2006-2007

Photosynthesis: Life from Light and Air 2006-2007

Plants are energy producers Like animals, plants need energy to live unlike animals, plants don’t need to eat food to make that energy Plants make both FOOD & ENERGY animals are consumers plants are producers

How do plants make energy & food? Plants use the energy from the sun to make sugars glucose sun sugars

Building plants from sunlight & air Photosynthesis 2 separate processes ENERGY collection collect sun energy SUGAR building use the energy collect CO2 from air & H2O from ground use all to build sugars H2O sun + CO2 sugars carbon dioxide CO2 water H2O sugars C6H12O6 +

Plant System INPUTS OUTPUTS leaves shoot roots  light CO2 H2O O2 Sugar (glucose) leaves shoot roots 6CO2 6H2O C6H12O6 6O2 light energy  +

Make sugar! I can do it all… And no one even notices! CHLOROPLASTS This is where plants collect sunlight and make sugars. Make sugar! I can do it all… And no one even notices! sun CO2 sugars H2O

Chloroplasts are only in plants animal cells plant cells

How are plants and animals connected? Respiration glucose + oxygen  carbon + water + energy dioxide C6H12O6 6O2 6CO2 6H2O energy  + Photosynthesis So, in effect, photosynthesis is respiration run backwards powered by light. Cellular Respiration oxidize C6H12O6  CO2 & produce H2O fall of electrons downhill to O2 exergonic Photosynthesis reduce CO2  C6H12O6 & produce O2 boost electrons uphill by splitting H2O endergonic 6CO2 6H2O C6H12O6 6O2 light energy  +  glucose + oxygen carbon dioxide sun + water +

The Great Circle of Life! sun Energy cycle Photosynthesis plants H2O CO2 glucose sugars O2 animals, plants Cellular Respiration The Great Circle of Life! Mufasa?

The poetic perspective All of the solid material of every plant was built out of thin air All of the solid material of every animal was built from plant material sun air Then all the cats, dogs, mice, people & elephants… are really strands of air woven together by sunlight!

END OF NOTES Show video: The world of plants: Photosynthesis Complete the videoguide The next few slides give additional “extra” information

Putting it all together Making a living… sunlight leaves = solar collectors photosynthesis gases: CO2 in & O2 out stomates = gases in & out H2O roots take in water from soil pulled up by leaf evaporation nutrients roots take in from soil

Transpiration Water evaporates from the stomates in the leaves pulls water up from roots water molecules stick to each other more water is pulled up tree from ground

Stomates & Guard Cells guard cell stomate Function of stomates CO2 in O2 out H2O out gets to leaves for photosynthesis Function of guard cells open & close stomates guard cell stomate

Guard cells & Homeostasis keeping the internal environment of the plant balanced Stomates open let CO2 in needed to make sugar let H2O out so it gets to leaves let O2 out get rid of waste product Stomates close if too much H2O evaporating

Xylem carry water up from roots

Phloem: food-conducting cells carry sugars around the plant wherever they are needed new leaves fruit & seeds roots

organic molecules food consumers, heterotrophs release chemical energy sun Another view… capture light energy Photosynthesis synthesis producers, autotrophs H2O CO2 organic molecules food O2 waste waste waste consumers, heterotrophs digestion Cellular Respiration ATP release chemical energy