English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A system ofH 3 -amethopterin uptake, physiologically and kinetically resembling active transport, has been described inDiplococcus pneumoniae . Uptake by this system has ap H optimum near 6.0, is temperature-dependent, requires a readily available source of energy, and conforms to Michaelis-Menten kinetics. The system showed aK m of 0.9 × 10−6 m and aV max of 1.9 × 10−13 moles per min per mg (dry weight). Both folate and H2 -folate compete withH 3 -amethopterin for the same system, but to a limited degree. The intracellular concentration ofH 3 -amethopterin accumulated at equilibrium was 1.06 × 10−9 moles/ml or fivefold the external concentration when the latter was limiting, but at least 60-fold the internal concentration attained solely by diffusion in the same time interval at 0 C.

Genetically Alterable Transport of Amethopterin in Diplococcus pneumoniae I. Physiological Properties and Kinetics of the Wild-type System