Chapter 8.pdf

9/8/2023 Chapter 8— Plant Physiology and Growth Key Concepts Photosynthesis converts sunlight to chemical energy Respiration converts carbohydrates to energy Transpiration is water loss from stomata Symbiotic nitrogen fixation is the process that makes atmospheric N available Photoperiodism is a rea...

9/8/2023 Chapter 8— Plant Physiology and Growth Key Concepts Photosynthesis converts sunlight to chemical energy Respiration converts carbohydrates to energy Transpiration is water loss from stomata Symbiotic nitrogen fixation is the process that makes atmospheric N available Photoperiodism is a reaction to changing lengths of darkness I yr zyr Plants are categorized as annual, biennial, and perennial 3t yr The Leaf Dicot Branched veins · http://micro.magnet.fsu.edu/cells/leaftissue/images/leafstructurelargefigure1.jpg 1 9/8/2023 The Plant Cell and Chloroplast · cell wall gives structure http://micro.magnet.fsu.edu/cells/chloroplasts/images/chloroplastsfigure1.jpg http://www.uvm.edu/~inquiryb/webquest/fa06/mvogenbe/plantcell.jpg Water · · Carbon goes through xylem dioxide in/comes out : Oxygen goes ofStomata http://static.howstuffworks.com/gif/irrigation-photosynthesis.gif Photosynthesis Process in which energy from sunlight is chemicalenergy converted to chemical energy Energy used for other metabolic processes Takes place in the chloroplast Chemical reaction of photosynthesis is: 6 CO2 + 12 H2O + Sunlight  C6H12O6 + 6 O2 + 6 H2O ↑ carbon dioxide water light glucose ofggen water 2 9/8/2023 Photosynthesis (continued) Light reactions – First part of photosynthesis – Only ones actually requiring light – Photons strike chlorophyll and set off chain of reactions O ATP * APH http://kjemily.com/stellar/CERES/pics/describe.jpg Photosynthesis (continued) fixation Carbon-fixation reactions – CO2 diffuses through stomata into chloroplast – NADPH and ATP made in light reaction power reduction of CO2 to simple sugars – Calvin cycle or C3 cycle Rubisco captures CO2 CO gets pulled apart for sugar (glucose) · , · When Rubisco Called pulls in Oxygen Photo resperation (negative want this) its , , don't http://img.sparknotes.com/101s/biology/calvin_cycle.jpg Variations in the Carbon Fixation Alternative systems of carbon fixation – Cy C4 Adapted to hot temperatures Different leaf anatomy – CAM C Uses the C4 pathway at night and the C3 pathway in the day Adapted to hot temperatures /Cactus succulents) , Majority of temperate plants are C3 3 Heuris Wheel * - - - · C3 vs C4 CCa C4 3 C4 No distinct bundle sheath Bundle sheath cells Rubisco PEP carboxylase + Rubisco in PEP( ) Photorespiration Coxy getting CO2 No photorespiration /bc of than rather Optimum: 15-25°C Optimum: 30-47°C Minimum CO2: 30-70 ppm Minimum CO2: 0-10 ppm ~60% light efficiency Nearly 100% light efficiency Wheat, cotton, peanut, Corn, sorghum, millet, alfalfa, potato, rice, tobacco switchgrass, big bluestem, bermudagrass. L. Rubisco CO2 PEP is ms. right Carboxylase Rubisco pulls oxygen , it is analogy the "seat" is , is in O - is the 9/8/2023 pubisco "Man look forms. not lugly girl) buddy CO that sorts the or right /102)" "ugly" loxygen O-if called Photo respiration" is has Notgood/desired.P&P Carboxylasee - /Only in 44 plants) The Plant Cell & Mitochondria www.cartage.org.lb/.../Mitochondria.htm http://www.uvm.edu/~inquiryb/webquest/fa06/mvogenbe/plantcell.jpg Respiration Conversion of sugars sugars from photosynthesis to energy for use in metabolism Occurs in both the cytoplasm and the mitochondria Reaction is: C6H12O6 + 6 O2  6 CO2 + 6 H2O + Energy (ATP and heat) 4 9/8/2023 - Transpiration Iranspiration Process of water loss from stomata Corn and sunflower can transpire from ½ to - - Growth and Development irreversible increase in weight or size Growth—irreversible due to increase in number and size of cells Development—when plants transition transition from germination, seedling, vegetative, flowering, and seed Growth can be measured as dry matter accumulation Development can be measured using scales Management decisions… 7 9/8/2023 Growth and Development Plant Life Cycles Annual Annual—complete life cycle in one year or one growing season · these to are produce about how a seed long it takes Spring/summer Winter Biennial—complete life two growing seasons cycle in two I years) Plant Life Cycles (cont.) Perennial—persist for three or more years or growing seasons Pseudo-annual—perennial and biennial Pseudo-annual plants managed as annuals 8