bio 113 photo energy 03

8/4/2019 Bio 113 Photo Energy 03

1/66

Biology 113


2/66

Photosynthesis:Transformationof Energy


3/66

History of Photosynthesis; Lightand Color


4/66


5/66


6/66

OBJECTIVES:


7/66

To un erstan t e as c conceptsassociated with energy

transformations,


8/66

nc u ng t e Laws oThermodynamics that govern

energy transformations.


9/66

To understand the chemical natureof photosynthesis.


10/66

To understand the history of ourunderstanding of photosynthesis.


11/66

To master basic concepts associatedwith the nature of light


12/66

To understand how pigments work.


13/66

To understand how photosynthesisevolved.


14/66

Energy


15/66

potential energy vs. kineticenergy


16/66

kinds of energy - thermal, light,electrical, mechanical, chemical

F L T


17/66

F rst Law o T ermo ynam cs(Law of the Conservation of

Energy)


18/66

Second Law of Thermodynamics(Law of Entropy)


19/66

exergon c vs. en ergon c c em careactions; enzymes, coenzymes and

cofactors


20/66

energy in open vs. closed systems


21/66


22/66

Chemical Nature of Photosynthesis

O R R


23/66

Ox at on - Re uct on React onsin General


24/66

chlorophyll

CO2 + 2H2O >


25/66

CO2 + 2H2O --------->C6H12O6 + 6O2 + 6H2O ;

Equation for Photosynthesis


26/66

light


27/66


28/66

Enzymes, cofactors and coenzymes


29/66

energy of activation


30/66

TP DP t e n ers energ


31/66

TP DP t e un versa energyexchange system in living

organisms

coup e react ons: en ergon c rxn


32/66

coup e react ons: en ergon c rxn+ ATP + ATPase --> exergonic

reaction


33/66


34/66

History of Photosynthesis


35/66

van Helmont's willow treeexperiments (1648?)


36/66

Priestley's method of "restoringair" (1771)

Ingen ousz exper ments g t are


37/66

Ingen ousz exper ments - g t aregreen plants are necessary for

restoring air (1778)


38/66

Englemann's experiment (1882)


39/66

van Niel's observations (1920's):

CO2 + 2 H2S =>


40/66

CO2 + 2 H2S --------=>C6H12O6 + 12S + 6H2O purple

sulfur bacteria


41/66

light

H React on so ate


42/66

H React on so atechloroplasts if given an electron

acceptor will generate 02

Ru en an Kamen ver y t at t e


43/66

Ru en an Kamen - ver y t at t eO2 in photosynthesis comes from

water (1941)


44/66


45/66

Light


46/66

electromagnetic spectrum =radiant energy

gamma - X-rays - UV - v o et -


47/66

gamma - X-rays - UV - v o et -blue - green - yellow - orange - red

- infrared - radio

3 nm


48/66

3 nm500 nm 750 nm

10

v s e g t - 3 -7 nm -


49/66

v s e g t - 3 -7 nm -biologically active (some use

infrared & some use UV)

g t as a wave p enomenon;


50/66

g t as a wave p enomenon;velocity (speed of light) =

wavelength X frequency

g t as a part c e; energy =


51/66

g t as a part c e; energy =Plancks constant X speed of light /

wavelength


52/66

photons and quanta of light


53/66


54/66

Chlorophyll and light absorption

i b h b b


55/66

pigment - a substance that absorbsvisible light

porp yr n r ng con ugate on s


56/66

porp yr n r ng con ugate on suniting 4 pyrole rings around a

central chlorophyll

mo ecu e w t a ong nso u e


57/66

mo ecu e, w t a ong nso u ecarbon-hydrogen chain which

anchors the molecule)

g t a sorpt on --> eat or eat


58/66

g t a sorpt on > eat or eatand light (fluorescence) or

resonance energy transfer or

t f f hi h l t


59/66

transfer of a high-energy electron(leaving an electron hole)

a sorpt on spectrum or c . a,


60/66

a sorpt on spectrum or c . a,chl. b, and carotenoids (carotenes

and xanthophylls)

ti t f


61/66

action spectrum forphotosynthesis

accessory p gments n K ng om


62/66

accessory p gments n K ng omPlantae - chl. b, carotenes,

xanthophylls

mot e aquat c acter a,


63/66

mot e aquat c acter a,bacteriorhodopsin and evolution of

photosynthesis


64/66

color


65/66


66/66

bio 113 photo energy 03

Documents