{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Biology Exam #2 Notes

Biology Exam #2 Notes - Biology Exam#2 Notes Lecture#1...

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

View Full Document Right Arrow Icon
Biology Exam #2 Notes Lecture #1: Keywords: Earth formed 4.6 billion years ago, reducing atmosphere, abiotic synthesis, Oparin-Haldane, Miller-Urey,  prebiotic soup, ribozyme, RNA world, autotroph/heterotrophy, endosymbiosis, homology, homoplasy, taxon,  taxonomy, systematic, phylogeny, cladistics, clade, parsimony, synapomorphy, plesiomorphy, monophyletic,  paraphyletic, Linnaeus, Kingdom to Species, binomial, three domains. Virus genome, cpsid, bacteriophage.  Archaea [halophile, thermophile, methanogens], peptidoglycan: Gram positive, lipopolysaccharide is Gram  negative, cynobacteria, heterocysts, nitrogen fixation, chlorophyll A, plastid. Lecture: Origin of life Kingdoms Viruses and prokaryotes Conditions on early life     o Earth is ~4.6 billion years    FOSSILS o Atmosphere had little free oxygen Included carbon dioxide, water, carbon monoxide, hydrogen, nitrogen Maybe also NH 3 , H 2 S, CH 4 o REDUCING atmosphere Nothing rusts, not a lot of oxygen Life could never evolve Requirements for chemical evolution to produce life o Absence of oxygen -> why? Oxidation destroys organics -> therefore, reducing atmosphere o Energy -> what kind? What for?? Covalent bonds o Chemical “building blocks” -> what kind? Where from?
Image of page 1

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

View Full Document Right Arrow Icon
Amino acids, etc. o Sufficient time Prebiotic soup hypothesis     o Ocean   lightning was energy form for spontaneous life Molecules formed near surface o Oparin & Haldane hypothesis Abiotic synthesis using steam, sparks, water, ammonia, hydrogen, and methane Miller & Urey : experimentally demonstrated that amino acids can be made  abiotically o Abiotically – made without life; made spontaneously; ie. With lightning Miller & Urey abiotic synthesis of monomers 13 amino acids, glycine was the most None formed in oxygen was added By adding HCN   make nucleotide base adenine and other bases abiotically o Ocean fills with all of these things (ie. The soup) o Sugars, nucleotides, amino acids form spontaneously Iron-Sulfur World hypothesis     o Organic molecules formed at hydrothermal vents on the ocean floor o Lab simulations show catalyst effects of iron and nickel sulfides Requirements for evolution: hereditary material     o RNA world – why not DNA? Self-replicating RNA molecules Function as both enzymes and substrate for replication Ribozyme is enzymatic RNA
Image of page 2
First step in evolution of the DNA/RNA/protein system o In RNA world, ribozymes catalyzed protein cells The First Cells     o Heterotrophs that feed on organic molecules Do not need to make own food because there is so much in ocean (soup) o Anaerobic
Image of page 3

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

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern