Origin of Life Flashcards
What are 2 hypotheses on how life originated? Which one has more evidence?
Abiogenesis (more evidence)
Panspermia (no evidence)
What is an abiotic?
A non-living thing
What is abiogenesis?
The natural process by which life evolved from non-living matter
The transition from non-living to living entities was a _______ and ______ process
complex, gradual
Abiogenesis assumes primitive earth contained ________ precursors that could be synthesized into complex organic compounds
inorganic
Organic compounds must contain what?
Carbon and hydrogen carbon bonds
Inorganic compounds that could lead to organic compounds include what?
Nitrogen, ammonia, carbon dioxide, methane, etc
Some conditions on primitive earth that allowed organic compounds to be created include…
- Atmosphere with vapour, nitrogen, CO2, ammonia, etc
- No O2
- Frequent lightning and UV radiation
What 1950’s experiment demonstrated abiogenesis?
Miller-Urey chemical experiment
Describe the method and results of the Miller-Urey chemical experiment
Method: Water vapour was sent to a flask containing methane, ammonia, and hydrogen. Electrical sparks were also fired to simulate lightning.
Result: The cooled water vapour contained organic compounds like amino acids.
Experiments similar to the Miller-Urey chemical experiment have shown formations of other organic ___________, like RNA, carbs, and lipids
macromolecules
Cell membranes are composed of _______
lipids
Lipids have a hydrophilic polar and and hydrophobic non-polar end. Describe how these join to form a lipid bilayer
The polar ends face the interior and exterior of the cell. The non-polar ends remain within the centre of the membrane.
Describe the main structures phospholipids can form
Liposomes: Donut sphere
Micelle: Timbit
Bilayer sheet: Rectangle
Regarding phospholipid structures, ________ are essential components of primitive cells. Why?
liposomes. The structure allowed nucleic acids and other polar compounds to become internalized.
