Origins of Life

Question 1

Four Steps of Chemical Evolution (each requiring energy-input):

Answer 1

1. Production of small molecules (containing reduced carbon)
2. Creation of a prebiotic soup (of amino acids, sugars, lipids, and nitrogenous bases…)
3. linkage of these organic subunits to make the large organic molecules important in cells today…
4. evolution of a self-replicating molecule

Question 2

Earth at the time of life’s origin:

Answer 2

reducing atmosphere (i.e. no oxygen) and high energy (uv energy, lighting, and heat from earth)
result: small molecules (monomers) essential to living systems form and polymerize

Question 3

Polymerization reactions

Answer 3

generate carbohydrates, lipids, amino acids, and nucleic acids
molecules accumulated and concentrated

Question 4

Protobionts

Answer 4

aggregation of polymers…living cell precursors
The earliest protobionts probably had lipid-based membranes