Observations on Cellular Structures of Porphyridium cruentum

Dynamic fluorescence photobleaching of single phycobilisome complexes from Porphyridium cruentum

Granules Associated with the Chloroplast Lamellae of Porphyridium Cruentum

Small granules with a diameter of approximately 350 A are attached to the chloroplast lamellae of the red alga Porphyridium cruentum. To some extent, their size depends on the culture conditions and the age of the cell. It was possible to preserve the granules only with aldehyde prefixation. It can be seen that fixed or negatively stained granules are comprised of smaller subunits. The granules...

Isolation and Function of Allophycocyanin B of Porphyridium cruentum.

Allophycocyanin B was purified to homogeneity from the eukaryotic red alga Porphyridium cruentum. This biliprotein is distinct from the allophycocyanin of P. cruentum with respect to subunit molecular weights, and spectroscopic and immunological properties. The purified allophycocyanin B has a long wavelength absorption maximum at 669 nm at room temperature and at 675 nm at -196 C while the flu...

Efficiency of energy transfer from photosystem II to photosystem I in Porphyridium cruentum.

The yield of energy transfer from photosystem II to photosystem I in Porphyridium cruentum varies from a minimum value of about 0.50 when the photosystem II reaction centers are all open to a maximum value between 0.90 and 0.95 when the centers are all closed.

Effective Absorption Cross-Sections in Porphyridium cruentum: Implications for Energy Transfer between Phycobilisomes and Photosystem II Reaction Centers.

Effective absorption cross-sections for O(2) production by Porphyridium cruentum were measured at 546 and 596 nanometers. Although all photosystem II reaction centers are energetically coupled to phycobilisomes, any single phycobilisome acts as antenna for several photosystem II reaction centers. The cross-section measured in state I was 50% larger than that measured in state II.