RNA world theory, a possible theory for life origin
I think the RNA world theory, combined with other process, including clay chemistry and deep sea vents activities, is an extremely possible theory for origin of life. With addition of icy chemistry, the RNA world theory may also help us to find life outside Earth. “The RNA world theory is widely accepted by origin-of-life theorist” (Ricardo and Szostak 2009)
The RNA world theory was initially proposed 1967 for origin of life. It includes the following steps: First, there are many nucleotides on Earth. Second, there is a chemical process to synthesize single-strand RNAs. Next step is to wait until there is an RNA molecule is produced with the right sequence and folded into the right
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The unique potential of RNA molecules to act both as an information carrier and as catalyst forms the basis of the RNA world hypothesis. an RNA molecule with an appropriately folded shape can serve as an enzyme.” (Alberts B,2002). The ability of RNAs as enzyme make a powerful assertion for the RNA world theory. “The demonstration that ribosomal peptide synthesis is a ribozyme-catalyzed reaction makes it almost certain that there was once an RNA World” (Orgel Leslie E. 2004). Additionally, I found out that RNA as the enzyme is not only synthesized in cells, but also in labs, so the natural RNAs will ability as catalysis may not be impossible. “Researchers directed the evolution of RNAs that could catalyze monomer synthesis, from the production of ribose to the attachment of the sugar to nucleobases. Others bred RNA enzymes, or ribozymes, that could conduct the steps of translation, phosphorylate other polymers, join molecules together, or break them apart.” (Jef Askt, 2014)
There are some suspicions on the RNAs’ ability to pass the catalysis properties to their offspring. “There is no way to encode the bond type between nucleotides. In other words, the RNA’s offspring will not be identical to the parent, and therefore the offspring will not have the replication ability” (Anne P) However, I think RNA replication is a reliable process since the shape is determined by nucleotide
Unit 2 - The Chemical Basis of Life Part 1 - Molecules of Life Part 2 - DNA Replication and Protein Synthesis Enzymes DNA Structure DNA Replication Protein Synthesis Overview Transcription Translation Mutations Part 3 - Cellular Respiration and Photosynthesis Unit 3 - Genetics
RNA is much more chemically active and automatic than DNA, but it is also unstable, therefor prehistoric “ribo-organisms” came up with DNA through an evolutionary trial and error process due to it being faster and more accurate. LUCA, or the Last Universal Common Ancestor is then introduced. It is believed to be a bacterium that lived in a hot marine environment. LUCA is now believed to be more of a protozoan because bacteria would have dropped the extra
The fragments that were analyzed by Muck were found to be functional matches to an RNA ligase and a queuine tRNA-ribosyltransferase (NCBI). Both of these functional matches were to the phage SamuelLPlaqson (NCBI).
5. RNA developed before DNA because RNA could have been small and still would exist if it was able to fold into a more stable formation. The sequences that folded into a stable formation would be more likely to survive and duplicate that sequence.
There are three types of RNA: mRNA, tRNA, and rRNA. Messenger RNA (mRNA) is synthesized from a gene segment of DNA which ultimately contains the information on the primary sequence of amino acids in a protein to be synthesized. The genetic codes is translated is for mRNA, not DNA. The messenger RNA carries the code from the nucleus to the ribosome in the cytoplasm where protein synthesis occurs. It also carries the genetic information copied from the DNA in the form of a series of three-base code “words”, also known as triplets, each of which specifies a particular amino acid. Each nucleotide triplet, called a codon, can be “read” from the mRNA and translated into an amino acid to be incorporated into a protein being synthesized. Messenger RNA is a
The properties of RNA that have convinced investigators that it may have played an important role in the evolution of life in earth is that RNA is able to encrypt information and is able to assemble chemical reactions. Before ribozymes were discovered, proteins were only able to catalyze and only nucleic acids encrypted information. Obviously, RNA can do both and since the discovery of it, many scientists now believe RNA played an important role in the evolution of life.
Deep Sea Vent Hypothesis: This hypothesis stated that chemical reactions in the oceans hydrothermal vents of the ocean created living cells. This theory was presented in 1977 by scientists Eoghan Reeves, Jeff Seewald, and Jill McDermott. They have found that biological communities are thriving in a chemical soup rich in hydrogen, carbon dioxide and sulfur. From these findings they proposed that hydrothermal vents has all the necessary components that would be necessary for life to start on Earth. Scientist suspected that a compound called methanethiol was the the thing that started all
The process of mutation changing to the genetic code was observed and the results of it. The main outcomes looked for in this lab were to be able to describe the basic structure of DNA and RNA, be able to design a simulation model that shows the replication of both RNA and DNA, to be able to create models in a simulation that demonstrate both transcription and
“The double helix is indeed a remarkable molecule. Modern man is perhaps 50,000 years old, civilization has existed for scarcely 10,000 years and the United States for only just over 200 years; but DNA and RNA have been around for at least several billion years. All that time the double helix has been there, and active, and yet we are the first creatures on Earth to become aware of its existence.” Francis Crick (1916–2004).
Still, how you can revise life coming from non-life, from a frog coming from a non-frog, or from a human coming from a non-human, when such theory cannot test or prove such? The same for the big bang theory; how the first star formed is
That's it... right now the Best Explanation for the Origins of Life is (Design) based on what we have witnessed in the passed and the extraordinary workings within all living cells. Proteins appear to be programmed to perform (Specific Task) based of (Specific Instruction) guided to selection by (Specific Instruction) generated by DNA, that by the way Requires Proteins to self replicate, a sort of Chicken and the Egg paradox!
In Nielsen’s article “Designing a New Molecule of Life”, he goes into detail of the many factors PNA will offer in the future. PNA can create a breakthrough drug, or may even create artificial life one day. Scientists say the PNA has many similarities as the molecules that have been thought to be the beginning of life. Though the
Life has continually perplexed and fascinated individuals since the dawn of mankind. The subject’s complexity is so great even over the course of human existence only a minute fraction of its mysteries have been unraveled. A phenomenon which has always intrigued scientists is the origin of life on Earth, and in recent years significant advancements have been made in the understanding of this enigma. This essay will briefly outline two theories regarding life’s origin on Earth to further comprehend why an explanation for this phenomenon has been so difficult to reach.
According to astronomical research and geological evidence, scientist indicate the universe is approximately thirteen thousand eight hundred and twenty billion years old. The first link to humanity started with a primate group called Ardipithecus. While our ancestors have been around for about six million years, the modern form of humans only evolved about two hundred thousand years ago. The age of the Earth is estimated about four point fifty four billion years because that is the age of the oldest rocks with fossil evidence of life on earth. The oldest rocks on Earth found to date are the Acasta Gneisses in northwestern Canada near the Great Slave Lake, which are four point three billion years old. The study of the origin of life on Earth, more specifically abiogenesis, is the natural process of life arising from non-living matter. Life on Earth is believed to have began from organic compounds about three point eight to four billion years ago. Despite several competing theories for how life arose on Earth scientist only know when life first appeared on Earth and are still far from answering how it appeared. Since it is hard to prove or disprove them, no fully accepted theories of the origin of life exists.
One of the main theories is that life started by chemical means in a rock where water, methane, ammonia and hydrogen were all present then with the added effect of lightening simple organic molecules formed the building blocks of life. There was an experiment that was conducted in 1953 by Miller and Urey that supports that the conditions above could stimulate organic compounds to form. *copied “ The Miller-Urey experiment attempts to recreate the chemical conditions of the primitive Earth in the laboratory, and synthesized some of the building blocks of life.