scholarly journals UPTAKE OF ORGANIC MATERIAL BY AQUATIC INVERTEBRATES. IV. THE INFLUENCE OF SALINITY ON THE UPTAKE OF AMINO ACIDS BY THE BRITTLE STAR, OPHIACTIS ARENOSA

1966 ◽  
Vol 131 (1) ◽  
pp. 172-185 ◽  
Author(s):  
GROVER C. STEPHENS ◽  
RAGHUNATH A. VIRKAR
Keyword(s):  
Amino Acids ◽  
Organic Material ◽  
Aquatic Invertebrates ◽  
Brittle Star

Uptake of organic material by aquatic invertebrates

1969 ◽  
Vol 3 (4) ◽  
pp. 352-355 ◽  
Author(s):  
D. J. Reish ◽  
G. C. Stephexs
Keyword(s):  
Organic Material ◽  
Aquatic Invertebrates

scholarly journals Entropy Production as the Origin of Information Encoding in RNA and DNA

2019 ◽  
Author(s):  
Julián Mejía ◽  
Karo Michaelian
Keyword(s):  
Amino Acids ◽  
Nucleic Acids ◽  
Entropy Production ◽  
Organic Material ◽  
Photon Flux ◽  
Chemical Affinity ◽  
Equilibrium Thermodynamic ◽  
Information Encoding ◽  
Thermodynamic Potentials ◽  
Rna And Dna

Ultraviolet light incident on organic material can initiate its spontaneous dissipative structuring into chromophores which can catalyze their own replication. This may have been the case for one of the most ancient of all chromophores dissipating the Archean UVC photon flux, the nucleic acids. Oligos of nucleic acids with affinity to particular amino acids which foment UVC photon dissipation would have been selected through non-equilibrium thermodynamic imperatives which favor entropy production. Indeed, we show here that those amino acids with characteristics most relevant to fomenting UVC photon dissipation are precisely those with greatest chemical affinity to their codons or anticodons. Entropy production could thus provide an explanation for the accumulation of information in nucleic acids relevant to the dissipation of the externally imposed thermodynamic potentials. The accumulation of information in this manner provides a link between evolution and entropy production.

Dynamics of Enamel Formation in the Rat Incisor Tooth

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 950-979 ◽  
Author(s):  
C.P. Leblond ◽  
H. Warshawsky
Keyword(s):  
Amino Acids ◽  
Cell Membrane ◽  
Organic Material ◽  
Organic Matrix ◽  
Incisor Tooth ◽  
Enamel Formation ◽  
Rat Incisor ◽  
Full Size ◽  
Matrix Deposition ◽  
Mineral Deposition

Enamel formation was reviewed by morphology and radioautography in rat incisors. Labeled amino acids and sugars were used as matrix precursors whereas labeled calcium monitored mineral deposition. All ameloblasts synthesize organic material, but only cells in the zone of secretion release labeled matrix. The pattern of matrix deposition indicates that enamel rods are elaborated by Tomes' processes within cavities formed by interrod partitions. The latter are elaborated by cytoplasmic projections from adjacent ameloblasts. Initially - labeled matrix is added as a band near the cells. With time the label randomizes throughout the entire immature enamel and most of it is lost in the zone of maturation. However, a glycoprotein component attributed to remnants of Tomes' process membrane persists in mature enamel. Labeled calcium is incorporated into crystals which grow at a uniform rate throughout the entire layer of enamel in the zone of secretion and up to the middle of the zone of maturation. The ribbon-like crystals are built close to the cell membrane and elongate as the cell recedes. Crystal elongation occurs in the same location as new matrix is deposited; that is, rod crystals are related to Tomes' processes and interrod crystals, to cytoplasmic projections. The crystals grow to full size mainly by thickening and this growth presumably displaces the organic matrix.

scholarly journals FREE AMINO ACIDS IN SOME AQUATIC INVERTEBRATES

1959 ◽  
Vol 117 (2) ◽  
pp. 371-381 ◽  
Author(s):  
JOHN W. SIMPSON ◽  
KENNETH ALLEN ◽  
JORGE AWAPARA
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Aquatic Invertebrates
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