Hirst grew up in Lepton, a village near Huddersfield, West Yorkshire, and attended King James's School and Greenhead College, Huddersfield.^[3] She studied for an M.A. in chemistry at St John's College, Oxford,^[2] and then was awarded a Doctor of Philosophy degree at Lincoln College, Oxford, in 1997, for research supervised by Fraser Armstrong on electron transport in redox enzymes.^[1]

Following her D.Phil., Hirst held a fellowship at the Scripps Research Institute in California, before moving to Cambridge.^[4]

As of 2023^[update] Hirst is a professorial fellow and Director of Studies in Natural Sciences Chemistry at Corpus Christi College, Cambridge,^[4] and since 2020 has been director of the MRC Mitochondrial Biology Unit having previously been its assistant director (2011-2014) and deputy director (2014-2020). Her main research interest is mitochondrial complex I.^[2]

Hirst has been published in 2018 on Open questions: respiratory chain supercomplexes – why are they there and what do they do?^[5] and working with Justin Fedor, published research on mitochondrial supercomplexes in Cell Metabolism.^[6] Recent research in her team includes a study, published in May 2020 by the American Chemical Society Synthetic Biology on 'Adenosine triphosphate (ATP), the cellular energy currency, is essential for life. The ability to provide a constant supply of ATP is therefore crucial for the construction of artificial cells in synthetic biology' which has developed a 'minimal system for cellular respiration and energy regeneration'.^[7]

Early in her career, Hirst was awarded EMBO Young Investigator Award (2001) and Young Investigator Award from the Royal Society of Chemistry Inorganic Biochemistry Discussion Group (2006).^[8]

Hirst was elected a Fellow of the Royal Society (FRS) in 2018.^[9] She was awarded an Interdisciplinary Prize of the Royal Society of Chemistry in the same year.^[10] In 2019, Hirst was elected Fellow of the Academy of Medical Sciences^[11] with the citation:

Judy Hirst, Professor of Biological Chemistry at the MRC Mitochondrial Biology Unit, Cambridge, has had a definitive hand in every advance towards defining the highly complex mechanism of complex I catalysis, and has developed new physical and biochemical methods to address the elusive coupling mechanism between the redox reaction and proton translocation. She established the mechanism of complex I inhibition by the anti-diabetic drug metformin, and has used kinetic and thermodynamic strategies to define how superoxide production by complex I, responds to the intramitochondrial NADH/NAD+ ratio to directly link two pathological effects of complex I dysfunction. This seminal work has brought understanding that is fundamental to critical issues of health and disease on a global stage.^[12]

Hirst was awarded Keilin Memorial Lecture and Medal in 2020 for research which:

has made pivotal contributions to understanding energy conversion in complex redox enzymes: how they capture the energy released by a redox reaction to power proton translocation across a membrane, or catalyse the interconversion of chemical bond energy and electrical potential. She is known particularly for her work on mammalian respiratory complex I (NADH: ubiquinone oxidoreductase), an energy-transducing, mitochondrial redox enzyme of fundamental and medical importance, and for solving its structure by electron cryomicroscopy.^[13][14]

• Official website
• Judy Hirst publications indexed by Google Scholar