BIOL1007 Lecture Notes - Lecture 8: Nicotinamide Adenine Dinucleotide Phosphate, Ferredoxin, Plastocyanin
19 May 2018
School
Department
Course
Professor
Describe the major evolutionary events to maximise light capture by
plants
Great
oxidati
on
event
-
2.5 bill years ago
○
Earliest ancestors of modern plants
○
Bacteria produced free oxygen in the atmosphere
○
Green bacteria have chloroplasts, with light harvesting complexes
○
ENDOSYMBIOSIS
First
land
plants
about
450 mill
years
ago
Oxygen reacted in upper atmosphere to produce ozone - UV protection
○
Plants could start colonising the land
○
400 mill
years
ago
Plants wide-spread on land
-
Plants pumped O2 into atmosphere and dragged CO2 out of atmosphere
-
CO2 conc in atm is low for the first time
-
MAJOR PROBLEM for plants
-
Biochemistry is aqueous, but need to increase CO2 diffusion
-
L8 - photosynthesis I
Friday, 29 September 2017
7:48 PM
Mod 2 Energy Systems and Cells Page 1
Document Summary
Describe the major evolutionary events to maximise light capture by plants. Green bacteria have chloroplasts, with light harvesting complexes. Oxygen reacted in upper atmosphere to produce ozone - uv protection. Plants pumped o2 into atmosphere and dragged co2 out of atmosphere. Co2 conc in atm is low for the first time. Biochemistry is aqueous, but need to increase co2 diffusion. Mod 2 energy systems and cells page 1. Take photo using scanningelectron microscope -> builds 3d image of leaf. Describe, in overview, the conversion of radiant energy into chemical energy. Explain the overall organisation of the light reactions in photosystems i and ii. Electron is activated -> splitting of water into oxygen and hydrogen. Electron moves up chain to plastoquinone -> pq moves h from stroma (outside) into lumen (interior) Hands electron onto cytochrome -> moves electron across. Ps i activated by light of a different wavelength. Electron moves to fnr which reduces nadp to nadph.
