"Life" is a biological system which independently performs all four of the following functions:
Metabolism is the utilization of materials and also of energy taken in from the envronment, which is transduced and stored in the form of high-energy chemical bonds (esp phosphate bonds), and then retrieved and used for the growth and repair of the organism. Energy metabolism in all known life occurs only through ATP (Adenosine Triphosphate), ADP and AMP (...Mono...), and every known living system requires AMP in its metabolism process, ...Therefore, any adequate origin-of-life scheme must account for the original synthesis of AMP in the first organisms, including the origin of the chemical pathway (including enzymes) that living things use today to make AMP ...and laboratory experiments must demonstrate that each step could sustainably occur in conditions that are probable in nature.
2. Biological "Information" Use and Processing
Any living thing writes and stores biological information, and uses it to direct metabolism, to assemble the structures of the organism, and to reproduce. All life copies and passes along such biological information to offspring. ----To give a definition of Biological "Information" (see "...Proof of Intel.Design..."(link)), Information theorists call it : The "aperiodic specified complexity" in life's biochemistry. Such aperiodic specified complexity is found in life's "informational" molecules, specifically, in DNA molecules and functional (folding) protein molecules. As Thaxton says, "DNA is called an informational molecule because its unique structure functions as the central part of an elaborate communication system within the cell". The specified sequence of the nucleotides in DNA contains the information of life. This information conveys instructions to the cell in order to build the structures of the cell, and to direct the metabolism and other biochemical processes and work of life. In DNA is found the symbolic, indirect representation of life's instructions; and this is "written" into codons, which act as the "words" of a nitrogen based "language", which is in turn translated into the end-product of specified amino acid sequences, or proteins, which are the molecular "machines" which carry out the biochemical processes of life in the cell.
All living things make other living copies of themselves. In all organisms DNA is used in this process of reproduction, and thus, an adequate origin-of-life scheme must adequately account for the origin of the DNA/RNA genetic system of reproduction used by all known biological life. Such a scheme must demonstrate by lab experiments the abiotic origin and assembly of the component parts to make DNA/RNA. In addition, an adequate scheme must adequately account for the abiotic origin of functional proteins (required to build DNA/RNA), including the 20 amino acids of which they are made.
4. Cell Membrane Maintenance
All life builds and maintains some sort of semi-permeable cell membrane around itself which sections itself off from the surrounding environment, and this membrane is used to selectively absorb nutrients and to excrete waste-products.
Any chemical "replicator" which doesn't use biological information in replication and metabolism and membrane maintenance, is not actually independent life. Therefore, RNA strands (alone), DNA strands (alone), ribozymes, prions, viroids, and viruses shall not be considered free-living organisms, since they fail to meet the above well-recognized characteristics of independent "life." So, mechanism(s) for the origin of the above four life-characteristics must be shown (and confirmed in the lab) to be within a reasonable statistical probability of arising from non-living chemicals (abiogenesis), ...all without the intervention of intelligence.