Dipeptide coacervates are artificial membraneless organelles that mimic cellular functions and enable non-biological processes in cells. These coacervates, formed through liquid-liquid phase separation, exhibit enhanced stability, biocompatibility, and a hydrophobic microenvironment. This hydrophobic nature allows the encapsulation of hydrophobic species, including transition metal-based catalysts, which enhances their efficiency in aqueous environments. Dipeptide coacervates carrying a metal-based catalyst are incorporated into cells and trigger internal non-biological chemical reactions. The development of coacervates with a hydrophobic microenvironment opens new avenues in biomimetic materials for applications in catalysis and synthetic biology. Artificial materials that mimic biological cells allow the recreation of life-like behavior, including molecular localization and regulation of complex chemical reactions. Coacervate droplets, similar to membrane-free cellular organelles, have gained attention due to their biophysical and functional properties. Unlike vesicles or capsules, coacervates are spontaneously formed through liquid-liquid phase separation, resulting in condensed liquid droplets that provide a distinct microenvironment for sequestering and concentrating biological molecules. Peptide-based coacervates offer advantages over traditional polyelectrolyte-based coacervates, including better biocompatibility and the ability to form microenvironments through weak interactions like π-π, cation-π, and hydrogen bonding. These interactions are similar to those in biomolecular condensates, providing insights into the mechanisms of LLPS in cells. Peptide coacervates can be designed with minimal sequence, allowing for customizable microenvironments. Dipeptide coacervates can encapsulate hydrophilic enzymes and hydrophobic active species, acting as reaction centers that enhance the catalytic activity of hydrophobic catalysts in aqueous environments. Transition metal catalysts (TMCs) are important for organic synthesis and synthetic biology. However, their limited water solubility and low biocompatibility often require rigid nanoscale supports. Dipeptide coacervates can encapsulate TMCs, enabling their use as artificial organelles in cells. This allows for the intracellular generation of active species through bioorthogonal catalysis. The design and construction of dipeptide coacervates enable the creation of artificial membraneless organelles with biomimetic properties and bioorthogonal catalytic activity. These coacervates can encapsulate hydrophilic enzymes and hydrophobic species, acting as reaction centers that enhance the catalytic activity of hydrophobic catalysts in aqueous environments. Dipeptide coacervates containing TMCs were dimerized to form colloidally stable artificial organelles that were internalized by living cells. The functionality of the internalized organelles was demonstrated by the intracellular production of an active fluorophore via a ruthenium complex-mediated bioorthogonal catalDipeptide coacervates are artificial membraneless organelles that mimic cellular functions and enable non-biological processes in cells. These coacervates, formed through liquid-liquid phase separation, exhibit enhanced stability, biocompatibility, and a hydrophobic microenvironment. This hydrophobic nature allows the encapsulation of hydrophobic species, including transition metal-based catalysts, which enhances their efficiency in aqueous environments. Dipeptide coacervates carrying a metal-based catalyst are incorporated into cells and trigger internal non-biological chemical reactions. The development of coacervates with a hydrophobic microenvironment opens new avenues in biomimetic materials for applications in catalysis and synthetic biology. Artificial materials that mimic biological cells allow the recreation of life-like behavior, including molecular localization and regulation of complex chemical reactions. Coacervate droplets, similar to membrane-free cellular organelles, have gained attention due to their biophysical and functional properties. Unlike vesicles or capsules, coacervates are spontaneously formed through liquid-liquid phase separation, resulting in condensed liquid droplets that provide a distinct microenvironment for sequestering and concentrating biological molecules. Peptide-based coacervates offer advantages over traditional polyelectrolyte-based coacervates, including better biocompatibility and the ability to form microenvironments through weak interactions like π-π, cation-π, and hydrogen bonding. These interactions are similar to those in biomolecular condensates, providing insights into the mechanisms of LLPS in cells. Peptide coacervates can be designed with minimal sequence, allowing for customizable microenvironments. Dipeptide coacervates can encapsulate hydrophilic enzymes and hydrophobic active species, acting as reaction centers that enhance the catalytic activity of hydrophobic catalysts in aqueous environments. Transition metal catalysts (TMCs) are important for organic synthesis and synthetic biology. However, their limited water solubility and low biocompatibility often require rigid nanoscale supports. Dipeptide coacervates can encapsulate TMCs, enabling their use as artificial organelles in cells. This allows for the intracellular generation of active species through bioorthogonal catalysis. The design and construction of dipeptide coacervates enable the creation of artificial membraneless organelles with biomimetic properties and bioorthogonal catalytic activity. These coacervates can encapsulate hydrophilic enzymes and hydrophobic species, acting as reaction centers that enhance the catalytic activity of hydrophobic catalysts in aqueous environments. Dipeptide coacervates containing TMCs were dimerized to form colloidally stable artificial organelles that were internalized by living cells. The functionality of the internalized organelles was demonstrated by the intracellular production of an active fluorophore via a ruthenium complex-mediated bioorthogonal catal