Bio 101 Day 10

Bio 101 Day 10 - The Origin and Evolutionary History of...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: The Origin and Evolutionary History of Life Chapter 21 Geologists believe that ancient earth provided the exact conditions necessary for chemical evolution-little or no free O2 (reducing conditions necessary to prevent oxidation of organic molecules, the building blocks of life)-Presence of chemical building blocks (water, minerals, gases)-Time to allow resulting accumulation and interaction and formation of organic molecules Chemical Evolution-Prebiotic soup hypothesis-organic molecules formed near Earths surface in a prebiotic soup of inorganic building blocks. Polymerization occurred spontaneously from monomers on hot rock or clay surfaces-I ron-sulfur world hypothesis-Polymerization of organic molecules produced at hydrothermal vents in deep ocean floor-Vents acted as products of energy-rich food including H-S and Methane Miller and Ureys Experiment Could organic molecules form in a reducing atmosphere (early earth)? Gases in flask react; in one week a variety of simple organic compoundsamino acids, purines, pyrimidines etc accumulate-First step in the origin of life The Origin of Cells-Macromolecules-Polymerization from small organic molecules-Protobionts-Macromolecular Assemblages-A-biotically formed-Exhibit many functional and structural attributes of living cells, homeostasis, catalytic activity, etc.-Cells-Then arose from protobionts-Enclosed the information necessary for self-replication Microspheres-Protobiont is a form when water is added to abiotically formed polypeptides (liposomes when lipids present); selectively permeable; able to control osmotic swelling and shrinking; maintain homeostasis, and an electrical potential across surfaces RNA World Model-RNA as the first informational molecule to evolve-Self replicating and enzymatic molecule capable of catalyzing a number of biologically important reactions-Progression toward self-replication cell-Ribozyme (ribosome)-RNA makes a double stranded copy of itself-Evolution into DNA-Information transfer advantageous (DNA less reaction than RNA)-Natural selection of molecular level-resulted information sequence-DNA (non-catalytic) RNA Protein RNA Molecules Q. Can in vitro natural selection result in chemical evolution of catalysts, and could these...
View Full Document

This note was uploaded on 04/06/2010 for the course BIO 01-119-10 taught by Professor D'arville during the Fall '09 term at Rutgers.

Page1 / 10

Bio 101 Day 10 - The Origin and Evolutionary History of...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online