Chapter 10 Flashcards
Abiogenesis
The study of how life could evolve from inorganic matter. Describes how life could have arose on Earth.
Abiotic
Physical rather than biological; not derived from living organisms.
Biotic
Produced or caused by living organisms.
Life On Earth
Life appeared on Earth 3.5-3.9 billion years ago
Elements in Biology
Sulfur Phosphorous Oxygen Nitrogen Carbon Hydrogen SPONCH
Early Earth
Atmosphere was different
Little oxygen, so atmosphere wasn’t oxidizing.
Reducing and contained sulfur, nitrogen, carbon, and hydrogen.
Only thing needed is phosphorous.
Urey-Miller Experiment
Recreated hypothetical early Earth atmosphere.
Subjected it to artificial lighting.
Make amino acids, nucleotide bases, and energy rich hydrocarbons.
Organic Soup Model
Produced simple organic compounds or monomers.
These compounds accumulated and concentrated at various locations and localized sources of energy.
More complex organic polymers developed.
RNA World Hypothesis
RNA can store information and catalyze reactions.
RNA can regulate transcription.
RNA can bind substrate and direct transcription.
Phosphoilipids
Can form structures called coacervates in water, abiotically.
Make up the cell membrane.
Coacervates
Microscopic sphere of lipid molecules held together by hydrophobic forces from a surrounding liquid.
Can form spontaneously.
Are selectively permeable.
Plasma Membrane
Surrounds the cell.
Made of phospholipid bilayer.
Selectively permeable.
First Life on Earth
Only known from fossilized stromatolites 3.5 billion years ago.
Stromatolites
Microorganism collects sediment and deposits it around itself.
After a long time this sediment builds up and forms rock.
Can also be produced abiotically.
Ecological Questions
Who is where?
Study the distribution of organisms or biodiversity.
What are they doing?
Study nutrient and energy cycling.