Lecture 10: Abiogenesis...

Question 1

Abiogenesis

Answer 1

Study of how life could evolve from inorganic matter.

Describes how life could have arose on Earth

Question 2

Abiotic? Biotic?

Answer 2

Abiotic: physical rather than biological, not derived from living organisms.
Biotic: produced or caused by living organisms

Question 3

History of Earth

Answer 3

About 4.5 billion years old
Surface became habitable 3.9 years ago.
Life appeared on Earth 3.5- 39 billion years ago.

Question 4

Elements in Biology

Answer 4

SPONCH: Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon, Hydrogen

Question 5

Early Earth: Atmosphere?

Answer 5

Little oxygen, no oxidation

Early atmosphere was reducing and contained SONCH

Question 6

Urey- Miller Experiment

Answer 6

Recreated hypothetical Earth atmosphere
Subject it to artificial lighting.
Made amino acids, nucleotide bases and energy rich hydrocarbons.
Made molecules similar to the ones found in Titan
Very easy to make adenine.

Question 7

NAD+

Answer 7

Nicotinamide adenine dinucleotide
Found in ALL living cells
Involved in electron transfer
Used to shuttle electrons from Glycolysis and the Citric Acid Cycle to the Electron Transport Chain

Question 8

FAD+

Answer 8

Nicotinamide adenine dinucleotide
Found in ALL living cellsInvolved in electron transfer
Used to shuttle electrons from Citric Acid Cycle to the Electron Transport Chain

Question 9

Organic Soup Model

Answer 9

Early Earth’s reducing atmosphere was exposed to energy through sunlight and lightning.
Producing simple organic compounds or monomers.
These compounds accumulated and concentrated at various locations and localized sources or energy.
Further transportation = more complex organic polymers to develop

Question 10

Which came first? Metabolism? Self Replicating Molecules?

Answer 10

Self Replicating Molecules

Question 11

Which Self Replicating Molecules?

Answer 11

Protein?

Nucleic Acid?

Question 12

RNA World Hypothesis

Answer 12

RNA can store information and catalyze reactions.
What if the reactions you are catalyzing makes more of you?
RNA can bind to substrates and regulate transcription.

Question 13

Phospholipids

Answer 13

Can form structures called Coacervates in water, ABIOTICALLY.
Make up the cell membrane

Question 14

Coacervates

Answer 14

Microscopic sphere of lipid molecules held together by hydrophobic forces from a surrounding liquid.
Can form spontaneously.
Are selectively permeable.

Question 15

Plasma Membrane

Answer 15

Surrounds the cell.
Made of a phospholipid bilayer.
Selectively permeable.

Question 16

First Life on Earth

Answer 16

Only known from fossilized stromatolites: 3.5 billion years old.
Life probably began earlier.

Question 17

Stromatolites

Answer 17

Microorganism collects sediments and deposits it around itself.
After a long time this sediment builds up and forms rock.
Can also be produced ABIOTICALLY.