Origin Of Life Quiz Flashcards
Formation of simple molecules
-3.8 billion years ago
-CH4 (Methane)
-NH3 (Ammonia)
-H2O (Water)
-H2 (Hydrogen gas)
-These molecules were abundant in Earths early atmosphere
The Formation of simple organic molecules
-3.6 billion years ago
-Energy from volcanoes, lightening, and UV radiation helped form
-Amino acids (building blocks of proteins)
-Nucleotides (building blocks of RNA and DNA)
Formation of complex molecules
-3.6 billion years ago
What helped?
-DNA=Carries genetic information
-RNA=First genetic material (RNA world hypothesis)
-Proteins=Important molecules coded by DNA
-Lipids (Fats)=Help form membranes that create barriers for cells ex
Formation of “proto-cells”
-3.5 billion years ago
-Lipid closed up molecules, creating isolated environments.
-These structures could maintain a internal chemical balance
Self replication and metabolism
-3.5 billion years ago
How it happened?
-DNA Replication=Allowed genetic inheritance
-Cell Division=Primitive Reproduction
-Metabolism=Used molecules for energy.
Transition to “True Cells”
-3.4 billion years ago
-First prokaryotic cells (bacteria-like, simple, unicellular)
-Capable of independent survival and reproduction
Why did the ocean play a big role in the origin of life?
It acted as natural solvent, water let molecules react which made structures like nucleotides and amino acids. Also was more suitable environment than land
What molecules started life?
Amino acids, nucleotides
What about water was important?
It’s high specific heat, it is polar, and cohesion. Also it is less dense as solid than as liquid which made ice at surface so life could survive in liquid below.
What did early cell membranes build?
Polarity allowed them to build Hydrophobic barrier which let only important molecules pass through
What did cohesion do?
Allowed early organisms to float so they could interact with eachother.
Also played role in water transport so early membranes could form organized structures.
When did life begin?
3.8 billion years ago, planet was harsh but ocean was good environment
When did life begin?
3.8 billion years ago, planet was harsh but ocean was good environment
