BIOL10004 Chapter Notes - Chapter 6: Bacteriochlorophyll, Manganese, Ribulose

96 views11 pages
29 Jun 2018
Department
Course
Professor
Harvesting Light Energy: Photosynthesis
Photosynthesis is the process which solar energy harvested and stored in chemical bonds of
ATP and carbohydrates, made from CO2 and H2O
Chlorophyll is the light absorbing pigment in photosynthetic organisms
Eukaryotes
oChlorophyll associated with thylakoid membranes of chloroplast
Chloroplasts have wide variety of sizes and shapes,
Overall Process of photosynthesis involves chemical reactions
In Eukaryotes, 3 essential chemical processes in photosynthesis
1. Absorption of energy from sunlight by pigments-light depending reactions:
Harvesting of light energy through Photosystem 1 and Photosystem 2
Consists of protein molecules in pigments held in special arrangements
Photosystems embedded in thylakoid membranes of chloroplasts
Light energy absorbed by pigment molecules
Transferred to special part of photosystem , the reaction centre
Electrons here energise and removed to be used in chain reactions
Energy stored in molecules of ATP and NADPH
2. Reactivation of reaction centres:
Reaction centres reactivate
Replaces electrons removed follow light energy absorption
Water acts as source of electrons
Oxygen produce as by-product
3. Carbon fixation to produce carbohydrates in 'dark reactions'
Reactions are light independent
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 11 pages and 3 million more documents.

Already have an account? Log in
Uses energy from ATP and NADPH
Synthesise sucrose and starch
Reactions function in darkness and in light
Depends on ATP and NADPH has been generated in light reactions
Light energy
Light is form of EMR
oHas wave and particle properties
oWave nature described in terms of wavelength/frequency
oWhen interacting with matter, light = photons (discrete packages of energy)
Photos have different amounts of energy
Inversely proportional to wavelength of photo
Blue photos wavelength = 400nm, more energy than red photos = 700nm
Sunlight is mixture of photons with range of energy levels
oSome are perceived by eyes in visible range
oObject that is red, absorbs all other spectrums and reflects red
Light used in photosynthesis falls within visible spectrum
Below visible spectrum, photons have very short wavelengths
Above visible spectrum, photons have very long wavelengths
Pigments: molecules that absorb light
Pigments are coloured molecules
oSeen as coloured because photos with particular wavelengths are absorbed, others
reflected
oChlorophyll is green because absorbs red and blue photons
Reflects green photons
Pigment is characterised by pattern of absorption of photos - Absorption Spectrum
oAbsorption spectrum of chlorophyll similar to wavelengths of light that activate
photosynthesis
Action Spectrum
Chlorophyll is main pigment involved in photosynthesis
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 11 pages and 3 million more documents.

Already have an account? Log in
Chlorophyll absorbs light by process of excitation
oCentral metal atom (magnesium)
oSurrounded by alternating single/double bonds
oForms a Porphyrin Ring
Photons absorbed by pigment
Electrons in magnesium atom excited
Energy funnelled off through the bonds of the porphyrin ring
oChlorophyll a is principal photosynthetic pigment
Found in cyanobacteria, algae and plants
oPhotosynthetic bacteria
Pigment called Bacteriochlorophyll is found
oGreen algae and plants
Also contain chlorophyll b
Slightly different absorption spectrum from chlorophyll a
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 11 pages and 3 million more documents.

Already have an account? Log in

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related Documents

Related Questions