welcome biologists to this session where we're going to take a look at the importance of photosynthetic pigments in photosynthesis the second part here thin layer chromatography we'll do in a second video so from the previous video we should remember that the chloroplast has a lot of thylakoid membranes in there and that creates a large surface area for these photosynthetic pigments to be attached to so these photo synthetic pigments they are arranged in structures called photosystems now as we go through photosynthesis you'll learn that there are two photo systems that we need to be aware of photosystem two and one which are involved within the light dependent reaction now within these photo systems we have pigments and these pigments are arranged in a funnel shape called the antenna complex which you can see within this image here now this is all to do with absorbing different wavelengths of light and the primary pigment which is here within the reaction center is chlorophyll a which we do need to be aware of so anything in a red box is the important stuff you need to know from the mark schemes so as well as the chlorophyll a which is the primary pigment within the reaction center we have other pigments involved here and the whole idea behind having these other pigments is so that they can absorb different wavelengths of light from each other um and this allows more energy to be absorbed from the light to be passed on to electrons now you do need to be aware of some of the names of these different pigments so the different pigments involved here are called accessory pigments and the examples you need to be aware of are carcinoids chlorophyll b and xanthrophill and chloroph and beta-carotene as well so xanthophyll and beta-carotene are examples of the carotenoids but you do get marks for either of them or any of them so just make sure you know some of those examples of accessory pigments so the way that these work is first of all these different pigments absorb different wavelengths of light or photons of light it's really important here that you don't say they just absorb light you have to say different wavelengths or photons of light and so these accessory pigments so they could be carotenoids which could be xanthophyll or beta-carotene or they could be um chlorophyll b they pass on energy into that primary pigment at the bottom here is chlorophyll a and the range of accessory pigments that the the photosystem has allows a range of wavelengths to be absorbed now the primary pigment which is chlorophyll-a and this becomes excited by this energy it is that has been passed to it and this energy that chlorophyll a has it will pass it onto electrons and it will lose those electrons the electrons transport chain and those electrons become excited to a higher energy level and we're going to learn about how they're used a bit later on when we learn about the light dependent reaction in a little bit more detail so for now all we need to know is that those excited electrons will be used in the light dependent reaction which you'll look at in the next couple of videos so just to remind you this is um the different wavelengths of light that we have within the visible light spectrum and i have seen it in a couple of times within suggest questions uh but these shorter wavelengths of light can penetrate into deeper water than the ocean so for example those um plants that will exist at those deeper waters will have different pigments of those that are closer to the surface because they will absorb different wavelengths of light so just familiarize yourself with that and be aware that that could come up on suggest questions but that is everything we need to know on photosynthetic pigments guys please like and share the video and good luck with your exams