Regents Biology 2006 2007 Photosynthesis Life from Light

Regents Biology 2006 -2007

Photosynthesis: Life from Light and Air Regents Biology 2006 -2007

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

How do plants make energy & food? § Plants use the energy from the sun to make ATP energy u to make sugars u § glucose, sucrose, cellulose, starch, & more sun ATP sugars Regents Biology

Building plants from sunlight & air § Photosynthesis 2 separate processes u ENERGY building reactions sun u § collect sun energy § use it to make ATP u ATP SUGAR building reactions § take the ATP energy § collect CO 2 from air & H 2 O from ground § use all to build sugars carbon dioxide water + HO CO Regents Biology 2 2 H 2 O + CO 2 sugars C 6 H 12 O 6 sugars

Using light & air to grow plants § Photosynthesis using sun’s energy to make ATP u using CO 2 & water to make sugar u in chloroplasts u allows plants to grow u makes a waste product u § oxygen (O 2) (ATP) = used to build the sugar carbon sun + water + energy glucose + oxygen dioxide 6 CO 2 + 6 H 2 O + sun �C 6 H 12 O 6 + 6 O 2 energy Regents Biology

What do plants need to grow? § The “factory” for making energy & sugars u sun chloroplast § Fuels CO 2 sunlight u carbon dioxide u water Make ATP! Make sugar! I can do it all… And no one even notices! u § The Helpers u enzymes Regents Biology H 2 O ATP enzymes sugars

Photosynthesis sun ENERGY building reactions ATP ADP SUGAR building reactions H 2 O Regents Biology used immediately to synthesize sugars sugar CO 2

Chloroplasts are only in plants animal cells plant cells Regents Biology

Chloroplasts Leaf absorb sunlight & CO 2 Leaves sun CO 2 Chloroplasts in cell Chloroplasts contain Regents Biology Chlorophyll Chloroplast make ENERGY & SUGAR

So what does a plant need? § Bring In light u CO 2 u H 2 O u leaves § Let Out u § Move Around u shoot O 2 sugars roots 6 CO 2 + 6 H 2 O + light C 6 H 12 O 6 + 6 O 2 Regents Biology energy

Leaf Structure cuticle epidermis vascular bundle (vein) xylem (water) phloem (sugar) palisades layer spongy layer epidermis cuticle Regents Biology stomate guard cells

xylem (water) Transpiration O 2 H O 2 § CO 2 in § O 2 out § water out § so it. Biology gets Regents CO 2 stomate O 2 H 2 O to leaves from roots CO 2 guard cells

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

Function of Leaf Structures § Cuticle u waxy coating reduces water loss § Epidermis u skin protecting leaf tissues § Palisades layer u high concentration of chloroplasts § collecting sun’s energy u photosynthesis § making ATP & sugars § Spongy layer u air spaces § gas exchange w CO 2 in for sugar production, remove waste O 2 Regents Biology

Stomates & Guard Cells § Function of stomates u u u CO 2 in O 2 out H 2 O out § gets to leaves for photosynthesis § Function of guard cells u open & close stomates guard cell stomate Regents Biology

Guard cells & Homeostasis § Homeostasis u keeping the internal environment of the plant balanced § Stomates open u let CO 2 in § needed to make sugars u let H 2 O out § needed for photosynthesis u let O 2 out § get rid of waste product § Stomates close u if too much H 2 O evaporating Regents Biology

Xylem carry water up from roots Regents Biology

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

How are they connected? Respiration glucose + oxygen carbon + water + energy dioxide C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + ATP Photosynthesis carbon sun + water + glucose + oxygen energy dioxide 6 CO 2 + 6 H 2 O + light C 6 H 12 O 6 + 6 O 2 energy Regents Biology

Energy cycle sun Photosynthesis plants CO 2 glucose H 2 O sugars animals, plants Cellular Respiration The Great Circle of Life! Regents Biology Mufasa? ATP O 2

Another view… capture light energy Photosynthesis producers, autotrophs CO 2 waste sun organic O 2 molecules waste H 2 O waste food consumers, heterotrophs digestion Cellular Respiration Regents Biology release chemical energy ATP

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 air Regents Biology Then all the cats, dogs, mice, people & elephants… are really strands of air woven together by sunlight! sun

Got the energy… Ask Questions!! Regents Biology 2006 -2007