ORGINS OF LIFE Flashcards
How old is Earth
4.5 billion years
How old is life on Earth
3.7 billion years
How old is photosynthesis
3.2-3.5 billion years
Explain why the discovery of ribozymes was so important for understanding the first living thing
The discovery of ribozymes changed the way biologists viewed life. The discovery of ribozymes told us that RNA can posses both a genotype and phenotype
Describe the evidence from extant cells that RNA has an ancient origin
RNA’s three roles serve as evidence for its ancient origin. The existence of catalytic RNA, Metabolism & Replication, ribosome’s role in protein synthesis, and biological currency; ATP of GTP.
Life on Earth began with a simple RNA molecule that can copy itself.
RNA World Hypothesis
What evidence is in favor of the RNA World Hypothesis
(RNA is) Ribosomes are ribozymes
The most recent common ancestor of all extant organisms is known as the Last Universal Common Ancestor. It is also known as the cenancestor.
LUCA
the Initial Darwinian Ancestor
IDA
How are LUCA and IDA different?
IDA began the diversity of descendant lineages. LUCA is the common ancestor of all extant organisms
What are some advantages of becoming cellular, and how might this have happened?
Advantages:
Compartmentalization
Link of Genotype & Phenotype
Universal Genetic Code
How:
Microspheres are formed when polyamino acids are in water or salt.
Tiny compartments in mineral deposits.
Where did the original components of RNA potentially come from? (know 2 models)
Oparin-Haldane; the ingredients were here on Earth already. Bolide impact; the ingredients came along with some kind of impactor like a meteorite.
What are the steps in creating cellular life from RNA? For which of these steps do we still lack some evidence?
Oparin-Haldane Model:
If you have all the forms to create RNA then RNA will continue to build until it builds a shape and continues to replicate or until it forms a ribozyme then it will aggregate to form cellular life
Lack of Evidence:
The membrane forming step.
