BIOL 215 Study Guide - Final Guide: Osmotic Shock, Chloroplast, Archaea
1. Review 215
90% of mutations are deleterious
you want a diverse genetic variation – humans selectively breeding makes it
easier for disease – potato famine
not all variability come from mutations – interbreeding
epigenetics – your genes can lead to different phenotypes, so selection can
act on those genes
ORIGIN OF LIFE
- origin of elements on earth
- primitive earth`s atmosphere and ocean
* big bang 10-15 bya
* formation of earth fe, mg, si, o
*early atmosphere – high reducing co2, n2, h2o
1. traces of h2, s, nh3, ch4 (hydrogen, sulfur gas, ammonia)
*anoxia prevents buildup of organic molecules
HOW DID IT FORM? 80% from volcanoes, 20% from impact bodies
*PRIMITIVE OCEAN – earth started cooling at 4 bya ish
ocean dissolved gases – erosion of rocks = salt
-stromatolites 3.5bya are associated to oxygenation of planet
-biomarker evidence for life at 3.85 bya
how can we use rocks to date things?
-until we have aminoacids we cant have life. Mention two hypothesis on
how we got the building blocks (miller-urey and panspermia?)
MILLER- UREY (ancient gases+spark in a lab, 17 out of 20 basal aminoacids
plus all nucleotides)
- panspermia
Murchison meteorite
find more resources at oneclass.com
find more resources at oneclass.com
ALH84001 Mars meteorite with what looks like fossilized cells
Infrared spectrometry (HOW)
- origin of building blocks
- rna world (why was it RNA first? Single strand?... but didn’t they bind
double strand in crepe model?)
- why is carbon so important to life?
- crepe model (clay, adenines bind to the template, clay is positively
charged and iron pyrite is a catalyst. Once aminoacids build up, their
negative charge allows the complementary aminoacids to bind.
- ribozyme – why the RNA world was the first step. RNA has enzymatic
properties; stores and catalyzes
protein-like – catalyzes other reactions
- from RNA world to cells – compartmentalization (osmotic stress and
electrochemical gradient), metabolism, deep sea vents (rich in metal and
high temperatures)
- compartmentalization came before the advantages of
metabolism.
- when cells divide they can pass their envelope to new
nucleic acids
- primitive organisms
name the requirements of life?
-liquid water
-energy source
-elements for the essential biomolecules
- what are the unique properties of water?
Surface tension, 50-90% body mass, high heat capacity, all chemical
reactions necessary for life occur in water, universal solvent
Energy is used for motility, breaking down resources
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
* formation of earth fe, mg, si, o. *early atmosphere high reducing co2, n2, h2o: traces of h2, s, nh3, ch4 (hydrogen, sulfur gas, ammonia) *primitive ocean earth started cooling at 4 bya ish ocean dissolved gases erosion of rocks = salt. Stromatolites 3. 5bya are associated to oxygenation of planet. Until we have aminoacids we cant have life. Mention two hypothesis on how we got the building blocks (miller-urey and panspermia?) Miller- urey (ancient gases+spark in a lab, 17 out of 20 basal aminoacids plus all nucleotides) Alh84001 mars meteorite with what looks like fossilized cells. Single strand? but didn"t they bind double strand in crepe model?) Crepe model (clay, adenines bind to the template, clay is positively charged and iron pyrite is a catalyst. Once aminoacids build up, their negative charge allows the complementary aminoacids to bind. Ribozyme why the rna world was the first step. Rna has enzymatic properties; stores and catalyzes protein-like catalyzes other reactions.
