Why dont plants photosynthesise in the dark

Plants respire all the time, whether it is dark or light, because their cells need energy to stay alive. But they can only photosynthesize when they have light.

The oxidation of water occurs during photosynthetic electron transport during the light reactions of photosynthesis. In the absence of a source of light energy (dark reactions have no direct requirement for light energy), oxygen is not produced.

you can have just about every answer you can think of

protein makes up the building blocks of organs, muscles, skin, hormones and pretty much everything that matters in your body.

some choices are:

peanut butter

seeds

eggs

yogurt

meats

fish

so pretty much meat, dairy, nuts, and grains.