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Unformatted text preview: nts abs orb more s trongly in the red and blue parts of the s pec trum and les s s trongly in the y ellow and green parts .
He als o did not as s ume that all abs orbed photons driv e photos y nthes is , and thus ox y gen produc tion, by the alga. In fac t, all photos y nthetic
organis ms c ontain s ome pigments that abs orb photons but do not c ontribute to photos y nthes is or ox y gen produc tion. Part C Experimental prediction: T he action spectrum
One of the as s umptions that Engelmann made was that the s un (his light s ourc e) emits equal numbers of photons at eac h wav elength in the v is ible
s pec trum. In reality , the s un’s emis s ion peak s in the y ellow region of the s pec trum, with relativ ely fewer photons emitted in the red and v ioletblue
regions . se ssion.ma ste r ingbiology.c om/myc t/a ssignme ntPr intVie w? a ssignme ntI D= 2242937 10/41 13- 10- 13 Cha pte r 10 Rec all that the ac tion s pec trum from Engelmann’s ex periment plotted the rate of photos y nthes is (as meas ured by ox y gen produc tion) v ers us
wav elength. In eac h of the following graphs , the blac k line s hows Engelmann’s original ac tion s pec trum deduc ed from the dis tribution of aerotac tic
bac teria around the alga.
Which red line shows the sam e action spectrum corrected for the unequal num ber of photons em itted across the visible spectrum ? Hin t 1. How to approach the problem
Keep in mind that Engelmann’s ac tion s pec trum was bas ed on his ex periment us ing s unlight, whic h c ontains unequal amounts of photons
ac ros s the v is ible s pec trum. In this problem, y ou hav e been c hallenged to c orrec t his ac tion s pec trum for the unequal emis s ion of photons in
different wav elengths of the s pec trum. To do s o, y ou need to determine how the line would s hift if the number of photons emitted in the red and
v ioletblue parts of the s pec trum inc reas ed to equal the number of photons emitted in the y ellow part.
Think about how inc reas ing the number of photons in the red and v ioletblue parts of the s pec trum would affec t the rate of photos y nthes is in the
alga. How would that affec t the amount of ox y gen produc...
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This document was uploaded on 02/17/2014 for the course BIOCHEMIST 2550 at Ohio State.
- Spring '14