Lab 14 Flashcards
(16 cards)
Focus lab 14
Use of an oxidizing agent to indirectly monitor the rate of electron transport in photosynthesis in vitro
What does DCPIP do
Redox dye - accepts electron from ferredoxin in place of NADP+ and turns clear when reduced.
Photosystem 1 and 2 general jobs and absorbances
2 splits water absorbs 680, 1 passes electrons to nadp reductase by Fd absorbs 700
What had to be done first lab 14
Warm up light and spec (600 nm absorbance setting)
What is blank
Should be everything but DCPIP, find absorbance of just other stuff to study change in DCPIP conc
Inverse squared law
I1/I2=D2^2/D1^2
Controls lab 14
Light room and dark room -> control for PET in absence of light (baseline) and PET caused by ambient room lighting to allow measurement of only PET from light source
What is purpose of “cocktail” instead of making independent reactions one at a time
Minimize error, control for pipetting error, etc and maintain more consistent ratios between tubes
Overall photosynthesis reaction
What is overall reaction for PET
Where does PET occur
Thylakoid membrane
What is the goal of PET
Electron passed from element to element reducing as it goes, this created proton gradient that fuels later stages (dark reactions)
What are the enzymes of PET
PsII, plastoquionine(pq), cytochrome (cyt), plastocyanin (pc), PSI, ferredoxin (fd), NADP reductase - OEC is oxygen evolving complex (water split)
What is light intensity measured in
Lux
What is point of standard curve of DCPIP
Be able to convert absorbance to concentration of oxDCPIP
Why to convert to molarity
Different specs, different concentrations of DCPIP, different chloroplasts, converting to molarity standardizes to allow comparison between groups
