Month: September 2022

CHIRAL METAMATERIALS. "A new class of materials able to exert a repulsive force when they are placed in extremely close proximity to each other. The repulsive force, which harnesses a quantum phenomenon known as the Casimir effect, may someday allow nanoscale machines to overcome mechanical friction." https://lnkd.in/etbCjEi) View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and ends this weekend on the theme of protoplasm, that wonderful structured gel that creates proximate reaction segregation and order in cells. Without either property, cells, as we know them, would not be possible. Metabolism is composed of interconnected strings of reactions, shunting electrons, protons and reactants, often requiring separate reaction jugs, and is made possible by proximate segregation. View in LinkedIn

OLD VIEWPOINT. “The protoplasm: Bag of enzymes or organised laboratory? The emerging view of the cell tended to disregard protoplasmic singularity and suggested that biological reactions were governed by random encounters and simple, mass action relationships (i.e. the bag of enzymes view).” https://lnkd.in/dgDXdM5 View in LinkedIn

EMERGING SOPHISTICATION. “In 1919, Ritter suggested that the cell interior was replete with ‘highly differentiated’ molecules of varying molecular weight dispersed throughout coexisting phases. The resulting ‘metaplasmic constituents’ acted simultaneously to generate ‘special apparatus and an organised laboratory’.” http://onlinelibrary.wiley.com/doi/10.1111/febs.13744/full View in LinkedIn

THE CHEMICAL MAZE. “Peters later elaborated on this view by suggesting that surface effects direct the formation of ‘an organised network of protein molecules, forming a three-dimensional mosaic extending throughout the cell’. The mosaic was purported to constrain proteins, regulating their activity and allowing for rapid information transduction.” http://onlinelibrary.wiley.com/doi/10.1111/febs.13744/full View in LinkedIn

EMERGING MODERN VIEW. “The importance of subcellular structure in maintaining the integrity of metabolic phenomena was demonstrated by Krebs.” http://onlinelibrary.wiley.com/doi/10.1111/febs.13744/full View in LinkedIn

STRUCTURED GEL. “The entire macromolecular apparatus is associated with large particulates as a basic structure of cellular organisation...the authors suggested the advantages of such organisation in reducing the dimensionality and directing substrate diffusion directly between metabolically related enzymes.” http://onlinelibrary.wiley.com/doi/10.1111/febs.13744/full View in LinkedIn

PROXIMATE REACTIONS. “Srere postulated that enzymes assembled into multimeric complexes to facilitate the vectorial flow of substrates and/or intermediates along a metabolic pathway. Enzyme organisation was predicted to decrease the diffusion time of substrates and/or intermediates between pathway steps, to stabilise transient intermediates and to minimise cross-reactions with competing pathways.” http://onlinelibrary.wiley.com/doi/10.1111/febs.13744/full View in LinkedIn

REACTION STRINGS. “The kinetic advantages of an immobilised system of malate dehydrogenase and citrate synthase over the free enzyme system were subsequently demonstrated.” http://onlinelibrary.wiley.com/doi/10.1111/febs.13744/full View in LinkedIn