Cells are the basic units of life that constitute every living organism. They vary largely in size, organisation and appearance from bacteria, through huge plant cells to eukaryotes. However, they all are very complex systems that have evolved to survive and reproduce, supported by intricate mechanisms. The discovery of DNA as the carrier of genetic information, and understanding how genetic information is translated into proteins revolutionised biology and led to a new discipline: molecular biology. The concepts and methods of molecular biology enable us to catch a glimpse of the intimate inner life of cells. In this module, we are going to look at cells at the molecular level, covering topics such as cellular organisation, energetics, membranes, transport systems, and intra- and intercellular communication. A strong emphasis is placed on learning about the scope and applicability of experimental techniques in molecular biology. At the end of the module, students should be able to select from molecular experimental techniques and apply concepts in order to solve cell biological questions.