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8. Photosynthesis http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG http://www.youtube.com/watch?v=sQ K3Yr4Sc_k Energy and Life WHAT DO CELLS USE ENERGY FOR ? ACTIVE TRANSPORT Na+ - K + PUMP Endocytosis Exocytosis WHAT DO CELLS USE ENERGY FOR ? Movement Synthesis of biomolecules Reproduction Meiosis: http://www.tokyo-med.ac.jp/genet/anm/ Cilia: http://www.sk.lung.ca/content.cfm?edit_realword=hwbreathe Replication: http://www.beyondbooks.com/lif71/4c.asp Transcription:http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/mRNA.gif Translation: ATP ONE SPECIAL KIND of NUCLEOTIDE is used by cells to store and transport ENERGY ATP CELLS USE ATP TO STORE and RELEASE ENERGY 3 PHOSPHATE ____ GROUPS Adenosine triphosphate ATP = __________________________ ATP can change into ADP 2 PHOSPHATE ____ GROUPS Adenosine diphosphate ADP = __________________________ ATP releases energy stored in a high energy chemical bond by removing the phosphate and becoming ADP ATP ADP + ____ + → ____ Cells ________ STORE energy by adding the phosphate back on to ADP to make ATP. The energy to do this comes from FOODS like _____________ GLUCOSE ____________ It’s like recharging the battery ! ADP + ___ + ________ ATP → ___ Autotrophs _____________ can make their own food using energy from sunlight. Ex: Green plants, a few bacteria Heterotrophs __________________ get energy by consuming other organisms Ex: Animals, fungi, most bacteria Photosynthesis Photosynthesis • a metabolic pathway that converts light energy into chemical energy. • is the process by which plants, some bacteria, and some protists use the energy from sunlight to produce sugar. Photosynthesis Photosynthesis Method of converting sun energy into chemical energy usable by cells Autotrophs: self feeders, organisms capable of making their own food – – Photoautotrophs: use sun energy e.g. plants photosynthesis-makes organic compounds (glucose) from light Chemoautotrophs: use chemical energy e.g. bacteria that use sulfide or methane chemosynthesis-makes organic compounds from chemical energy contained in sulfide or methane Photosynthesis Photosynthesis takes place in specialized structures inside plant cells called chloroplasts – Light absorbing pigment molecules e.g. chlorophyll Chloroplasts containing chlorophyll. Chloroplast Chloroplast Chlorophyll Visible Spectrum Photosynthetic Pigments 6H2O + 6CO2 C6H12O6 + 6O2 (water) + (carbon dioxide) + (light) (sugar) + (oxygen) Leaves and Photosynthesis 24 How Leaves Work Pearson Education Inc; Publishing as Pearson Prentice Hall LIGHT-DEPENDENT REACTIONS See an animation about the ELECTRON TRANSPORT CHAIN SEE A MOVIE ATP SYNTHASE IN ACTION http://www.stolaf.edu/people/giannini/flashanimat/metabolism/atpsyn1.sw http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf Noncyclic Electron Pathway 27 Light Reactions: 28 Light-dependent Reactions Overview: light energy is absorbed by chlorophyll molecules-this light energy excites electrons and boosts them to higher energy levels. They are trapped by electron acceptor molecules that are poised at the start of a neighboring transport system. The electrons “fall” to a lower energy state, releasing energy that is harnessed to make ATP Energy Shuttling Recall ATP: cellular energy-nucleotide based molecule with 3 phosphate groups bonded to it, when removing the third phosphate group, lots of energy liberated= superb molecule for shuttling energy around within cells. Other energy shuttles-coenzymes (nucleotide based molecules): move electrons and protons around within the cell NADP+, NADPH NAD+, NADP FAD, FADH2 Light-dependent Reactions Photosystem: light capturing unit, contains chlorophyll, the light capturing pigment Electron transport system: sequence of electron carrier molecules that shuttle electrons, energy released to make ATP Electrons in chlorophyll must be replaced so that cycle may continue-these electrons come from water molecules, Oxygen is liberated from the light reactions Light reactions yield ATP and NADPH used to fuel the reactions of the Calvin cycle (light independent or dark reactions) Calvin Cycle (light independent or “dark” reactions) ATP and NADPH generated in light reactions used to fuel the reactions which take CO2 and break it apart, then reassemble the carbons into glucose. Called carbon fixation: taking carbon from an inorganic molecule (atmospheric CO2) and making an organic molecule out of it (glucose) Simplified version of how carbon and energy enter the food chain Calvin Cycle Reactions: Overview of C3 Photosynthesis • A cyclical series of reactions • Utilizes atmospheric carbon dioxide to produce carbohydrates • Known as C3 photosynthesis • Involves three stages: • Carbon dioxide fixation • Carbon dioxide reduction 35 • RuBP Regeneration CALVIN CYCLE (also called _________________________) LIGHT INDEPENDENT DOES NOT LIGHT ____________ require ____________ Happens in _________ between thylakoids STROMA NADPH donates _______________ Hydrogen + electrons ATP donates _________________ ENERGY CO2 donates ______________ Carbon & oxygen to make __________ GLUCOSE http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html Calvin Cycle CO2 Enters the Cycle Energy Input 5-Carbon Molecules Regenerated 6-Carbon Sugar Produced Sugars and other compounds Concept Map Section 8-3 Photosynthesis includes use to produce takes place in take place in of uses to produce Concept Map Section 8-3 Photosynthesis includes Lightdependent reactions Calvin cycle use take place in Energy from sunlight Thylakoid membranes to produce ATP NADPH O2 takes place in Stroma uses ATP NADPH of to produce Chloroplasts High-energy sugars Photosynthesis Overview 40 Harvesting Chemical Energy So we see how energy enters food chains (via autotrophs) we can look at how organisms use that energy to fuel their bodies. Plants and animals both use products of photosynthesis (glucose) for metabolic fuel Heterotrophs: must take in energy from outside sources, cannot make their own e.g. animals When we take in glucose (or other carbs), proteins, and fats-these foods don’t come to us the way our cells can use them