Origin and Diversity of Life🦧

Created by

Kinley wangmo

Cards (121)

Primitive Earth was reducing type and present Earth is oxidising type
High temperature, lightning and intense UV rays provided energy required for chemical reactions
Three stages of origin of life
Chemogeny
Biotic origin of life
Cognogeny
What is the process of transformation of the nonliving into living organisms called? 
Origin of life
How long ago did Lederberg consider the origin of life to have occurred?
About one billion years or more
What are the three stages in the origin of life according to Lederberg?
Chemogeny, biotic origin of life and
What does chemogeny refer to? 
Chemical origin of life
What was the composition of Earth's atmosphere about 4 billion years ago?
Ammonia, methane, and water vapor
What was absent in the primitive sea that affected biological reactions?
Enzymes
How did the absence of enzymes in the primitive sea affect the synthesis of compounds?
Reactions occurred at a much slower pace
What are some examples of simple organic compounds formed during chemogeny?
Alcohols, aldehydes, glycerol, fatty acids, amino acids, sugars, nitrogenous bases
What processes led to the formation of complex organic compounds from simple organic molecules?
Condensation, polymerization, and chance chemical reactions
What are some examples of complex organic compounds formed during chemogeny? 
Polysaccharides, fats, proteins, nitogenous bases, nucleosides, nucleotides
What is the significance of Stanley Miller and Urey's experiment?
It provided proof for the formation of simple organic compounds
What does abiotic synthesis of macromolecules refer to?
The formation of macromolecules from nonliving chemical processes
How do enzymes affect biological reactions in living organisms?
They speed up biological reactions
What does it imply that nature could synthesize all compounds known to exist in present-day living beings?
It suggests that all necessary compounds for life can be formed through natural processes
Cognogeny - evolutionary development of living beings through natural selection
Early bacteria had no nucleus or membrane-bound organelles
What does the term "prebiotic soup" refer to in the context of the origin of life?
It refers to the hot dilute soup from which life arose, containing organic substances.
How did Haldane describe the sea in relation to the origin of life?
He described it as the hot dilute soup or prebiotic soup from which life arose.
What processes are believed to have occurred in the sea to synthesize complex organic substances?
Condensation and polymerisation.
According to the rule of thermodynamics, what happens to organic molecules in solution?
They cannot accumulate in large numbers because they break up as fast as they are built up.
What implication does the presence of organic substances in sea water have for processes occurring in space?
It indicates that similar processes are also occurring in space on other planets.
What does NH3 stand for in the context of organic chemistry?
Ammonia
What are coacervates?
Colloidal aggregates of macromolecules formed in prebiotic conditions
Who proposed the concept of coacervates?
Oparin and Sydney Fox
How did Oparin obtain coacervates? 
By heating a mixture of protein and polysaccharide and shaking the solution
What temperature range did Sydney Fox use to obtain protenoid microspheres?
130° to 180°C
What role did the fat molecules play in the formation of coacervates? 
They formed a membrane-like coating around each aggregate
What was the significance of the membrane-bound aggregates in coacervates? 
They held molecules closer together, increasing chances of chemical reactions
How did coacervates grow in size?
By absorbing molecules from their environment
What types of reactions started in the coacervates?
Breakdown and building up reactions
How did proteins in certain coacervates enhance their efficiency?
By acting as enzymes, facilitating chemical reactions
What was the presumed first abiotic structure at the margin of nonliving and living things? 
Coacervates with proteins acting as enzymes and ATP as a source of energy
How did the reactions in coacervates occur compared to those in hot dilute soup?
They were comparatively faster
What are the large spherical aggregates formed by complex organic molecules called? 
Coacervates or microspheres
What phenomenon was observed in some microspheres obtained by Sydney Fox?
Some microspheres showed budding
What led to natural selection among coacervates?
Coacervates with a more rapid rate of replication became more numerous
Endosymbiosis theory proposes that mitochondria and chloroplasts originated as free-living prokaryotes that became incorporated into larger host cells.