When various types of molecules such as water, aldehydes, ammonia, and hydrogen cyanide are available, amino acids can be formed under certain conditions. The polyhydroxylated aldehydes, carbohydrates, are formed from formaldehyde as well when conditions are fixed. If these species existed in a same period on the ancient earth, a series of polyhydroxylated amino acids could have been formed. If the type of amino acids were available, life could have relied on the array of amino acids. In turn, we might have evolved to use them. However, there are no known such molecules, as far as I know. Carbohydrates consisting of greater number of carbon atoms, say more than four carbons, tend to form intramolecular acetals, hemiacetals. This may explain some. But then why did not shorter ones react with ammonia and so on? Does any one have any answer or idea about this?
Vladimir,
Thank you for your answer. I appreciate it. I thought no one is interested.
I recognize the some carbohydrates can be regarded is "amino acid"; like sialic acid having acylated amino function and a carboxylic acid. Also some others are, like you said. But all of these requires enzymes. Enzymes are coded on the gene and produced by some organism.
I am rather interested possible prebiotic formation of polyhydroxylated amino acids, especially, alpha amino acids, that might had chance, if they were formed, to be used in the process of generation of "life-related materials" before life started on earth.
Dear Muhammad,
Thank you for your deep consideration.
My main question towards my question about the polyhydroxylated amino acids relates to a basic question how all the living thing created and for that what was the initial state of forming life as you noticed. As I consider about the question, I came to think that spatiotemporal resolution might be key factor. I cannot discuss about my hypothesis right now in detail because I have engaged in a research to examine it. But some of my consideration relates to the following. Initially formed carbohydrates mainly consists of carbon, oxygen, and hydrogen. A formose reaction is thought to be an initial reaction which is followed by aldol reaction. As you pointed out, there are other carbohydrates contain nitrogen, but these are considered to be formed after simple sugar formation by chemical process and biological transformation, which are not my question. A question here is that why ammonia could not be a player to form the early formed sugars. My guess is that they were not available for some reason. Ammonia reacts with carbonyl compounds first and so some of amino acids and purin and pyrimidine bases (but not necessarily all of them) were formed except for sugars. Why? My conclusion is somehow ammonia was not available when sugars were formed. This is the only way I can think of and my next question is how it was possible. And the key to the second question is time- or space-discrimination.
Now a days, not many show interests on these basic questions but I think it is very important. I just curious about why we (not just human) exist.
- Badges
- Science topic
- Similar topics
- Instrumentation Engineering
- Instruments