Kinetics of the oxyhydrogen reaction in the presence and absence of carbon dioxide in Scenedesmus obliquus

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.67.1.129· OSTI ID:6601223

Erbes, D L; Gibbs, M

The oxyhydrogen reaction in the presence and absence of CO/sub 2/ was studied in H/sub 2/-adapted Scenedesmus obliquus by monitoring the initial rates of H/sub 2/, O/sub 2/, and /sup 14/CO/sub 2/ uptake and the effect of inhibitors on these rates with gas-sensing electrodes and isotopic techniques. In the presence of 0.02 atmosphere O/sub 2/, the pH/sub 2/ was varied from 0 to 1 atmosphere. Whereas the rate of O/sub 2/ uptake increased by only 30%, the rate of H/sub 2/ uptake increased severalfold over the range of pH/sub 2/ values. At 0.1 atmosphere H/sub 2/ and 0.02 atmosphere O/sub 2/, rates for H/sub 2/ and O/sub 2/ uptake were between 15 and 25 micromoles per milligram chlorophyll per hour. As the pH/sub 2/ was changed from 0 to 1 atmosphere, the quotient H/sub 2/:O/sub 2/ changed from 0 to roughly 2. This change may reflect the competition between H/sub 2/ and the endogenous respiratory electron donors. Respiration in the presence of glucose and acetate was also competitive with H/sub 2/ uptake. KCN inhibited equally respiration (O/sub 2/ uptake in the absence of H/sub 2/) and the oxyhydrogen reaction in the presence and absence of CO/sub 2/. The uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone accelerated the rate of respiration and the oxyhydrogen reaction to a similar extent. It was concluded that the oxyhydrogen reaction both in the presence and absence of CO/sub 2/ has properties in common with components of respiration and photosynthesis. Participation of these two processes in the oxyhydrogen reaction would require a closely linked shuttle between mitochondrion and chloroplast.

• Research Organization: Brandeis Univ., Waltham, MA
• DOE Contract Number: AC02-76ER03231
• OSTI ID: 6601223
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 67:1; ISSN PLPHA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ACETATES
AERIAL MONITORING
ALDEHYDES
ALGAE
BIOASSAY
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLOROPHYLL
CHLOROPLASTS
ELEMENTS
GLUCOSE
GROWTH
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HEXOSES
HYDROGEN
KINETICS
LABELLED COMPOUNDS
METABOLISM
MITOCHONDRIA
MONITORING
MONOSACCHARIDES
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYSIOLOGY
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
REACTION KINETICS
RESPIRATION
SACCHARIDES
SUBSTRATES
SYNTHESIS
TIME DEPENDENCE
UPTAKE