Biological nano- and micromachines; perform transport guarantying functionality of living cells. Thermal fluctuations is the major source of energy for these machines. They transport biological materials and ions, build proteins, attain motility of the cell, etc. Fluctuation driven transport can be studied applying the Brownian ratchet principle, and this concept provides the understanding of how electrochemical energy converted into mechanical energy. The importance of Brownian motion is its versatility in explaining a wide range of biological processes. This paper reports entropy analysis, model developments and analysis of nanobiomotors. This analysis of Brownian motor may result in understanding the motion, energy conversion, energy transfer, as well as other mechanisms and processes at the molecular level specifically examining nano- and micromachines.