Transcript
8. Photosynthesis
http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG
http://www.youtube.com/watch?v=sQK3Yr4Sc_k
WHAT DO CELLS USE ENERGY FOR ?
ACTIVE TRANSPORT
Na+ - K + PUMPEndocytosisExocytosis
Energy and Life
WHAT DO CELLS USE ENERGY FOR ?
MovementSynthesis of
biomolecules Reproduction
Meiosis: http://www.tokyo-med.ac.jp/genet/anm/Cilia: http://www.sk.lung.ca/content.cfm?edit_realword=hwbreatheReplication: http://www.beyondbooks.com/lif71/4c.aspTranscription:http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/mRNA.gifTranslation:
ATP
ATP
ONE SPECIAL KIND of NUCLEOTIDE is used by cells to store and transport ENERGY
CELLS USE ATP TO STORE and RELEASE ENERGY
ATP = __________________________Adenosine triphosphate
____ PHOSPHATE GROUPS
3
ATP can change into ADP
ADP = __________________________Adenosine diphosphate
____ PHOSPHATE GROUPS
2
ATP → ____ + ____ +
ATP releases energy stored in a high energychemical bond by removing the phosphate and becoming ADP
ADP
ADP + ___ + ________ → ___
The energy to do this comes from____________ like _____________
Cells ________ energy by adding the phosphate back on to ADP to make ATP.
ATP
It’s like recharging the battery !
STORE
FOODS GLUCOSE
_____________ can make their own food usingenergy from sunlight.
Ex: Green plants, a few bacteria
Autotrophs
__________________ get energy by consumingother organisms
Ex: Animals, fungi, most bacteria
Heterotrophs
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)
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Leaves and Photosynthesis
How Leaves Work
LIGHT-DEPENDENT REACTIONS
See an animation about the ELECTRON TRANSPORT CHAIN
Pearson Education Inc; Publishing as Pearson Prentice Hall
SEE A MOVIEATP SYNTHASEIN ACTION
http://www.stolaf.edu/people/giannini/flashanimat/metabolism/atpsyn1.sw
http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf
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Light Reactions:Noncyclic Electron
Pathway
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Light Reactions:
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 cellNADP+, 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
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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
• RuBP Regeneration
CALVIN CYCLE (also called _________________________)
____________ require ____________
Happens in _________ between thylakoidsNADPH donates _______________
ATP donates _________________CO2 donates ______________
to make __________
LIGHT
LIGHT INDEPENDENT
ENERGY
STROMAHydrogen + electrons
Carbon & oxygenGLUCOSE
http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html
DOES NOT
CO2 Enters the Cycle
Energy Input
5-CarbonMoleculesRegenerated
Sugars and other compounds
6-Carbon SugarProduced
Calvin Cycle
Photosynthesis
includes
of
take place intakes place in uses
to produce to produce
use
Section 8-3
Concept Map
Photosynthesis
includes
of
take place intakes place in uses
to produce to produce
use
Light-dependentreactions
Calvin cycle
Thylakoidmembranes Stroma NADPHATPEnergy from
sunlight
ATP NADPH O2 Chloroplasts High-energysugars
Section 8-3
Concept Map
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Photosynthesis Overview
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
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