I'm sure what you mean by structure? I'm going assuming you mean what's within the organelle. I forget a lot of my biology, but I'll try to help since no one else has answered.
As far as chloroplast goes, there is a sub-organelle called a thylakoid. This is where the actual photosynthesis is taking place. Google thylakoid. Other keywords could be the lumen, the area inside the thylakoid; granum, a stack of thylakoids; and chlorophyll, the actually molecules that are absorbing the light. The Calvin cycle sums up the light-independent reactions. I don't think there is a name for the light dependent reactions.
As far as mitochondria go, you need to look into the inner and outer membranes. They play different roles in the process. You also have the mitochondrial matrix, which has other sub parts. I think the inner membrane is actually called the cristae, but don't quote me on that. The major keyword for the reactions in the mitochondria would have to be the Krebs cycle. It sums up the break down of carbohydrates.
Another thing is that some of the fluids have specific names I believe. I can't remember a lot of the stuff, and the finer mechanics off the top of my head.