Second Step of The Theory of The Origin of Life - ✔️✔️2) Joining of small molecules into
macromolecules such as proteins and
nucleic acids
Third Step of The Theory of The Origin of Life - ✔️✔️3) Packing of these macromolecules
into protocells (droplets with
membranes than maintained an internal chemistry separate from that
of their surroundings)
Vesicles, often have phospholipid bilayer
Fourth Step of The Theory of The Origin of Life - ✔️✔️4) Origin of self-replicating
molecules that eventually made inheritance possible
Possible Abiotic Sources of Life (1st Step of Origin of Life) - ✔️✔️Ultraviolet Energy and
Sparks could be energy source for miller-urey
Other possible origins, hydrothermal vents deep in the sea floor, volcanic, minerals
coming from black smokers. Reduction of minerals to gain + hear = energy
Life came from else where, meteorite. The billion year gap two short, therefore amino
acids came from meteorite, outer space. Meterorites brung necessary organics.
Step 2: Macromolecule Synthesis - ✔️✔️Monomer, to polymer via dehydration reaction.
Reverse, splitting into monomers is hydrolysis
Dehydration reaction results in water and linkage, likewise adding water will split a
polymer (hydro "lysis" split)
Step 3: Protocells/Protobiont - ✔️✔️• Vesicles can form spontaneously when hydrophobic
lipids organize into a layer and produce fluid-filled enclosed compartments
• Enclosed compartments maintain chemistry different from the surroundings
• Vesicles can divide on their own
• Early vesicles would have needed to contain self-replicating molecules and
have been capable of metabolism
Step 4: Self-replication - ✔️✔️• RNA was likely the first genetic material as it is simpler
than DNA and can act
as a template for DNA
• RNA can self replicate
• RNA is essential for protein synthesis and can act as a catalyst (ribosomes)
Primary Endosymbiosis - ✔️✔️The engulfment of a mitochondria by a larger eukaryotic
cell that gave rise to the first cellular respiration eukaryotes with mitochondria.
The engulfment of a cyanobacterium by a larger eukaryotic cell that gave rise to the first
photosynthetic eukaryotes with chloroplasts.
Mitochondrial Organelle - ✔️✔️• Involved early eukaryotic cell and aerobic alpha
proteobacterium (Bacteria
domain)
• Phagocytosis by eukaryotic cell; proteobacterium lived in symbiosis with
eukaryotic bacteria
• The "host" cell received energy made by engulfed proteobacterium while the
proteobacterium received some other essential metabolites
• Over time, the host and proteobacterium became interdependent until the
proteobacterium was reduced to an organelle
• Many mitochondria specific protein genes were moved into nucleus of host and
• mtDNA is similar to DNA found across major domains
• Mitochondrial membranes very similar to free living alpha proteobacterium
Eventually loses a membrane, step 3 and becomes integrated properly
Chloroplast Organelle - ✔️✔️• Involved photosynthetic bacteria and a non photosynthetic
(heterotrophic)
eukaryote
• Phagocytosis by heterotrophic bacteria; cyanobacteria lived in symbiosis with
eukaryotic bacteria
• The "host" cell received a proportion of sugars made by engulfed cyanobacteria
while the cyanobacteria received some other essential metabolites
• Over time, the host and cyanobacteria became interdependent until the
cyanobacteria was reduced to an organelle
• Most genes for photosynthesis were moved into nucleus of host and chloroplast
organelle retain just a few just like mitochondria
• The mechanism of gene transfer from the endosymbiont to the host is unclear
• Genes remaining in chloroplast are similar to those in cyanobacteria
Nucleomorph - ✔️✔️Proof of Secondary Endosymbiosis (when another eukaryote comes
along and engulfs the multicellular organism), Nucleomorph represents the nucleus of
the other Eukaryote, that becomes tiny over evolution. The additional membrane is
evidence of it as well.
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