Photosynthesis and Bacterial Energetics Quiz
42 Questions
2 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 are the two main functions of photosynthesis?

  • ATP generation and NAD(P)H production (correct)
  • Light absorption and energy storage
  • Producing ATP and creating glucose
  • Water splitting and oxygen release

    • What role do accessory pigments like carotenoids play in photosynthesis?

  • They generate ATP directly through photophosphorylation.
  • They replace chlorophyll in oxygenic photosynthesis.
  • They assist in broader wavelength access for light absorption. (correct)
  • They are the primary light-capturing pigments.

    • Which molecule is primarily responsible for light absorption in photosynthesis?

  • Chlorophyll b
  • Carotene
  • Chlorophyll a (correct)
  • Bacteriophyll

    • What is the significance of CO2 fixation in photosynthesis?

    <p>It converts CO2 back into organic matter.</p> Signup and view all the answers

    What is the primary energy source for the electron transport chain in photosynthesis?

    <p>Light energy</p> Signup and view all the answers

    Which component is essential for generating ATP through photosynthesis in starved bacterial cells?

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

    What happens to chlorophyll pigments during fall, contributing to visible colors?

    <p>Chlorophyll is degraded, revealing accessory pigments.</p> Signup and view all the answers

    Which of the following statements about anoxygenic phototrophs is correct?

    <p>They utilize alternative electron donors that are not water.</p> Signup and view all the answers

    What ability allows Salmonella typhimurium to outcompete other bacteria?

    <p>Using tetrathionate as a terminal electron acceptor</p> Signup and view all the answers

    How do lactic acid bacteria (LAB) produce ATP?

    <p>By substrate level phosphorylation during glycolysis</p> Signup and view all the answers

    In the context of bioenergetics, what role does ATP synthase play?

    <p>It acts as an ATP-driven proton pump in some conditions</p> Signup and view all the answers

    Which pigment is NOT commonly found in cyanobacteria?

    <p>Chlorophyll b</p> Signup and view all the answers

    What happens to electrons released during glucose oxidation?

    <p>They flow through the electron transport chain for ATP production</p> Signup and view all the answers

    What is a product of the TCA cycle that is critical for energy production in cells?

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

    What is the primary ecological role of Prochlorococcus?

    <p>Dominant primary producer at mid latitudes</p> Signup and view all the answers

    What unique habitat can desert crust cyanobacteria thrive in?

    <p>Harsh desert environments</p> Signup and view all the answers

    Which molecule is not a primary electron acceptor in aerobic respiration?

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

    What does the term 'substrate level phosphorylation' refer to?

    <p>ATP synthesis from inorganic phosphate and ADP without a proton gradient</p> Signup and view all the answers

    Which component is essential for the non-cyclic electron flow in photosystems?

    <p>Mn4Ca site</p> Signup and view all the answers

    What characteristic of cyanobacteria allows them to be effective in oxygenic photosynthesis?

    <p>Multiple accessory pigments</p> Signup and view all the answers

    What is the final product of glucose metabolism through fermentation?

    <p>Lactic acid or ethanol</p> Signup and view all the answers

    Which of the following statements about microbial mats is true?

    <p>They can consist of various groups of microorganisms.</p> Signup and view all the answers

    What depth range does Prochlorococcus typically inhabit?

    <p>20-200 m</p> Signup and view all the answers

    What is the role of phycobilins in cyanobacteria?

    <p>Absorb light for photosynthesis</p> Signup and view all the answers

    What is the primary function of chlorosomes in green sulfur bacteria?

    <p>They improve photosynthetic efficiency under low light.</p> Signup and view all the answers

    Which electron donor is favored by green sulfur bacteria for photosynthesis?

    <p>Hydrogen sulfide (H2S)</p> Signup and view all the answers

    What distinguishes the CO2 fixation pathway in green sulfur bacteria from the RPP cycle?

    <p>It is based on a reverse tricarboxylic acid cycle.</p> Signup and view all the answers

    How do green sulfur bacteria manage to survive in environments with low light?

    <p>By developing chlorosomes.</p> Signup and view all the answers

    Which of the following statements about the electron donor crisis is true?

    <p>Anoxygenic photosynthetic bacteria were limited by available electron donors.</p> Signup and view all the answers

    In green sulfur bacteria, where do electrons flow after being released from the FeS protein?

    <p>To ferredoxin (Fd)</p> Signup and view all the answers

    Which of the following organisms were the first to fix CO2 using a pathway different from the RPP cycle?

    <p>Green sulfur bacteria</p> Signup and view all the answers

    What is a key difference between the electron flow in oxygenic photosynthesis and that in green sulfur bacteria?

    <p>Oxygenic photosynthesis uses water as an electron donor.</p> Signup and view all the answers

    What is the primary role of photons in photosynthesis?

