Photosynthesis and Cellular Respiration Quiz
86 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary role of photosystems I and II in photosynthesis?

  • Transport electrons to the terminal electron acceptor
  • Synthesize ATP directly from ADP
  • Capture inorganic phosphate
  • Absorb free energy from light and boost electrons (correct)

    • What establishes the electrochemical gradient across the thylakoid membrane during the light-dependent reactions?

  • Absorption of carbon dioxide
  • Transfer of ATP to ADP
  • Transfer of electrons through the electron transport chain (correct)
  • Movement of protons through ATP synthase

    • Which molecule serves as the terminal electron acceptor in photosynthesis?

  • NADP+ (correct)
  • NADH
  • Oxygen
  • FADH2

    • During the Calvin cycle, what is primarily synthesized from carbon dioxide?

    <p>Organic molecules</p> Signup and view all the answers

    In cellular respiration, which electron carriers deliver electrons to the electron transport chain?

    <p>NADH and FADH2</p> Signup and view all the answers

    What compound is produced in the light-dependent reactions of photosynthesis?

    <p>ATP and NADPH</p> Signup and view all the answers

    Which part of the chloroplast is involved in the Calvin cycle?

    <p>Stroma</p> Signup and view all the answers

    What is the function of ATP synthase in photosynthesis?

    <p>Synthesize ATP from ADP and inorganic phosphate</p> Signup and view all the answers

    Which of the following structures is responsible for the absorption of light energy in plants?

    <p>Chloroplasts</p> Signup and view all the answers

    What is the primary role of stomata in plant leaves?

    <p>To facilitate gas exchange</p> Signup and view all the answers

    Which process describes the conversion of carbon dioxide and water into glucose and oxygen using light energy?

    <p>Photosynthesis</p> Signup and view all the answers

    During the oxidation process in cellular respiration, what is produced from glucose and oxygen?

    <p>Carbon dioxide and water</p> Signup and view all the answers

    What is the purpose of chlorophyll in the process of photosynthesis?

    <p>To absorb sunlight for converting carbon dioxide and water into glucose</p> Signup and view all the answers

    Which of the following nutrients is NOT typically absorbed through the roots of plants?

    <p>Oxygen</p> Signup and view all the answers

    What is the end product of photosynthesis?

    <p>Glucose and oxygen</p> Signup and view all the answers

    The endosymbiotic theory explains the evolution of which cellular structure involved in photosynthesis?

    <p>Chloroplasts</p> Signup and view all the answers

    What is the net product of one complete cycle of carbon fixation?

    <p>One G3P molecule</p> Signup and view all the answers

    How many ATP molecules are consumed during three turns of the carbon fixation cycle?

    <p>9 ATP molecules</p> Signup and view all the answers

    Which enzyme catalyzes the initial reaction in the carbon fixation process?

    <p>RuBisCo</p> Signup and view all the answers

    What are the products formed after the reduction phase of the carbon fixation cycle?

    <p>Glyceraldehyde-3-P (G3P)</p> Signup and view all the answers

    What is regenerated at the end of the carbon fixation cycle to continue the process?

    <p>RuBP and ATP</p> Signup and view all the answers

    Which of the following best describes the role of light energy in the process of electron flow?

    <p>It drives the synthesis of ATP and NADPH.</p> Signup and view all the answers

    What happens to P680 after it absorbs a photon of light?

    <p>It loses an electron to the primary electron acceptor.</p> Signup and view all the answers

    What is produced when water is split during photosynthesis?

    <p>Electrons, protons, and an oxygen atom are produced.</p> Signup and view all the answers

    Why is P680+ considered the strongest oxidizing agent known?

    <p>It can readily oxidize other molecules by removing electrons.</p> Signup and view all the answers

    What is the result of the transfer of electrons from the primary electron acceptor in Photosystem II?

    <p>It initiates a new flow of electrons from Photosystem I.</p> Signup and view all the answers

    Which of the following statements about electron transfer in photosynthesis is false?

    <p>Light absorption by pigments occurs after the electrons are transferred.</p> Signup and view all the answers

    How does the flow of electrons contribute to the overall process of photosynthesis?

    <p>It generates proton gradients used for ATP synthesis.</p> Signup and view all the answers

    In the linear electron flow, what happens after P680 transfers its electron?

    <p>P680 must replace the lost electron by splitting water.</p> Signup and view all the answers

    Which option is NOT a function of Photosystem II?

    <p>Release of carbon dioxide</p> Signup and view all the answers

    What is primarily produced during cyclic photophosphorylation?

    <p>ATP only</p> Signup and view all the answers

    What adaptation allows CAM plants to conserve water during daytime?

    <p>They absorb CO2 during the night</p> Signup and view all the answers

    What is the effect of photorespiration on the Calvin cycle?

    <p>It leads to a loss of carbon to production of CO2.</p> Signup and view all the answers

    Which observation best supports the idea that Elysia chlorotica can perform photosynthesis?

    <p>It grows in the absence of food sources when exposed to light.</p> Signup and view all the answers

    Which molecule is NOT produced in the light reactions of photosynthesis?

    <p>G3P</p> Signup and view all the answers

    Which process allows C4 plants to minimize photorespiration?

    <p>By using different cells for carbon fixation and the Calvin cycle.</p> Signup and view all the answers

    What role does NADP+ play in photosynthesis?

    <p>It accepts electrons in the light-dependent reactions.</p> Signup and view all the answers

    Which enzyme is primarily involved in the carbon fixation process of C4 plants?

    <p>PEP carboxylase</p> Signup and view all the answers

    Which substance is synthesized in the Calvin cycle from carbon dioxide?

    <p>G3P</p> Signup and view all the answers

    How do CAM plants optimize their carbon fixation?

    <p>By partitioning photosynthesis between day and night.</p> Signup and view all the answers

    What is a significant impact of the increase of O2 levels in the atmosphere on Rubisco?

    <p>Rubisco has become less efficient, accepting both CO2 and O2.</p> Signup and view all the answers

    What is the primary output of the light-dependent reactions?

    <p>ATP and NADPH</p> Signup and view all the answers

    What is the main reason for plants to evolve alternative carbon fixation systems?

    <p>To enhance the efficiency of carbon fixation.</p> Signup and view all the answers

    During hot, dry days, how do C3 plants respond to conserve water?

    <p>By partially closing stomata to reduce CO2 intake.</p> Signup and view all the answers

    What can potentially improve a plant's efficiency in carbon fixation if photorespiration is reduced?

    <p>50% more effectiveness in photosynthesis.</p> Signup and view all the answers

    What is the net product of three turns of the carbon fixation cycle?

    <p>One G3P molecule</p> Signup and view all the answers

    How many ATP and NADPH molecules are consumed in the synthesis of sugar from carbon fixation?

    <p>9 ATP and 6 NADPH</p> Signup and view all the answers

    Which molecule is directly involved in the regeneration of RuBP during the Calvin cycle?

    <p>G3P</p> Signup and view all the answers

    What is the role of RuBisCo in the processes described?

    <p>To catalyze the conversion of RuBP to 3-PGA</p> Signup and view all the answers

    What happens to ATP and NADPH after being utilized in the Calvin cycle?

    <p>They are regenerated for future reactions</p> Signup and view all the answers

    What drives ATP synthesis during the light-dependent reactions?

    <p>The fall of electrons through the electron transport chain</p> Signup and view all the answers

    What is the primary change occurring to P700 in Photosystem I after it receives energy from light?

    <p>P700 loses an electron to an electron acceptor</p> Signup and view all the answers

    Which statement best describes the role of P680 in Photosystem II?

    <p>P680 absorbs photons and initiates the process of electron transfer</p> Signup and view all the answers

    How does the electron transport chain affect proton movement across the thylakoid membrane?

    <p>It creates a proton gradient by moving protons into the thylakoid space</p> Signup and view all the answers

    What happens to P700 after it has accepted an electron from the electron transport chain?

    <p>P700 is reduced and can participate in light absorption again</p> Signup and view all the answers

    What is the primary reason for the existence of cyclic electron flow in photosynthesis?

    <p>To generate surplus ATP when ATP supplies are low</p> Signup and view all the answers

    Which statement accurately describes the function of photosystem I in the light reactions?

    <p>Photosystem I produces NADPH and generates ATP through cyclic flow.</p> Signup and view all the answers

    In what condition does the cyclic electron flow become more prevalent in photosynthetic cells?

    <p>When the ATP demand exceeds the available NADPH</p> Signup and view all the answers

    Which of the following best describes the role of water in photosynthesis?

    <p>Source of protons and electrons to facilitate ATP production</p> Signup and view all the answers

    What is the significance of the photoprotective role of cyclic electron flow?

    <p>It mitigates damage to photosystem proteins caused by excess light</p> Signup and view all the answers

    Which pigment molecules play a crucial role in capturing light energy for photosystems?

    <p>Chlorophyll a and b along with carotenoids</p> Signup and view all the answers

    What is the end product of the light reactions that serves as reducing power for the Calvin cycle?

    <p>NADPH</p> Signup and view all the answers

    What is the source of electrons for chloroplasts during the process of photosynthesis?

    <p>Water</p> Signup and view all the answers

    How does ATP synthesis differ between chloroplasts and mitochondria?

    <p>Protons are pumped into the thylakoid space in chloroplasts and into the intermembrane space in mitochondria</p> Signup and view all the answers

    Where does the oxygen produced during photosynthesis primarily originate?

    <p>From the splitting of water</p> Signup and view all the answers

    What type of phosphorylation occurs in chloroplasts to produce ATP?

    <p>Photophosphorylation</p> Signup and view all the answers

    Which component is pumped into the thylakoid space during the light-dependent reactions?

    <p>Protons</p> Signup and view all the answers

    In which part of the chloroplast does ATP synthesis occur during photosynthesis?

    <p>Thylakoid membrane</p> Signup and view all the answers

    What is a significant similarity between chemiosmosis in chloroplasts and mitochondria?

    <p>Both utilize ATP synthase</p> Signup and view all the answers

    What role does the proton gradient play in ATP production in chloroplasts?

    <p>It fuels the diffusion back into the stroma via ATP synthase</p> Signup and view all the answers

    What role do chlorophylls play during the light-dependent reactions of photosynthesis?

    <p>They absorb light energy to energize electrons.</p> Signup and view all the answers

    Which process establishes a proton gradient across the thylakoid membrane?

    <p>The transfer of electrons through the electron transport chain.</p> Signup and view all the answers

    During photosynthesis, why is NADP+ important?

    <p>It serves as the terminal electron acceptor.</p> Signup and view all the answers

    What is the primary energy-capturing process used by photosynthetic organisms?

    <p>Capture of free energy from sunlight.</p> Signup and view all the answers

    What connects Photosystems I and II in the process of photosynthesis?

    <p>The transfer of free energy electrons through an electron transport chain.</p> Signup and view all the answers

    In which part of the chloroplast does the Calvin cycle occur?

    <p>Stroma.</p> Signup and view all the answers

    How does ATP synthase function in the light-dependent reactions?

    <p>It synthesizes ATP from ADP and inorganic phosphate using a proton gradient.</p> Signup and view all the answers

    What happens to the electrons during the electron transport chain in chloroplasts?

    <p>They are passed to a series of electron acceptors, ultimately leading to ATP synthesis.</p> Signup and view all the answers

    What is the primary function of chloroplasts in plant cells?

    <p>Photosynthesis</p> Signup and view all the answers

    In which part of the chloroplast is chlorophyll located?

