In the paper, researchers from Sogang University in South Korea and the Harbin Institute of Technology in China look at advances in efforts to develop artificial mitochondria and chloroplasts and the problems that still need to be resolved. Chloroplasts and mitochondria handle energy production in the natural world and, as such, researchers have looked to them for answers about how to power artificial cells.

"If scientists can create artificial mitochondria and chloroplasts, we could potentially develop synthetic cells that can generate energy and synthesize molecules autonomously," Sogang University's Kwanwoo Shin, one of the authors of the paper, said in a statement.

Efforts to realize that vision have been hindered by the complexity of the organelles. Mitochondria are among the most complex intracellular components to replicate artificially but in recent years researchers have made some progress.

The paper describes the components required to construct synthetic mitochondria and chloroplasts. In the view of the authors, proteins are the critical component for molecular rotary machinery, proton transport, and the production of adenosine triphosphate (ATP), the molecule that cells use to store and transfer energy.

Researchers have replicated some components that organelles use to make energy. The authors of the paper identify investigations of "the intermediate operations involved in the complex energy-generating process" as among the most promising areas of research, explaining how scientists have connected the sequence of proteins and enzymes to improve energy efficiency.

Significant challenges remain unresolved though. According to the paper, enabling self-adaptation in changing environments to maintain a stable supply of ATP is still a barrier to the reconstruction of the energy-production capabilities of organelles. The authors expect future studies to focus on the limitation to make synthetic cells that are self-sustaining.

As researchers tackle the challenge, the authors believe it will be important to create artificial cells with biologically realistic energy-generation methods that mimic natural processes, explaining that replicating the entire cell could lead to future biomaterials and shed light on the origin of life and the origin of cells.

The authors of the review have contributed previously to the advance of the field; for example, in a Nature Biotechnology study they described the use of photosynthetic artificial organelles to sustain and control ATP-dependent reactions.