4 billion years ago the temperature was much higher due to repeated volcanoes and hot gases present in the atmosphere. There weren't any live forms on earth. ... The atmosphere had a different concentration of gases on the earth. There were no life sustaining gases.
The activity of an Enzyme is affected by its environmental
conditions. Changing these alter the rate of reaction caused
by the enzyme. In nature organisms adjust the conditions of their
enzymes to produce an Optimum rate of reaction where necessary
or they may have enzymes which are adapted to function well in
extreme conditions where they live.
You can further understand a text if you ask questions.
