Robert John Porra (7.8.1931–16.5.2019) is probably best known for his substantial practical contributions to plant physiology and photosynthesis by addressing the problems of both the accurate spectroscopic estimation and the extractability of chlorophylls in many organisms. Physiological data and global productivity estimates, in particular of marine primary productivity, are often quoted on a chlorophyll basis. He also made his impact by work on all stages of tetrapyrrole biosynthesis: he proved the C₅ pathway to chlorophylls, detected an alternative route to protoporphyrin in anaerobes and the different origin of the oxygen atoms in anaerobes and aerobes. A brief review of his work is supplemented by personal memories of the authors.

Robert John Porra (7.8.1931–16.5.2019) 最著名的可能是他通过解决许多生物体中叶绿素的准确光谱估计和可提取性问题，对植物生理学和光合作用做出的重大实际贡献。生理数据和全球生产力估计，特别是海洋初级生产力，通常以叶绿素为基础引用。他还通过对四吡咯生物合成各个阶段的工作产生了影响：他证明了叶绿素的 C ₅途径，检测了厌氧菌中原卟啉的替代途径以及厌氧菌和需氧菌中氧原子的不同来源。作者的个人记忆补充了对他的工作的简要回顾。