What steps are required to create a first living self-replicating cell?
Six basic properties are shared by all living cells on earth. Without wishing to sound like a textbook, let’s just enumerate them. 1
i. a continuous supply of reactive carbon for synthesizing new organics;
ii. a supply of free energy to drive metabolic biochemistry – the formation of new proteins, DNA,
and so on;
iii. catalysts to speed up and channel these metabolic reactions;
iv. excretion of waste, to pay the debt to the second law of thermodynamics and drive chemical
reactions in the correct direction;
v. compartmentalization – a cell-like structure that separates the inside from the outside;
vi. hereditary material – RNA, DNA, or an equivalent, to specify the detailed form and function.
assembly of boundary membranes
• formation of energy capturing capabilities by the boundary membrane
• encapsulation of macromolecules (like proteins, RNA, and DNA) within the boundary membrane
• introduction of pores into the boundary membrane that can funnel raw materials into the interior space
• production of systems that allow the macromolecules to grow
• generation of catalysts that speed up the growth of the encapsulated macromolecules
• provision for the macromolecules to replicate
• introduction of information into one set of macromolecules that directs the production of other macromolecules
• development of mechanisms to cause the boundary membrane to subdivide into two smaller systems that can grow
• production of the means to pass information-containing macromolecules to the daughter products of the subdivision process
life in its bare minimal form requires genes that control DNA replication, cell division, protein synthesis, and assembly of the cell membrane. Minimal life also depends upon genes that specify at least one biochemical pathway that can extract energy from the environment
All life is cellular.
All living things are from 50 to over 90% water, the source of protons, hydrogen and oxygen in photosynthesis, and the solvent of biomolecules.
The major elements of covalently bound biomolecules are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
There is a universal set of small molecules: (i.e. sugars, amino acids, nucleotides, fatty acids, phospholipids, vitamins, and coenzymes.)
The principle macromolecules are proteins, lipids, carbohydrates, and nucleic acids.
There is a universal type of membrane structure (i.e. the lipid bilayer).
The flow of energy in living things involves the formation and hydrolysis of phosphate bonds, usually ATP.
The metabolic reactions of any living species is a subset of a universal network of intermediary metabolism (i.e. glycolysis; the Krebs cycle, the electron transport chain)
Every replicating cell has a genome made of DNA that stores the genetic information of the cell which is read out in sequences of RNA and translated into protein.
All growing cells have ribosomes, which are the sites of protein synthesis.
All living things translate information from nucleotide language through specific activating enzymes and transfer RNAs.
All replicating biological systems give rise to altered phenotype due to mutated genotypes.
Reactions that proceed at appreciable rates in all living cells are catalyzed by enzymes.
Biologists and paleontologists have defined five basic questions that need to be answered when discussing the origin of life.
(1) Where did the raw materials for life come from?
(2) How did monomers develop?
(3) How did polymers develop?
(4) How did an isolated cell form?
(5) How did reproduction begin?
Either life emerged by a fortuitous accident, spontaneously through self-organization by unguided stochastic coincidence, natural events that turned into self-organization in an orderly manner without external direction, chemical non-biological, purely physico-dynamic kinetic processes and reactions influenced by environmental parameters, or through the direct intervention, creative force and activity of an intelligent agency, a powerful creator.
Which option makes more sense ?
1. Lane, the vital question, page 64
http://www.utdallas.edu/~cirillo/nats/day18.htm
Six basic properties are shared by all living cells on earth. Without wishing to sound like a textbook, let’s just enumerate them. 1
i. a continuous supply of reactive carbon for synthesizing new organics;
ii. a supply of free energy to drive metabolic biochemistry – the formation of new proteins, DNA,
and so on;
iii. catalysts to speed up and channel these metabolic reactions;
iv. excretion of waste, to pay the debt to the second law of thermodynamics and drive chemical
reactions in the correct direction;
v. compartmentalization – a cell-like structure that separates the inside from the outside;
vi. hereditary material – RNA, DNA, or an equivalent, to specify the detailed form and function.
assembly of boundary membranes
• formation of energy capturing capabilities by the boundary membrane
• encapsulation of macromolecules (like proteins, RNA, and DNA) within the boundary membrane
• introduction of pores into the boundary membrane that can funnel raw materials into the interior space
• production of systems that allow the macromolecules to grow
• generation of catalysts that speed up the growth of the encapsulated macromolecules
• provision for the macromolecules to replicate
• introduction of information into one set of macromolecules that directs the production of other macromolecules
• development of mechanisms to cause the boundary membrane to subdivide into two smaller systems that can grow
• production of the means to pass information-containing macromolecules to the daughter products of the subdivision process
life in its bare minimal form requires genes that control DNA replication, cell division, protein synthesis, and assembly of the cell membrane. Minimal life also depends upon genes that specify at least one biochemical pathway that can extract energy from the environment
All life is cellular.
All living things are from 50 to over 90% water, the source of protons, hydrogen and oxygen in photosynthesis, and the solvent of biomolecules.
The major elements of covalently bound biomolecules are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
There is a universal set of small molecules: (i.e. sugars, amino acids, nucleotides, fatty acids, phospholipids, vitamins, and coenzymes.)
The principle macromolecules are proteins, lipids, carbohydrates, and nucleic acids.
There is a universal type of membrane structure (i.e. the lipid bilayer).
The flow of energy in living things involves the formation and hydrolysis of phosphate bonds, usually ATP.
The metabolic reactions of any living species is a subset of a universal network of intermediary metabolism (i.e. glycolysis; the Krebs cycle, the electron transport chain)
Every replicating cell has a genome made of DNA that stores the genetic information of the cell which is read out in sequences of RNA and translated into protein.
All growing cells have ribosomes, which are the sites of protein synthesis.
All living things translate information from nucleotide language through specific activating enzymes and transfer RNAs.
All replicating biological systems give rise to altered phenotype due to mutated genotypes.
Reactions that proceed at appreciable rates in all living cells are catalyzed by enzymes.
Biologists and paleontologists have defined five basic questions that need to be answered when discussing the origin of life.
(1) Where did the raw materials for life come from?
(2) How did monomers develop?
(3) How did polymers develop?
(4) How did an isolated cell form?
(5) How did reproduction begin?
Either life emerged by a fortuitous accident, spontaneously through self-organization by unguided stochastic coincidence, natural events that turned into self-organization in an orderly manner without external direction, chemical non-biological, purely physico-dynamic kinetic processes and reactions influenced by environmental parameters, or through the direct intervention, creative force and activity of an intelligent agency, a powerful creator.
Which option makes more sense ?
1. Lane, the vital question, page 64
http://www.utdallas.edu/~cirillo/nats/day18.htm
Last edited by Admin on Tue Jul 14, 2020 9:12 am; edited 5 times in total