DOC PREVIEW
UT Knoxville BIOL 140 - Chapter 10

This preview shows page 1-2-3-19-20-39-40-41 out of 41 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 41 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Chapter 10 – PhotosynthesisAn Overview of PhotosynthesisPhotosynthesis: Two Linked Sets of ReactionsSlide 4The Structure of the ChloroplastSlide 6The Nature of Light EnergyThe Electromagnetic SpectrumSlide 9Photosynthetic Pigments Absorb LightEach Pigment Has a Specific Absorption SpectrumSlide 12The Role of Carotenoids and Other Accessory PigmentsSlide 14Slide 15PhotosystemsThe Antenna ComplexThe Reaction CenterChemiosmosis and PhotophosphorylationSlide 20Slide 21***Summary of Photosystems I and II***The Location of Photosystem I and Photosystem IISlide 24The Calvin Cycle and Carbon FixationThe Calvin CycleThe Calvin CycleSlide 28The Importance of RubiscoPhotorespirationSlide 31Slide 32Carbon Dioxide Enters Leaves through StomataSlide 34Plants Must Balance Water Preservation and CO2 DeliveryMechanisms for Increasing CO2 ConcentrationThe Regulation of PhotosynthesisThe Fate of Sugar Produced by PhotosynthesisSlide 39Key ConceptsSlide 41© 2011 Pearson Education, Inc.Chapter 10 – Photosynthesis© 2011 Pearson Education, Inc.An Overview of Photosynthesis•Photosynthesis is the process of using sunlight to produce carbohydrate. This process requires sunlight, carbon dioxide, and water, and produces oxygen as a by-product. The overall reaction when glucose is the carbohydrate can be written as:6 CO2 + 12 H2O + light energy  C6H12O6 + 6 O2 + 6 H2O•Photosynthesis contrasts with cellular respiration.–Photosynthesis is endergonic.–Reduces CO2 to sugar–Cellular respiration is exergonic.–Oxidizes sugar to CO2© 2011 Pearson Education, Inc.Photosynthesis: Two Linked Sets of ReactionsPhotosynthesis consists of two linked sets of reactions: light-dependent reactions produce O2 from H2O, and Calvin cycle reactions produce sugar from CO2.•The reactions are linked by electrons, which are released in the light-dependent reactions when water is split to form oxygen gas and then transferred to the electron carrier NADP+, forming NADPH. The Calvin cycle then uses these electrons and the potential energy in ATP to reduce CO2 to make sugars.© 2011 Pearson Education, Inc.© 2011 Pearson Education, Inc.The Structure of the Chloroplast •Photosynthesis occurs in the chloroplasts of green plants, algae, and other photosynthetic organisms.•Chloroplasts are surrounded by two membranes.•The internal membranes of chloroplasts form flattened, vesicle-like structures called thylakoids, some of which form stacks called grana. –Thylakoid membranes contain large quantities of pigments.–The most common pigment is chlorophyll.•The fluid-filled space between the thylakoids and the inner membrane is the stroma.© 2011 Pearson Education, Inc.© 2011 Pearson Education, Inc.The Nature of Light Energy•Electromagnetic radiation is a form of energy.•Light is a type of energy electromagnetic radiation that acts both particle-like and wave-like.–As a particle, light exists in discrete packets called photons.–As a wave, light can be characterized by its wavelength – the distance between two successive wave crests.© 2011 Pearson Education, Inc.The Electromagnetic Spectrum•The electromagnetic spectrum is the range of wavelengths of electromagnetic radiation. •Electromagnetic radiation that humans can see is called visible light.•Each photon and wavelength has a specific amount of energy. The energy of a photon of light is inversely proportional to its wavelength. –Shorter wavelengths such as ultraviolet light have more energy than longer wavelengths such as infrared light.© 2011 Pearson Education, Inc.© 2011 Pearson Education, Inc.Photosynthetic Pigments Absorb Light•Photons may be absorbed, transmitted, or reflected when they strike an object.•Pigments are molecules that absorb only certain wavelengths of light. •There are two major classes of pigment in plant leaves: chlorophylls and carotenoids. –The chlorophylls (chlorophyll a and chlorophyll b) absorb red and blue light and reflect and transmit green light. –The carotenoids absorb blue and green light and reflect and transmit yellow, orange, and red light.© 2011 Pearson Education, Inc.Each Pigment Has a Specific Absorption Spectrum•Biologists use a graph called an absorption spectrum to study pigments. This spectrum plots the wavelength of light absorbed by pigment molecules. •An action spectrum shows the rate of photosynthesis vs. wavelength. –Pigments that absorb blue and red photons are the most effective at driving photosynthesis.–Because the chlorophylls absorb these wavelengths, they are most likely the main photosynthetic pigments.© 2011 Pearson Education, Inc.© 2011 Pearson Education, Inc.The Role of Carotenoids and Other Accessory Pigments•Carotenoids are accessory pigments that absorb light and pass the energy on to chlorophyll.–Carotenoids are classified into two groups – carotenes and xanthophylls.•Carotenoids absorb wavelengths of light not absorbed by chlorophyll, thus extending the range of wavelengths that can drive photosynthesis. •Carotenoids also stabilize free radicals, protecting chlorophylls from damage.© 2011 Pearson Education, Inc.•Chloroplasts generate a proton gradient _____. 1. across the thylakoid membrane2. across the plasma membrane3. in the stoma4. in the stomata© 2011 Pearson Education, Inc.•What are the metabolic end products of the light reactions of photosynthesis? 1. glucose + O22. glucose + CO23. O2, ATP, and NADPH4. ATP© 2011 Pearson Education, Inc.Photosystems•Chlorophyll molecules work together in groups, forming a complex called a photosystem.•A photosystem consists of two major elements, an antenna complex and a reaction center, as well as proteins that capture and process excited electrons.© 2011 Pearson Education, Inc.The Antenna Complex•The photosystem’s antenna complex is composed of accessory pigment molecules. •When a red or blue photon strikes a pigment molecule in the antenna complex, the energy is absorbed and an electron excited. This energy is passed to another chlorophyll molecule, exciting another electron.–This phenomenon is called resonance.•Energy is transferred inside the antenna complex, from one molecule to the next, until it reaches the reaction center.© 2011 Pearson Education, Inc.The Reaction Center•At the reaction center, excited electrons are transferred to a specialized chlorophyll molecule that acts as an electron acceptor. •When this electron acceptor becomes reduced, the electromagnetic


View Full Document

UT Knoxville BIOL 140 - Chapter 10

Download Chapter 10
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Chapter 10 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Chapter 10 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?