    <p>To provide energy to eject electrons from chlorophyll.</p> Signup and view all the answers

    How does the reductive pentose phosphate (RPP) cycle function in purple bacteria?

    <p>It relies on organic electron donors for carbon fixation.</p> Signup and view all the answers

    Which of the following is true about the electron donors in oxygenic and anoxygenic photosynthesis?

    <p>Water is an unfavorable electron donor for CO2 fixation.</p> Signup and view all the answers

    What distinguishes purple sulfur bacteria from purple nonsulfur bacteria?

    <p>Production of granules from internal S0.</p> Signup and view all the answers

    What is the significance of carotenoids in purple bacteria?

    <p>They absorb light energy during photosynthesis.</p> Signup and view all the answers

    Which phylum includes both purple sulfur bacteria and purple nonsulfur bacteria?

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

    In comparison to H2O, how does H2S function as an electron donor in CO2 fixation?

    <p>H2S is a superior electron donor for CO2 fixation.</p> Signup and view all the answers

    What role does the CCCP play in bacterial metabolism?

    <p>It acts as an uncoupler that disrupts the proton gradient.</p> Signup and view all the answers

    What is the expected output from the RPP cycle when fixing 6 CO2 molecules?

    <p>1 glucose molecule and 18 ATP.</p> Signup and view all the answers

    Which of the following statements about energy requirements for photosynthesis is correct?

    <p>Anoxygenic processes use less energy due to inefficient electron donors.</p> Signup and view all the answers

    Study Notes

    Photosynthesis Lecture Notes

    • Diverse chlorophototroph bacteria are discussed.
    • Information is from Ann Rev Pl. Biol. 69:16 (2018).
    • S. Typhimurium utilizes waste products in its respiratory chain.
    • This bacterium outcompetes other bacteria due to its ability to use tetrathionate as a terminal electron acceptor, which it produces from thiosulfate found during inflammation.
    • Fermentative bacteria like lactic acid bacteria (LAB) produce ATP via substrate-level phosphorylation in glycolysis.
    • LAB still require a proton motive force (PMF) for transport, ion balance, and sometimes motility.
    • LAB use F₁F₀ ATPase in reverse as an ATP-driven proton pump.
    • ATPase/synthase is reversible, acting like a pump or a water wheel.
    • Bioenergetics involves electron transport chain moving electrons from donor to acceptor, outside the cell to the inside.
    • Glucose is converted to CO₂ releasing electrons, these are then used in the electron transport chain (oxidative phosphorylation) creating a large amount of ATP.
    • The next step after glucose and pyruvate and acetyl CoA is the conversion to CO₂ in the TCA cycle.
    • The main functions of photosynthesis include ATP generation via the electron transport chain which is light-driven and production of NAD(P)H for anabolic reactions, like CO₂ fixation, also light-driven.

    Chlorophyll and Bacteriochlorophyll

    • Chlorophyll a and bacteriochlorophyll a are key molecules in photosynthesis for many anoxygenic phototrophs.
    • These molecules have absorption spectra in the visible and near-infrared region, with differences related to the organism's specific pigment.
    • These pigments are often associated with accessory pigments or proteins which broaden the wavelength absorption spectra.

    Carotenoids

    • Carotenoids are accessory pigments that absorb light energy and increase the range of wavelengths that can be utilized by photosynthetic organisms.
    • Carotenoids are isoprenoids with conjugated double bonds and include beta-carotene, lycopene, and chlorobactene.

    Photosynthetic Bacteria

    • There exist 7 phyla with photosynthetic members.
    • Oxygenic photosynthesis includes cyanobacteria.
    • Anoxygenic photosynthesis includes purple bacteria, green sulfur bacteria, green nonsulfur bacteria, heliobacteria, chloracidobacteria, and gemmatomonas.

    More on Photosystems

    • Purple bacteria fix CO₂ using the reductive pentose phosphate (RPP), or Calvin cycle, same as plants and cyanobacteria.
    • The RPP cycle requires 18 ATP for each CO₂ fixed.
    • In all photosynthesis systems, the quinol/quinone pool has a key role in proton motive force ATP generation.
    • Light energy converts a weak electron donor into a strong electron donor in purple bacteria.
    • An example in bacterial mats are microbial communities, found with layers of photosynthetic bacteria.

    Electron Donor Crisis

    • Anoxygenic photosynthetic bacteria use alternative electron donors available on early Earth, such as H₂S and Fe²⁺.
    • Oxygenic photosynthesis uses water (H₂O) as an electron donor, allowing for the conversion of CO₂ into sugars.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Photosynthesis Lecture 24 Lecture Notes PDF

    Description

    Test your knowledge on the fundamental processes of photosynthesis, including functions, pigments, and energy production. Explore the role of bacteria in bioenergetics and their competitive abilities within ecological systems. This quiz covers crucial concepts used in advanced biology and environmental studies.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser