Division Ave. High School AP Biology

Transcription

1 Photosynthsis: Lif from Light and Air Enrgy nds of lif All lif nds a constant input of nrgy u Htrotrophs (Animals) gt thir nrgy from ating othrs consumrs w at food = othr organisms = organic molculs mak nrgy through rspiration u Autotrophs (Plants) produc thir own nrgy (from slf ) convrt nrgy of sunlight producrs build organic molculs (CHO) from CO 2 mak nrgy & synthsiz sugars through photosynthsis 1

2 How ar thy connctd? Htrotrophs making nrgy & organic molculs from ingsting organic molculs glucos oxygn carbon watr nrgy dioxid C 6 H 12 O 6 6O 2 6CO 2 6H 2 O oxidation = xrgonic Autotrophs making nrgy & organic molculs from light nrgy carbon watr nrgy glucos oxygn dioxid 6CO 2 6H 2 O light C 6 H 12 O 6 6O nrgy 2 rduction = ndrgonic Whr s th? What dos it man to b a plant Nd to u collct light nrgy transform it into chmical nrgy u stor light nrgy in a stabl form to b movd around glucos th plant or stord u nd to gt building block atoms from th nvironmnt C,H,O,N,P,K,S,Mg u produc all organic molculs ndd for growth CO 2 N K P carbohydrats, protins, lipids, nuclic acids H 2 O Plant structur Obtaining raw matrials u sunlight lavs = solar collctors u CO 2 stomats = gas xchang u H 2 O uptak from roots u nutrints N, P, K, S, Mg, F uptak from roots 2

3 stomat ütranspiration ügas xchang lavs Chloroplasts cross sction of laf absorb sunlight & CO 2 CO 2 chloroplasts in plant cll chloroplast chloroplasts contain chlorophyll mak nrgy & sugar Plant structur Chloroplasts u doubl mmbran u stroma fluid-filld intrior u thylakoid sacs stroma u grana stacks Thylakoid mmbran contains u chlorophyll molculs u lctron transport chain u synthas gradint built up within thylakoid sac chloroplast H H H H H thylakoid outr mmbran thylakoid granum innr mmbran 3

4 Photosynthsis Light ractions u light-dpndnt ractions u nrgy convrsion ractions convrt solar nrgy to chmical nrgy & NADPH Calvin cycl u light-indpndnt ractions u sugar building ractions It s not th Dark Ractions! uss chmical nrgy ( & NADPH) to rduc CO 2 & synthsiz C 6 H 12 O 6 Light ractions Elctron Transport Chain lik in cllular rspiration u protins in organll mmbran u lctron accptors NADPH u proton ( ) gradint across innr mmbran find th doubl mmbran! u synthas nzym chloroplast thylakoid H H H H H H ETC of Rspiration Mitochondria transfr chmical nrgy from food molculs into chmical nrgy of u us lctron carrir NADH gnrats H 2 O 4

5 ETC of Photosynthsis Chloroplasts transform light nrgy into chmical nrgy of u us lctron carrir NADPH gnrats O 2 Th that Jack built photosynthsis rspiration sunlight brakdown of C 6 H 12 O 6 H movs th lctrons runs th pump pumps th protons builds th gradint drivs th flow of protons through synthas ADP P i bonds P i to ADP gnrats th that volution built Pigmnts of photosynthsis Chlorophylls & othr pigmnts u mbddd in thylakoid mmbran u arrangd in a photosystm collction of molculs u structur-function rlationship How dos this molcular structur fit its function? 5

6 A Look at Light Th spctrum of color V I B G Y O R Light: absorption spctra Photosynthsis gts nrgy by absorbing wavlngths of light u chlorophyll a absorbs bst in rd & blu wavlngths & last in grn u accssory pigmnts with diffrnt structurs absorb light of diffrnt wavlngths chlorophyll b, carotnoids, xanthophylls Why ar plants grn? Photosystms of photosynthsis 2 photosystms in thylakoid mmbran u collctions of chlorophyll molculs u act as light-gathring molculs u Photosystm II raction chlorophyll a cntr P 680 = absorbs 680nm wavlngth rd light u Photosystm I chlorophyll b P 700 = absorbs 700nm wavlngth rd light antnna pigmnts 6

7 chlorophyll a Photosystm II ETC of Photosynthsis chlorophyll b Photosystm I ETC of Photosynthsis sun 1 Photosystm II P680 chlorophyll a Inhal, baby! ETC of Photosynthsis chloroplast thylakoid H H H H H H Plants SPLIT watr! 2 1 O H O H H H Photosystm II P680 chlorophyll a fill th vacancy - - H 7

8 H Division Av. High School ETC of Photosynthsis chloroplast thylakoid H H H H H H H to Calvin Cycl nrgy to build carbohydrats Photosystm II P680 chlorophyll a ADP P i ETC of Photosynthsis sun 5 Photosystm II P680 chlorophyll a Photosystm I P700 chlorophyll b ETC of Photosynthsis lctron carrir 6 5 sun Photosystm II P680 chlorophyll a Photosystm I P700 chlorophyll b $$ in th bank rducing powr! 8

9 ETC of Photosynthsis sun sun split H 2 O O H H H to Calvin Cycl ETC of Photosynthsis ETC uss light nrgy to produc u & NADPH go to Calvin cycl PS II absorbs light u xcitd lctron passs from chlorophyll to primary lctron accptor u nd to rplac lctron in chlorophyll u nzym xtracts lctrons from H 2 O & supplis thm to chlorophyll splits H 2 O O combins with anothr O to form O 2 O 2 rlasd to atmosphr and w brath asir! Exprimntal vidnc Whr did th O 2 com from? u radioactiv tracr = O 18 Exprimnt 1 6CO 2 6H 2 O light C 6 H 12 O 6 6O nrgy 2 Exprimnt 2 6CO 2 6H 2 O light C 6 H 12 O 6 6O nrgy 2 AP Provd Biology O 2 cam from H 2 O not CO 2 = plants split H 2 O! 9

10 Noncyclic Photophosphorylation Light ractions lvat lctrons in 2 stps (PS II & PS I) u PS II gnrats nrgy as u PS I gnrats rducing powr as NADPH Cyclic photophosphorylation If PS I can t pass lctron to NADP it cycls back to PS II & maks mor, but no NADPH u coordinats light ractions to Calvin cycl u Calvin cycl uss mor than NADPH NADPH 1 C 6 H 12 O 6 Photophosphorylation cyclic photophosphorylation NADP NONcyclic photophosphorylation 10

11 Division Av. High School Photosynthsis summary Whr did th nrgy com from? Whr did th lctrons com from? Whr did th H2O com from? Whr did th O2 com from? Whr did th O2 go? Whr did th H com from? Whr did th com from? What will th b usd for? Whr did th NADPH com from? What will th NADPH b usd for? stay tund for th Calvin cycl You can grow if you Ask Qustions! Ghosts of Lcturs Past (storag)

12 Stomats 12