Bioengineering Heat Transfer by Young I. Cho (Eds.)
By Young I. Cho (Eds.)
Read or Download Bioengineering Heat Transfer PDF
Best biophysics books
Extra info for Bioengineering Heat Transfer
A number of experiments have confirmed the possibility of synthesizing organic constituents from the components present in the primitive atmosphere. Laboratory chemists have tried synthesizing the different families of key molecules: nucleic acids such as RNA, proteins that orchestrate chemical reactions, and phospholipids, which ensure the cohesion of cellular structures in water. In 1953, Stanley Miller produced amino acids by sending electric sparks through a mixture of methane, hydrogen, ammonia and water vapour.
It’s like the paradox of the chicken and the egg: biologists ask which came first. In the early 1980s, with the discovery of RNA molecules (ribozymes) capable of catalysing in vivo chemical reactions in themselves and other types of molecules, it became possible to imagine primitive RNA ORIGINS AND DYNAMICS 43 molecules capable of transmitting genetic information and catalysing their own replication in the absence of proteins. Such RNAs would themselves have assumed the functions that are now accomplished by DNA and proteins.
On an extremely macroscopic scale, four ecoclimatic zones can be identified: tropical, hot and humid; temperate humid; polar; and arid. On a more differentiated scale, it appears that different regions with identical climatic conditions are occupied by comparable natural ecosystems. Vegetation has the virtue of being a quite reliable indicator for plotting the interplay of such diverse factors as geomorphogenesis and climate on rather large spatial scales. The boundaries of large vegetation formations mark the discontinuities apparent in the natural world.