Some off the top of my head responses (with help from a friend) to a set of questions from another topic site are as follows. DNA/RNA
1. What is the estimated minimum nucleotide length of DNA or RNA needed for a self-reproducing organism?
The lower limit for a living non virus is usually considered around 4,000 genes or about 400,000 DNA base pairs (bacteria genes are about 1,000 base pairs long - see Clark and Russell Molecular Biology 2000). Others feel the number is lower. According to some scientists at UNC, "[t]he minimum number of protein-producing genes a single-celled organism needs to survive and reproduce in the laboratory is somewhere between 265 and 350." See http://www.sciencedaily.com/releases/1999/12/991213052506.htm
Time will tell. For humans the DNA from an average person will stretch to the sun and back 600 times.
A reason why a difference in opinion exists about the minimum number of genes required for a living organism is because the larger figure represents the actual number of genes known in free-living organisms, and the smaller figures represents an estimate based largely on a parasitic organism and the assumption by evolutionists that the environment in the early earth that supposedly produced the first living thing would also be chemically supportive of it. They assume that some specialized micro environment existed that was filled with amino acids, possibly proteins, lipids, and who knows what all, forming a sort of inorganic womb that would nurture the primitive life form it had just produced. Of course DNA is only the software and without the hardware (the scores of proteins that allow translation and transcription such as polymerase the system is useless.
2. How long of polymers (nucleotide length) of DNA or RNA have been formed in labs under realistic conditions? How close is this to the answer to question # 1. By "machine" I am not aware of any known limit, but this procedure is human designed so it is only of indirect interest.
3. Will a forming polymer tend to lengthen or break apart under naturalistic conditions? It will break apart and this is why repair enzymes are critical. otherwise it would not last long even in the cell.
4. Do all the sugars in DNA and RNA have to be either "right handed (D)" or "left handed (L)" or will a combination of both in the same molecule lead to functional nucleic acids?
The sugars have to match the whole system, especially the enzyme system that makes them. As far as I know all of the sugar backbones of RNA and DNA are only D isomers. Optical activity purity is biologically necessary for proper coiling for both amino acids and also for the sugars.I understand that getting the right kinds of sugars is statistically vastly more difficult than optically pure amino acids.
5. If only one type of sugar (D or L) will work, how could long polymers of DNA/RNA form from a 50/50 mixture? Has there been any naturalistic condition found which could separate the two out, leading to polymers of only 1 type being formed? Polymers could form but they would not be functional. I would think that they would be sticky like candy