Donald Granger

Bio: Donald Granger is an academic researcher. The author has contributed to research in topics: Polarography. The author has an hindex of 1, co-authored 1 publications receiving 744 citations.

[7] Mitochondrial respiratory control and the polarographic measurement of ADP : O ratios

Abstract: Publisher Summary This chapter discusses the mitochondrial respiratory control and the polarographic measurement of ADP : O ratios. The polarographic oxygen electrode technique is used for measuring rapid changes in the rate of oxygen utilization by cellular and subcellular systems. Although the polarographic method measures changes in oxygen concentration of photosynthetic systems, yeast cells, and nerve, but the oxygen electrode technique is applied to a study the mitochondrial respiration and oxidative phosphorytation. The principle of the oxygen electrode has been summarized, and the design of the vibrating oxygen electrode for use with speetrophotometric studies is illustrated. The oxygen electrode apparatus can be calibrated in a number of ways. A more accurate calibration of oxygen content can be obtained by gas equilibration with various nitrogen-oxygen mixtures. When tightly coupled mitochondria are suspended in an isotonic buffer, a slow rate of oxygen uptake is measured in the presence of substrate and absence of ADP. Addition of ADP causes an immediate increase in the rate of oxygen utilization. The concentration of oxygen utilized is proportional to the amount of ADP phosphorylated to ATP. The type of oxygen electrode tracings is presented from which an ADP : O ratio (equivalent to a P : O ratio) can be directly calculated.

Hydrogen Sensors - A review

Abstract: Hydrogen sensors are of increasing importance in connection with the development and expanded use of hydrogen gas as an energy carrier and as a chemical reactant. There are an immense number of sensors reported in the literature for hydrogen detection and in this work these sensors are classified into eight different operating principles. Characteristic performance parameters of these sensor types, such as measuring range, sensitivity, selectivity and response time are reviewed and the latest technology developments are reported. Testing and validation of sensor performance are described in relation to standardisation and use in potentially explosive atmospheres so as to identify the requirements on hydrogen sensors for practical applications.

Microelectrodes: Their Use in Microbial Ecology

Abstract: Among the fundamental goals of microbial ecology is the development of methods that will enable the identification and counting of the important microorganisms in nature, the determination of their physical and chemical microenvironment, and the analysis of their metabolic processes and interactions. Due to the small size of the organisms, much effort has been devoted to the development of high-resolution techniques for the observation and understanding of the world of bacteria on a microscale. Scanning and transmission electron microscopy and fluorescent staining, immunofluorescence and other techniques for light microscopy have been the most successful in terms of reaching a high spatial resolution. With respect to our understanding of the microbial microenvironments and of the nature of the microorganisms that carry out the measured metabolic activities, there is still a long way to go. Most chemical and radiotracer techniques in use today operate on a centimeter or at best on a millimeter scale and in most cases their results cannot be directly related to the relevant microorganisms. One notable exception to this is the combined use of autoradiography and fluorescence microscopy on microbial communities.