Membranes
The enclosure of cellular machinery within a protective membrane is a feature seen by xenobiologists on many independent worlds. The principle behind a cell membrane is self-assembly. In baseline Terragen lifeforms, phospholipid molecules constitute these membranes. The phospholipid has a hydrophilic, negatively charged phosphate head and a hydrophobic alkyl tail. It is energetically an entropically favorable for these molecules to then assemble into *bilayers* where the tails sit in the middle of the structure, isolated from water and the heads on the outside where they can interact with water.
The membranes in the Muuhomic biosphere operate on a similar principle but with key differences. The molecule membranes are constructed from is acrylonitrile (CH2CHCN), which is much shorter than a phosopholipid and this produces a thinner membrane. Because the seas of Muuhome are primarily filled with a non-polar mix of methane and ethane, the hydrophobic vinyl group of the acetonitrile is driven to self-assemble on the *outside* of the membrane, while the polar nitrile/cyanide group is isolated away from unfavorable interactions with the non-polar environment in the center.
The geometry of acrylonitrile molecules favors the large-scale shaping of these bilayers into hollow spheres called *azotosomes*. When filled with the machinery of life, these azotosomes become cell membranes. On Muuhome, most higher bionts have a cell membrane with more than one layer, assembling azotosomes in concentric spheres like an onion. The thin nature of the bilayer means single-layer membranes are much more permeable than those of baseline Terragens, which is only conducive to the rudimentary cell machinery of bionts in the simple *Unamura* clade.
The enclosure of cellular machinery within a protective membrane is a feature seen by xenobiologists on many independent worlds. The principle behind a cell membrane is self-assembly. In baseline Terragen lifeforms, phospholipid molecules constitute these membranes. The phospholipid has a hydrophilic, negatively charged phosphate head and a hydrophobic alkyl tail. It is energetically an entropically favorable for these molecules to then assemble into *bilayers* where the tails sit in the middle of the structure, isolated from water and the heads on the outside where they can interact with water.
The membranes in the Muuhomic biosphere operate on a similar principle but with key differences. The molecule membranes are constructed from is acrylonitrile (CH2CHCN), which is much shorter than a phosopholipid and this produces a thinner membrane. Because the seas of Muuhome are primarily filled with a non-polar mix of methane and ethane, the hydrophobic vinyl group of the acetonitrile is driven to self-assemble on the *outside* of the membrane, while the polar nitrile/cyanide group is isolated away from unfavorable interactions with the non-polar environment in the center.
The geometry of acrylonitrile molecules favors the large-scale shaping of these bilayers into hollow spheres called *azotosomes*. When filled with the machinery of life, these azotosomes become cell membranes. On Muuhome, most higher bionts have a cell membrane with more than one layer, assembling azotosomes in concentric spheres like an onion. The thin nature of the bilayer means single-layer membranes are much more permeable than those of baseline Terragens, which is only conducive to the rudimentary cell machinery of bionts in the simple *Unamura* clade.
