11 research outputs found
Amino acid transport : the special case of a H/L-glutamate cotransport system in Asparagus sprengeri mesophyll cells /
The addition of L-Glutamate (L-GLU) and L-Hethionine
~ulfoximine (L-HSO) to mechanically isolated. photosynthetically
competent, Asparagus sprengeri mesophyll cells
~u~pended in 1mM CaS04 cau~ed an immediate transient
alkalinization of the cell su~pension medium in both the light
and dark. The alkalinization response was specific and
stereospecific as none of the L-isomers of the other 19 protein
amino acids tested or D-GLU gave this response. Uptake of
14C-L-GLU was stimulated by the light. The addition of
non-radioactive L-GLU. or L-GLU analogs together with
14C-L-GLU showed that only L-GLU and L-HSO stimulated
alkalinization whilst inhibiting the uptake of 14C-L-GLU.
Both the L-GLU dependent alkalinization and the upt~ke of
14C-L-GLU were stimulated when the external pH was decreased
from 6.5 to 5.5. Increasing external K+ concentrations
inhibited the uptake of 14C-L-GLU. Fusicoccin (FC)
stimulated uptake. The L-GLU dependent alkalinization re~ponse
exhibited monophasic saturation kinetics while the uptake of
14C-L-GLU exhibited biphasic saturation kinetics. In
addition to a saturable component. the uptake kinetics also
showed a linear component of uptake. Addition of L-GLU and L-MSO
caused internal acidification of the cell as measured by a change
in the distribution of 14C-DMO. There was no change in
K+ efflux when L-GLU was added. A H+ to L-GLUinflux
stoichiometry of 3:1 wa~ mea~ured at an external I.-GLU
concentration of O.5mM and increased with increasing external
13
L-QLU concentration. Metabolism of L-GLU was detected
manometrlcally by observing an increase in COa evolution
upon the addition of L-QLU and by detection of i*C02
evolution upon the addition of »*C-L-GLU. »*C02
evolution was higher in the dark than in the light.
The data are consistent with the operation of a
H+/L-QLO cotransport system. The data also show that
attempts to quantify the stoichlometry of the process were
complicated by the metabolism of L-GLU
Habermas, Same-Sex Marriage and the Problem of Religion in Public Life
This article addresses the debate over religion in the public sphere by analysing the conception of ‘religion’ in the recent work of Habermas, who claims to mediate the divide between those who defend public appeals to religion without restriction and those who place limits on such appeals. I argue that Habermas’ translation requirement and his restriction on religious reasons in the institutional public sphere rest on a conception of religion as essentially apolitical in its origin. This conception, I argue, remains embedded in a standard secularization framework, despite Habermas’ claim to offer a new account of secularization. This approach betrays the complex reality of the political constitution of religion and the religious constitution of politics, as demonstrated by the current debate about marriage rights in the USA. In mischaracterizing the inherently public and political dimensions of religion, Habermas undermines the effectiveness of his normative framework