Throughout the ages architects have attempted to capture the essence of living systems as design inspiration. However, practitioners of the built environment have had to deal with a fundamental split between the artificial urban landscape and nature owing to a technological 'gap' that means architects have been unable to make effective use of biological systems in urban environments. Protocell Architecture is an edition of AD that shows for the first time that contemporary architects can create and construct architectures that are bottom up, synthetically biological, green and have no recourse to shallow bio-mimicry. In the next few decades, synthetic biology is set to have as much, if not more, impact on architecture as cyberspace and the digital. The key to these amazing architectural innovations is the Protocell.