Inpsiithefirs tphotos y s teminthes equenc ep680is ox

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ore beginning this tutorial, watc h the Light Reac tions animation. Pay partic ular attention to the s teps where light is inv olv ed, the pattern of elec tron flow, and the c oupling of elec tron trans port to the formation of a proton se ssion.ma ste r ingbiology.c om/myc t/a ssignme ntPr intVie w? a ssignme ntI D= 2242937 14/41 13- 10- 13 Cha pte r 10 gradient and ATP s y nthes is . Part A ­ F unctions of the photosystems The light reac tions require the c ooperation of two photos y s tems to power linear elec tron flow from water to NADP+. Drag each item into the appropriate bin depending on whether the process is associated with Photosystem II (PS II) only, Photosystem I (PS I) only, or both PS II and PS I. Note that “ electron transport chain” here refers to the electron transport chain between the two photosystem s, not the one that functions after PS I. Hin t 1. Roles of chlorophylls in the light reactions Chlorophy lls play two roles in the light reac tions : abs orption of light and reduc tion of a primary elec tron ac c eptor. Cons ider where the c hlorophy lls are loc ated among the v arious c omponents of the light reac tions . Hin t 2. What redox reactions occur in Photosystem II? In Photos y s tem II (PS II), the ex c ited s tate of P680 c hlorophy ll trans fers an elec tron to the PS II primary elec tron ac c eptor. The res ulting pos itiv ely c harged P680+ is the s tronges t k nown biologic al ox idant (elec tron ac c eptor). What is the role of P680+ in the light reactions? ANSWER: ox idation of the elec tron trans port c hain between the photos y s tems reduc tion of the elec tron trans port c hain between the photos y s tems ox idation of water to O2 reduc tion of NADP+ to NADPH Hin t 3. What redox reactions occur in Photosystem I? In Photos y s tem I (PS I), the ex c ited s tate of P700 c hlorophy ll trans fers an elec tron to the PS I primary elec tron ac c eptor. The res ulting reduc ed primary elec tron ac c eptor in PS I is one of the s tronges t k nown biologic al reduc t...
View Full Document

This document was uploaded on 02/17/2014 for the course BIOCHEMIST 2550 at Ohio State.

Ask a homework question - tutors are online