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Biomedical subjects

R B Park

Publications and source records attributed to R B Park.

43 records · Page 3Linked to original sources
PubMed1966

Effect of hydrolytic enzymes on the photosynthetic efficiency and morphology of chloroplasts.

Both lipase from runner beans and a protease (pronase) initially cause increased intensity dependence of the DCPIP Hill reaction of spinach chloroplasts. This is followed by an increase in the extrapolated zero intensity quantum requirement. Pronase treatment of the chloroplasts causes rapid changes in absorption and ORD spectra, whereas the effect of lipase treatment is much less pronounced. Long treatments of the thylakoids with the lipase and protease cause unique morphological changes within the membrane. These changes are used to assign chemical compositions to some of the structures revealed by freeze-etching.

Journal Article↗
PubMed1965

Substructure of chloroplast lamellae.

(1) Chloroplast lamellae, like many other membranes, are composed of 90-A subunits. (2) The way in which the 90-A units associate with one another determines the quantasome structures of the membrane. There appear to be four 90-A subunits per quantasome in the most highly organized arrays. In at least some cases, the way in which the subunits bind one to another is under environmental control. (3) Extraction experiments are consistent with a model in which the membrane lipid surrounds the protein framework of the membrane.

Chloroplasts↗