    <p>Thylakoid membrane</p> Signup and view all the answers

    How many chloroplasts are typically found per square millimeter of leaf tissue?

    <p>500,000</p> Signup and view all the answers

    What is the primary role of thylakoids within chloroplasts?

    <p>Absorption of light energy</p> Signup and view all the answers

    What is found in the stroma of a chloroplast?

    <p>Dense fluid with enzymes</p> Signup and view all the answers

    Which structure in the chloroplast facilitates the building of a proton gradient?

    <p>Thylakoid membrane</p> Signup and view all the answers

    Which of the following is NOT a component of a chloroplast?

    <p>Mitochondrial matrix</p> Signup and view all the answers

    What process occurs primarily in the chloroplasts' thylakoid membranes?

    <p>Light-dependent reactions</p> Signup and view all the answers

    Study Notes

    Photosynthesis Overview

    • Photosynthesis is the process that converts solar energy into chemical energy.
    • Autotrophs, like plants, use sunlight to create organic molecules.
    • Heterotrophs consume organic molecules created from other organisms.

    Chloroplasts

    • Chloroplasts are organelles mainly found in mesophyll cells of leaves.
    • They contain chlorophyll, a green pigment important for light absorption.
    • Chloroplasts have a double outer membrane and internal thylakoid membranes that are stacked into grana.
    • The stroma is the fluid-filled interior surrounding the thylakoid membranes.

    Photosynthesis Stages

    • Photosynthesis has two main stages: the light reactions and the Calvin cycle.
    • Light Reactions occur in the thylakoid membranes and convert light energy into chemical energy in the form of ATP and NADPH.
    • The Calvin cycle, occurring in the stroma, uses ATP and NADPH to convert CO2 into sugar (G3P).

    Light Reactions

    • Light excites electrons in chlorophyll, triggering a series of electron transport chain reactions.
    • Water is split (photolysis) in this process, releasing oxygen as a byproduct.
    • The electron transport chain generates a proton gradient across the thylakoid membrane.
    • This gradient drives ATP synthesis through chemiosmosis.
    • Electrons are passed to NADP+ to form NADPH.

    Calvin Cycle

    • Carbon dioxide (CO2) is incorporated into an existing 5-carbon molecule (RuBP) via the enzyme RuBisCo.
    • This creates a 6-carbon molecule, which immediately splits into two 3-carbon molecules (3-PGA).
    • ATP and NADPH are used to convert 3-PGA into glyceraldehyde-3-phosphate (G3P).
    • G3P is a sugar precursor for glucose production or other organic compounds.
    • RuBP is regenerated in the cycle to keep the process going.

    Alternative Carbon Fixation Pathways

    • C3 photosynthesis is the most common pathway.
    • C4 plants have a spatial separation of carbon fixation and the Calvin cycle to reduce photorespiration.
    • CAM plants temporally separate carbon fixation and the Calvin cycle to conserve water in arid environments.

    Photorespiration

    • Photorespiration is a process that occurs when rubisco uses oxygen in the Calvin cycle rather than carbon dioxide.
    • This process wastes energy and reduces photosynthetic efficiency.
    • C4 and CAM plants minimize photorespiration compared to C3 plants, primarily by fixing carbon dioxide in different compartments before the Calvin cycle.

    Summary

    • Photosynthesis efficiently converts light energy into chemical energy, making sugar and other organic molecules.
    • Light reactions establish an energy source via ATP and reducing power via NADPH.
    • These are used in the Calvin cycle to synthesize glucose and other essential compounds.
    • Adaptations to minimize photorespiration, such as those seen in C4 and CAM plants, are significant adaptations for plants thriving in diverse environments.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Chapter 8 - Photosynthesis (PDF)

    Description

    Test your knowledge on the essential processes of photosynthesis and cellular respiration. This quiz covers key concepts, including the roles of photosystems I and II, the Calvin cycle, and electron transport chains. Perfect for students wanting to reinforce their understanding of plant biology and energy production.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser