Metabolic intermediates can also accumulate in the cell and reach concentrations high enough to drive chemical reactions. A typical cell membrane is a lipid bilayer punctuated with proteins and carbohydrates. It seems most likely that life on Mars will be microbial. There has been no evidence of macroscopic life forms, like large animals or plants. Even if multi-cellular life exists microbial life presumably would also be present.
Unicellular microbes are the simplest independent forms of life on Earth.
Many theoretical arguments have been made for the origin of life on Earth. There have also been some seminal experiments. Several different mixtures of gases have been used in experiments like these to simulate the atmosphere of the primitive Earth. Some believe that the atmosphere was controlled by volcanic gas release . The electric discharge from the arc lamp simulates lightening.