IB Biology - A2.1 - Origins of Cells

Qualities of living things

self-sustaining, passing of genetic information, use energy, divide

Requirements for the origin of cells

catalysis, self-assembly, compartmentalization, self-replication

Miller-Urey Experiment

Experiment that found that organic molecules can form in a strongly reducing atmosphere.

The first genetic material on Earth was probably ________.

RNA

Properties of RNA

Can store genetic information, is self replicating, and can act as a catalyst

L.U.C.A

last universal common ancestor

Evidence for LUCA

All Living Things share
1) "Right-handed" spiral DNA double helix
2) Universal genetic code (A T C G codes for specific amino acids)
3) Same order of DNA -> RNA -> Protein; DNA is transcribed into RNA which is then translated into Proteins
4) All living things have ~400 genes in common

hydrothermal vents

spots on the ocean floor where hot gases and minerals escape from earth's interior into the water

Evidence to support LUCA evolved near hydrothermal vents

alkaline environment, high temps, high concentrations of hydrogen, methane, ammonia, carbon dioxide, and sulfides

Polymerization

a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.

Why fatty acids were likely the primary component of the membrane of early cells

fatty acids are structurally much simpler than phospholipids and may have formed more readily in a prebiotic environment