Photochemistry and enzymology of photosynthesis. Progress report, November 1, 1978-May 31, 1981

Technical Report · Fri May 01 04:00:00 EDT 1981

DOI:https://doi.org/10.2172/6232594· OSTI ID:6232594

Radmer, R.; Golbeck, J.; Velthuys, B.

Three different aspects of photosynthesis are being investigated. Three different technical approaches are being used (i.e., mass spectrometry; biochemical techniques; and a combination of polarographic, spectroscopic, and fluorescence techniques). In the first group of experiments, a specially designed mass spectrometer system was used to monitor the gas exchange in chloroplasts in response to single short flashes of light. Several gases and their isotopes (e.g., N/sub 2/, /sup 15/N/sub 2/, /sup 18/O/sub 2/, etc.) were monitored to study photosystem II reactions in chloroplasts, particularly those reactions that use donors other than H/sub 2/ /sup 16/O (and evolve products other than /sup 16/O/sub 2/). Our goal was to obtain a better understanding of the O/sub 2/-evolving system. The second topic studied was the role of copper in photosynthesis. Biochemical techniques were applied to investigating the role of nonplastocyanin copper in photosystem II- and photosystem I-mediated O/sub 2/ uptake via polyphenol oxidase. The third area of study was light harvesting and electron transport in C/sub 4/ plants. Many aspects of carbon flow in C/sub 4/ plants seem to be well understood; however, the distribution of photons and the flow of electrons in the two tissues of the leaves of C/sub 4/ plants remain enigmatic. We used polarographic, spectroscopic, and fluorescence techniques to gain an understanding of these processes.

• Research Organization: Martin Marietta Labs., Baltimore, MD (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76ER03326
• OSTI ID: 6232594
• Report Number(s): DOE/ER/03326-101; ON: DE81025547
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHLOROPLASTS
COPPER
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENZYMES
FERMIONS
KINETICS
LEPTONS
MASS SPECTROSCOPY
MASS TRANSFER
METALS
NITROGEN
NONMETALS
OXIDOREDUCTASES
OXYGEN
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
REACTION KINETICS
RESEARCH PROGRAMS
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENTS