. Intermembrane space to t
- The following processes use electron transfer chains and H^+ gradients to generate ATP. Where are the electron transfer chain enzymes located? How do the H^+ move? a. Photosynthesis b. Aerobic Respiration
- Which of the following are produced in the dark reactions? a. ATP, NADPH, oxygen, G3P b. ATP, NADPH, glucose, oxygen c. ADP, NADP+, G3P d. ADP, NADP+, G3P, oxygen e. ADP, NADP+, G3P, carbon dioxide
- During the light-dependent reactions of photosynthesis,: a. carbon dioxide is split into oxygen, carbon, electrons, and protons b. NADP+is reduced to NADPH c. enough ATP molecules are synthesized to power all other cellular functions d. electrons pass thr
- The light reactions of photosynthesis yield three products. They are: a. O_2, NADPH, and ATP. b. CO_2, NADP^+, and ATP. c. O_2, NADP^+, and ATP. d. H_2O, NADPH, and ATP.
- Describe the process of photosynthesis, including the structure and function of photosystem 1, photosystem 2, cyclic electron transport, ATP synthesis and the Calvin Cycle.
- Chemiosmosis of H^+ ions accumulate: a. inside the chloroplast. b. near the outer membrane. c. in the stroma. d. in the thylakoid space. e. on the thylakoid membrane.
- Which of these processes takes place in the cytoplasm of a cell? A. photosynthesis B. Krebs cycle C. glycolysis D. electron transport
- During light reactions of photosynthesis: A. the proton concentration of the thylakoid space increases. B. the proton concentration of the thylakoid space decreases. C. the stroma's proton concentration decreases. D. ATP is released into the thylakoid spa
- The pigment molecules responsible for photosynthesis are located in the: a. mitochondria b. cytoplasm of the cell c. stroma of the chloroplast d. thylakoid membrane of the chloroplast
- How are the light-dependent reactions of photosynthesis similar to the electron transport system in aerobic metabolism? a. They both involve the generation of a proton gradient that is harnessed to produce ATP. b. Reduced coenzymes donate their electrons
- Which of the following are products of the dark (light independent, Calvin cycle) reactions of photosynthesis? A. Glucose B. Water C. ATP D. NADP E. Light energy F. NADPH G. Carbon dioxide H. Oxygen
- What are the products of the light-dependent reactions? A. ATP, carbon dioxide gas, and NADPH. B, ATP, NADPH, and oxygen gas. C. Oxygen gas and glucose. D. Carbon dioxide gas, oxygen gas, and NADPH.
- Select the correct answer. How does the electron transport chain in photosystem I create potential energy to generate ATP? a. NADPH is reduced to NADP+ b. NADP+ is reduced to NADPH c. Carbon dioxide cleavage d. Pumping of protons e. Reduction of oxygen
- What is the driving force for ATP production in both cellular respiration and photosynthesis? Where exactly does ATP get produced during both of these processes?
- What term describes ATP production resulting from the capture of light energy by chlorophyll?
- Choose the stage of the light reactions in which the following process occurs. Produces ATP a. water-splitting photosystem b. NADPH-producing photosystem
- In photosynthesis, ATP is made by 1) chemiosmosis. 2) glycolysis. 3) the Krebs cycle. 4) the Calvin cycle. 5) the passing of electrons from photosystem.
- Photosynthesis is the process where energy is collected and what is released? A. Carbon Dioxide B. Glucose C. Oxygen D. Chloroplast
- Protons from electron transport will amass in the A. stroma B. intermembrane space C. matrix D. thylakoid lumen
- Plants make ATP during the light reactions of photosynthesis. Why do plants also need to carry out the process of cellular respiration? Explain what ATP produced from both processes are used for. Important Terms: Potential energy, Kinetic energy, End
- In the process of oxidative phosphorylation, ATP is generated from the potential energy created by: a. the breakdown of glucose b. the breakdown of pyrvuate c. photons from sunlight d. an electrochemical gradient
- What are the products of the light-dependent reactions? A. ATP, NADPH, and oxygen gas B. ATP, carbon dioxide gas, and NADPH C. carbon dioxide gas, oxygen gas, and NADPH D. oxygen gas and glucose
- In noncyclic photosynthesis, the excited electrons end up a. back on chlorophyll b. being used to make ATP c. being used to reduce NADP d. being transported "to the other side of the membrane" to set up a proton motive force. e. Being used to directly
- The pH gradient established by the electron transport chain: a. Exists between the matrix and the mitochondrial intermembrane space. b. Sets up a voltage gradient that drives GTP formation. c. Is established by electron transfer from FADH2 and NADPH from
- Which of the following are produced in the dark reactions? a. ATP, NADPH, Oxygen, G3P b. ATP, NADPH, Glucose, Oxygen c. ADP, NADP+, G3P d. ADP, NADP+, G3P, Carbon dioxide e. ADP, NADP+, G3P, Oxygen
- Summarize the processes that would lead to the accumulation of protons within the thylakoid lumen.
