Photosynthesis is a complicated subject! I'm in the process of making half a dozen videos to address it. If you want to see a simple overview of photosynthesis, check out this video:
My latest photosynthesis tutorial covers the light-dependent reactions in some detail. Here it is:
A few apologies and explanations are in order.
You may have noticed that I don't provide balanced chemical equations in this video. That's because I wanted to focus on the different complexes of proteins and pigments, the products they create, and the movement of those products. If I gave the stoichiometry of photosynthesis the attention it deserves, the video would have been too long.
If you're taking biochemistry, AP Biology, or a college-level course on plants, you'll need to know the details of the chemical reactions. I'll have another video for you in the near future.
You'll also notice that I mentioned the Calvin cycle in this video, and that's not a mistake. While the Calvin cycle isn't really a part of the so-called "light-dependent reactions" of photosynthesis, it is still dependent upon the products of these reactions. This is the reason the Calvin cycle is more active in daylight hours, even though it isn't really "light dependent." I want to link the Calvin cycle and the light-dependent reactions, even though they're usually treated separately.
In the next few videos, we'll look at the Calvin cycle in detail. Then we'll take a look at the chemical reactions involved in all the different parts of photosynthesis.