scholarly journals Action Spectra of O2 Evolution by Chloroplasts with & without Added Substrate, for Regeneration of O2 Evolving Ability by Far-red, & for O2 Uptake

1963 ◽  
Vol 38 (3) ◽  
pp. 323-332 ◽  
Author(s):  
D. C. Fork
Keyword(s):  
O2 Evolution ◽  
O2 Uptake ◽  
Action Spectra

Photosynthetic Oxygen Exchange in Attached Leaves of C4 Monocotyledons

1982 ◽  
Vol 9 (5) ◽  
pp. 553 ◽  
Author(s):  
RT Furbank ◽  
MR Badger
Keyword(s):  
Malic Enzyme ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Co2 Concentration ◽  
O2 Evolution ◽  
Co2 Uptake ◽  
O2 Uptake ◽  
Co2 Compensation Point ◽  
Uptake Rates ◽  
Photosynthetic O2 Evolution ◽  
Photosynthetic Oxygen

Photosynthetic O2 evolution, O2 uptake and CO2 uptake by intact leaves from plants of the three C4 decarboxylation types were examined using mass-spectrometric gas-exchange and stable isotope techniques. All species showed a relative insensitivity of O2 uptake to CO2 concentration. The uptake rates observed were between 0.2 and 1 nmol O2 cm-2 S-1 at the CO2 compensation point. At ambient external CO2, NADP-malic enzyme type species showed the lowest average O2 uptake, phosphoenolpyruvate carboxykinase types the highest values, and NAD-malic enzyme types showed intermediate values for O2 uptake. These results are discussed in relation to the contributions to O2 uptake of ribulosebisphosphate oxygenase and photoreduction of oxygen.

scholarly journals Effect of cobalt on growth, pigments and the photosynthetic electron transport in Monoraphidium minutum and Nitzchia perminuta

2003 ◽  
Vol 15 (3) ◽  
pp. 159-166 ◽  
Author(s):  
M.M. El-Sheekh ◽  
A.H. El-Naggar ◽  
M.E.H. Osman ◽  
E. El-Mazaly
Keyword(s):  
Electron Transport ◽  
Algal Species ◽  
Photosynthetic Electron Transport ◽  
Experimental Period ◽  
Fluorescence Induction ◽  
O2 Evolution ◽  
O2 Uptake ◽  
Acceptor Side ◽  
Low Co2 ◽  
Co2 Concentrations

The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured under different concentrations of Co2+. Growth and pigment content were slightly increased at low concentrations and inhibited by high Co2+ concentrations. The results concerning the effect of different concentrations of Co2+ on photosynthetic O2 evolution showed a reduction in the amount of O2 evolved by each alga in response to increasing Co2+ concentrations. However, an increase in O2 evolution for both M. minutum and N. perminuta was observed at relatively low Co2+ concentrations. Photosynthetic electron transport in M. minutum was more sensitive to Co2+ toxicity than in N. perminuta. On the other hand, the effect of the heavy metal on respiration showed that higher Co2+ concentrations were inhibitory to O2 uptake by the two algal species. Low Co2+ concentrations stimulated O2 uptake by M. minutum throughout the experimental period. However, in N. perminuta, different concentrations of Co2+ led to a reduction of O2 uptake. To localize the action site of Co2+ in the photosynthetic electron transport chain, the fluorescence induction technique was carried out. According to the results obtained, the inhibitory action of Co2+ is located on the acceptor side of PSII for both M. minutum and N. perminuta.

CO-reacting haemoproteins of neutrophils: Evidence for cytochrome b-245 and myeloperoxidase as potential oxidases during the respiratory burst

1987 ◽  
Vol 7 (3) ◽  
pp. 193-199 ◽  
Author(s):  
Steven W. Edwards ◽  
David Lloyd
Keyword(s):  
Cytochrome B ◽  
Respiratory Burst ◽  
Absorption Maximum ◽  
Room Temperature ◽  
Polymorphonuclear Leucocytes ◽  
O2 Uptake ◽  
Difference Spectra ◽  
Action Spectra ◽  
Photochemical Action

Room temperature, CO-difference spectra of intact rat polymorphonuclear leucocytes (neutrophils) revealed the presence of a number of CO-binding haemoproteins. Absorption maxima at 413, 540 and 570 nm were attributed to the CO-complex of cytochrome b-245 whereas an absorption maximum at 595 nm was assigned to the contribution from a myeloperoxidase complex, since an identical absorption maximum was observed in CO-difference spectra of purified myeloperoxidase in the presence of H2O2. Photochemical action spectra for the relief of CO-inhibited O2 uptake revealed contributions from both cytochrome b-245 and myeloperoxidase. The potential of these two O2- and CO-binding haemoproteins to function as oxidases during the respiratory burst is discussed.

O2 transfer kinetics in a whole blood unicellular thin layer

1990 ◽  
Vol 68 (5) ◽  
pp. 1854-1864 ◽  
Author(s):  
E. Heidelberger ◽  
R. B. Reeves
Keyword(s):  
Thin Layer ◽  
Fiber Optics ◽  
Whole Blood ◽  
Gas Flow ◽  
Release Kinetics ◽  
Gas Diffusion ◽  
Attractive Alternative ◽  
Half Time ◽  
O2 Uptake ◽  
Mixing Techniques

A planar monocellular layer of whole blood (WB) sandwiched between two Gore-Tex membranes is used to study O2 uptake and release kinetics at 37 degrees C. Gore-Tex, a highly gas-permeable open mesh of Teflon fibrils (78% porosity, 0.2-microns pore size, 75-microns thick), constrains WB to form a thin film without imposing an appreciable gas diffusion barrier. WB layer thickness, measured by isotope dilution, is 1.7 +/- 0.2 microns. WB films are mounted between fiber optics in a gas flow tube for dual-wavelength (536/558 nm) oxyhemoglobin saturation measurements after a step change in PO2. For isocapnic (6% CO2) step changes in PO2 between 0 and 104 Torr, WB O2 uptake half time is 10.4 +/- 0.9 ms; WB O2 release half time is 20.6 +/- 2.4 ms. Half-time values are half of those previously reported. The thin-layer method reduces erythrocyte diffusion boundary layer error and thereby offers an attractive alternative to classical rapid fluid-mixing techniques.

scholarly journals Correction: A library of action spectra for erythema and pigmentation

2020 ◽  
Vol 19 (12) ◽  
pp. 1790-1791
Author(s):  
Alois W. Schmalwieser ◽  
Silvia Wallisch ◽  
Brian Diffey
Keyword(s):  
Action Spectra

Correction for ‘A library of action spectra for erythema and pigmentation’ by Alois W. Schmalwieser et al., Photochem. Photobiol. Sci., 2012, 11, 251–268, DOI: 10.1039/c1pp05271c.

Sign in / Sign up

Export Citation Format

Share Document