Speaker: Professor Vic Arcus

Biochemistry & Molecular Biology

University of Waikato

Enzymes are extraordinary catalysts that enable life to occupy nearly every available niche on our planet. These large, yet delicate, molecules show unusual responses to changes in temperature and this has a significant impact on how biological systems respond. While developing a theoretical description for enzymes (at the molecular scale), we realised that trends in the temperature dependence of biological rates at increasing levels of complexity (e.g. soil respiration and photosynthesis) could be similarly quantified. Our hypothesis is that the signature of enzyme temperature dependence can be found in complex processes such as microbial growth rates, plant and soil respiration, photosynthesis and, ultimately, landscape carbon sequestration. We have now shown that our theory of biological rates describes global photosynthesis and respiration enabling predictions about the response of the terrestrial biosphere to a warming world.