This preview shows page 1. Sign up to view the full content.
Unformatted text preview: formed.
The primary elec tron ac c eptor of PS I mus t be reduc ed. ANSWER: se ssion.ma ste r ingbiology.c om/myc t/a ssignme ntPr intVie w? a ssignme ntI D= 2242937 17/41 13- 10- 13 Cha pte r 10 Correct
In both PS II and PS I, light energy is us ed to driv e a redox reac tion that would not otherwis e oc c ur. In eac h photos y s tem, this redox reac tion
mov es an elec tron from the s pec ial c hlorophy ll pair (P680 in PS II and P700 in PS I) to that photos y s tem’s primary elec tron ac c eptor.
The res ult in eac h c as e is a reduc tant (the reduc ed primary elec tron ac c eptor) and an ox idant (P680+ in PS II and P700+ in PS I) that are able to
power the res t of the elec tron trans fer reac tions without further energy input. Part C Proton gradient formation and AT P synthesis
ATP s y nthes is in c hloroplas ts is v ery s imilar to that in mitoc hondria: Elec tron trans port is c oupled to the formation of a proton (H+) gradient ac ros s a
membrane. The energy in this proton gradient is then us ed to power ATP s y nthes is .
Two ty pes of proc es s es that c ontribute to the formation of the proton gradient are:
proc es s es that releas e H+ from c ompounds that c ontain hy drogen, and
proc es s es that trans port H+ ac ros s the thy lak oid membrane.
Drag the labels to the appropriate locations on the diagram of the thylakoid m em brane. Use only the blue labels for the blue targets, and
only the pink labels for the pink targets.
Note: One blue target and one pink target should be left em pty. Hin t 1. How does the oxidation of water by PS II contribute to the proton gradient?
In Photos y s tem II (PS II), light energy is us ed to produc e an elec tron ac c eptor that is s trong enough to ox idiz e water.
How does the oxidation of water contribute to the proton gradient across the thylakoid m em brane?
Water molec ules pic k up protons from the s troma and trans port them to the thy lak oid s pac e, where the water is ox idiz ed.
Ox y gen molec u...
View Full Document
- Spring '14