ON BIOLOGICAL OXIDATIONS AS FUNCTION OF TEMPERATURE.

Area of Science:

• Biochemistry
• Physiology
• Enzymology

Background:

• Biological respiration involves complex catalyzed reactions.
• Understanding thermal sensitivity is crucial for elucidating reaction mechanisms.
• Iron and hydroxyl ions are implicated as catalysts in biological processes.

Purpose of the Study:

• To calculate critical thermal increments for respiratory processes in diverse organisms.
• To investigate the role of specific ions and catalysts in biological reactions.
• To explore the potential of thermal increment analysis for identifying controlling reactions in living matter.

Main Methods:

• Calculation of critical thermal increments (Arrhenius activation energy) for oxygen consumption and carbon dioxide production.
• Analysis of bacterial methylene blue reduction and iron oxidation.
• Comparison of thermal increments across different biological systems and chemical reactions.

Main Results:

• Identified two to three types of critical thermal increments (micro values: 11,500, 16,100, 16,700) for respiration.
• Observed a micro value of 16,700 for bacterial succinic acid dehydrogenation and 16,140 for ferrous iron oxidation.
• Found consistency between respiration thermal increments and those of catalyzed reactions, particularly those involving iron.

Conclusions:

• The critical thermal increments suggest a common dehydrogenation mechanism in biological respiration.
• Iron likely acts as a catalyst in many respiratory processes, influencing thermal increment values.
• Thermal increment analysis offers a promising method for identifying rate-limiting reactions in undisturbed biological systems.