Evolutionary Biology Origins of Life II: Primeval environments and the origins of RNA by David Warmflash, MD, Nathan H Lents, Ph.D. Reading Quiz Teach with this If three ingredients are present - sugars, amino acids, and fatty acids - cells will spontaneously emerge from nonliving chemistry. true false Most scientists believe that the first large functional macromolecule to appeared on Earth was RNA DNA sugar an amino acid What was necessary on early Earth in order for RNA molecules to form, copy each other, and evolve? The ocean Protein enzymes A confined space DNA Just as fatty acids are attracted to each other and form ______, phospholipids are attracted to each other and form ______. protein enzymes, RNA polymers RNA polymers, protein enzymes micelles, membranes membranes, micelles When a meteorite hit the Earth in 1969 and was analyzed, what did scientists find? Sugars Fewer amino acids than are found in life on Earth Fossil remains of once-living organisms Only inorganic molecules Scientists who wish to experiment in an environment like that found on Earth 4 billion years ago can look at living cells. cold oceans. the structure of macromolecules. volcanoes. What advantage would free fatty acids offer over phospholipids when it came to forming primeval membranes? Free fatty acids were more efficient than phospholipids at forming membranes. Phospholipids were more sensitive to pH than free fatty acids. RNA building blocks moved around more among liposomes that were made from phospholipids than from those made of fatty acids. Liposomes made from free fatty acids are more dynamic than those made from phospholipids. Scientists David Deamer and Jack Szostak took different approaches to discovering how RNA polymers could have formed on early Earth. Both found that their methods resulted in RNA polymerization through different ways that lipids helped RNA nucleotides link up. Their results indicate that one of two scientists misinterpreted his results. there can be different possible pathways to the same result. the scientists didn’t realize that the experiments were the same but described so differently that they could not see the similarities. the scientists did not know what a RNA polymer looked like since it was a new discovery. Score Quiz