Fact 4
Prebiotic forces cannot create a basic cell by arranging the four basic building blocks.
DNA and its stored information/data is useless by itself. DNA must be in a living cell that can retrieve and transmit the data through RNA to produce proteins.
Credit: Martina Maritan, Scripps Research
Make the Simplest Cells - 4 Building Blocks
Nobody has made any of the higher-order structures needed for the simplest of cells
Requirements for the simplest form of life, single cell bacteria
"This minimal gene set included genes for:
"DNA replication, repair, restriction, and modification;
"a basic transcription machinery;
"aminoacyl-tRNA synthesis;
"tRNA maturation and modification;
"ribosomal proteins;
"ribosome function, maturation, and modification;
"translation factors;
"RNA degradation;
"protein processing, folding, and secretion;
"cellular division; transport;
"and energetic and intermediary metabolism (glycolysis, proton motive force generation, pentose phosphate pathway, lipid metabolism, and biosynthesis of nucleotides and cofactors).
"Those authors did not include rRNA or tRNA genes, and they recognized that the basic substrate transport machinery could not be clearly defined, even though this minimal cell would rely greatly on the import of several substrates, including all 20 amino acids (for which it had no biosynthetic ability)."
Microbiol Mol Biol Rev. 2014 Sep; 78(3): 487–509.
doi: 10.1128/MMBR.00050-13
Systems Biology Perspectives on Minimal and Simpler Cells
Joana C. Xavier⁽ᵃ,ᵇ⁾, Kiran Raosaheb Patil⁽ᵇ⁾, and Isabel Rocha⁽ᵃ⁾
PMCID: PMC4187685
PMID: 25184563
Cell Membrane
The Complex Cellular Membrane
Researchers have identified thousands of different lipid structures in cell membranes.
When making synthetic vesicles-synthetic lipid bilayer membranes-mixtures with monoacyl lipids can destabilize the system- so how are these avoided?Lipid bilayers surround subcellular organelles, such as nuclei and mitochondria, which are themselves microsystem assemblies. Each of these has their own lipid composition, different from the host vesicle.
Lipid bilayers have a non-symmetric distribution between inner and outer surfaces.
Protein-lipid complexes are the required passive transport sites and active pumps for the passage of ions and molecules through bilayer membranes, often with high specificity.
All lipid bilayers have vast numbers of polycarbohydrate appendages, known as glycans. These are essential for cell regulation. Consider the hexamer of the carbohydrate D-pyranose→ >1 trillion constitutional and stereochemical isomers. Eliminating any class of carbohydrates from an organism results in its death.