This IBDP Biology blog post will look into an introduction of light dependent reaction and also the summary of the process, let's go!
Light Dependent Reactions
Conversion of light energy into a flow of excited electrons
The following processes take place:
- Photoactivation
- Photolysis
- Electron Transport Chain
- Chemiosmosis
- ATP synthesis
- NADP reduction
Two types photosystems are embedded in the Tylakoid membrane. Photosystem i and Photosystem 2. The difference between the two photosystems:
- Photosystem i is sesitive to light wavelengths of 700 nm
- Phtosystem ii is sesitive to light wavelengths of 680 nm
Photosystem: Clusters of hundreds of photosynthetic pigments that collect light energy (including wavelengths) and pass it to Chlorophyll at the reaction centre
Reaction Centre: A central Chlorophyll molecule
Summary of LDR
- Chlorophyll is part of a group of pigment molecules in photosytems
- Pigments in photosystems (chlorophyll) absorb photons causing electrons within the pigment to be raised to a higher energy level/become excited
- Excited electons are passed from pigment to pigment till the reach Chlorophll A in the reaction centre of the photosystem
- The electrons are then passed to electron acceptors in the Tylakoid membrane
That's it for part 1!
References:
https://www.google.com/url?sa=i&url=http%3A%2F%2Fib.bioninja.com.au%2Fhigher-level%2Ftopic-8-metabolism-cell%2Funtitled-2%2Flight-dependent-reactions.html&psig=AOvVaw1o4KWCOPmK9P_XHYJHQOuz&ust=1627831549486000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCMDd0pzPjfICFQAAAAAdAAAAABAI
Drafted by Venetia (Biology)