How is earth's early land environment different than today's land environment?

Because Earth Tectonic plates where not shifted apart back then we called it Pangea

Earth's early land has many poisonous gas and the crust is not fully developed. Volcanoes erupt most of the time. Some single cell organisms began to form but it will take centuries until multicellular organisms and plants to form. Water isn't present during Earth's early form

Biochemistry, it deals with the chemical constitution, the breakdown and the synthesis of plant and animal products.