Proteins undergo a complex and tightly regulated life cycle. Disturbances in any stage of this cycle can lead to many diseases such as neurodegenerative disorders and cancer. A comprehensive understanding of protein homeostasis is vital for developing targeted therapeutics for such diseases. Chemical ligands can inhibit or modulate various stages of protein life cycles, from synthesis to degradation. However, conventional pharmacology has limitations in terms of spatial and temporal control, due to the inherent challenges with ligand diffusion kinetics. Photopharmacology addresses these constraints by conferring photosensitivity onto compounds, thus allowing precise control via light.Chapter 1 introduces Opto-ANL, a photocaged non-endogenous amino acid, which enables selective labelling of new proteins in specific cell types when paired with a mutant methionyl-tRNA synthetase. With light-dependent activation, Opto-ANL tightly controls the labelling period and enhances efficiency over conventional ANL. Chapter 2 presents a photoswitchable translation inhibitor, termed puroswitch, which places translation under optical control. Puroswitch can be tracked using standard puromycin antibodies, enabling the monitoring of protein synthesis through conventional methods such as western blotting and immunohistochemistry. Chapter 3 describes the synthesis of diazocine and tetra-ortho-chlorinated azobenzene photoswitchable amino acids. These novel amino acids are incorporated into a peptide and can be used as modular units for controlling protein function with light. Chapter 4 details the development of PHOtochemically TArgeting Chimeras (PHOTACs) as a strategic tool for the precise optical degradation of synaptic proteins. CaMKIIα-PHOTAC, a bifunctional molecule, upon light exposure, degrades the protein CaMKIIα, leading to a rapid decrease in synaptic function. This thesis underscores the potential of photopharmacology in providing high-resolution tools for dissecting and controlling the protein life cycle, with broad applications in both basic research and therapeutic development.