- Summarize the processes that lead to the accumulation of protons within the thylakoid lumen.
- What are the products of the light reactions that are subsequently used by the Calvin cycle? a. oxygen and carbon dioxide b. carbon dioxide and RuBP c. water and carbon d. electrons and photons e. ATP and NADPH
- In photosynthesis, what is the main purpose of the light reactions? a. To produce oxygen b. To produce sugars c. To produce NADPH and ATP d. To take in water e. To take in carbon dioxide
- In _________, electrons that have been energized by light contribute their energy to add phosphate to ADP, producing ATP. (a) crassulacean acid metabolism (b) the Calvin cycle (c) photorespiration (d) C4 pathways (e) photophosphorylation
- The light reactions act much like a battery to power the reactions of the Calvin cycle. This energy is stored as: a. ADP + Pi and NADP+ b. ATP and NADPH c. NADPH and NADP+ d. ADP + Pi e. ATP and NADP+
- PGAL molecules are formed from the reaction of PGA molecules with ATP and NADPH in this pathway. a. light-dependent reactions b. CAM pathway c. carbon dioxide fixation d. Calvin-Benson cycle e. C4 pathway
- Which of the following correctly explains steps involved in the mechanism by which cells use free energy? A. Glycolysis breaks down glucose into pyruvate, which is then oxidized in the citric acid cycle. B. Photosystem I captures photons of light, which a
- In chloroplasts, ATP synthase couples the synthesis of ATP to:\\ a. the diffusion of protons.\\ b. the reduction of NADP+.\\ c. the excitation of chlorophyll.\\ d. the reduction of chlorophyll.\\ e. the transfer of electrons.\\
- What are the products of non-cyclic photosynthesis (systems I and II) in plants and cyanobacteria? a. ATP b. NADP+ and ATP c. NADPH and ATP d. NADPH, O2, and ATP e. NADP+, O2, and ATP
- During photosynthesis, electrons from the reaction center chlorophyll are transferred to the electron transport system. These electrons are replaced by the splitting of ______ molecules. a. glucose b. carbon dioxide c. water d. ATP
- The light reaction of photosynthesis occurs in the: a. thylakoid membranes b. stroma c. cytoplasm d. matrix
- The light-harvesting reactions of photosynthesis: a. use H2O as the initial electron donor. b. occur in the stroma in the chloroplasts. c. utilize the ATP and NADPH produced by the CO2-fixation reactions. d. all of the above e. a and b, but not c
- What is NOT a byproduct of the light dependent reaction in photosynthesis? A) Adenosine triphosphate B) nicotinamide adenine dinucleotide (NAD) + hydrogen (H) C) FADPH D) \mathrm O_{2} E) More than one of the above(which ones)
- During photosynthesis, energy is used in creating ATP (through a protein gradient), and the component that carries this energy gets its energy from the sun. What is this component and where does it en
- During photosynthesis, electrons from the reaction center chlorophyll are transferred to the electron transport system. These electrons are replaced by the splitting of molecules. a. carbon dioxide b. ATP c. water d. glucose
- What are the mechanisms used to make ATP in cellular respiration and in photosynthesis?
- The electrons that are excited by light energy in photosystems II and I are eventually used to: a. breakdown RuBP b. convert glucose to carbon dioxide c. breakdown starch into glucose d. reduce NADP+ to NADPH
- Describe how ATP and NADPH are produced during the light-capturing reactions of photosynthesis.
- Photosynthesis is the process where energy is collected and ______ is released. (a) carbon dioxide (b) glucose (c) oxygen (d) chloroplast.
- The function of the light reactions of photosynthesis is to oxidize ___ and reduce ___. a) water, NADH \\b) water, NAD+ \\c) water, NADP+ \\d) oxygen, NADP+
- Choose the stage of the light reactions in which the following process occurs. Replaces energized electrons from electrons that have completed the 1st electron transport chain a. water-splitting photosystem b. NADPH-producing photosystem
- Select all statements that are correct concerning electron transport and ATP synthesis during photosynthesis in chloroplasts. a. Each photosystem (I and II) pump protons. b. Protons are pumped into the lumen of the thylakoid. c. The bulb of the synthase p
- Which of the following are produced directly as a result of the movement of electrons through the photosynthetic electron transport chain? a. Oxygen and carbohydrates b. Carbohydrates and ATP c. ATP and NADPH d. Water and carbohydrates.
- NADH is reoxidized by which of the following processes? A. Glycolysis. B. Fermentation. C. Krebs cycle. D. Electron transport chain. E. Light reactions to photosynthesis.
- What are the major events that occur during the light-dependent reactions of photosynthesis? a. light capture, reduction of oxygen, oxidation of NADPH, and formation of ATP b. light capture, oxidation of water, reduction of NADP+, and formation of ATP