Topic one Flashcards
(56 cards)
How did life arise? and explain each part
1) abiotic earth
2) abiotic synthesis of small organic molecules
- at this point amino acids, nitrogenous bases, and sugars exisited
3) small molecules joined the create macromolecules
- proteins and nucleic acids
4) molecules packed into protocells
5) protocells then created self replicating molecules
-RNA structures started to form
- no DNA strucutues at this time
6)RNA and proteins
7) DNA
8) LUCA
9) evolution into all the different species
what were the two things that helped us understand he synthesis of small organic molecules on early earth
- oparin and haldane
- Miller and urey
what happened during oparin and haldane
- the atmosphere was composed of different compounds that were made from N,H, C, and oxygen
- the environment was believes to be extermly hot with a lack of oxygen
- eventually the atmosphere started to cool down and oceans started to form where all the compounds went to
- the energy sources for these reactions where a result of lightning and UV rays
- it was then believe that these compounds form the modern day monomers for organic molecules (ie. the amino acids, etc.)
what was the early atmosphere composed of
-water vapour
-nitrogen gas (N2)
- Carbon dioxide
- H2
- H2S
- methane
- ammonia
What was the Miller and Urey experiment
this experiment was an experiment that was used to text the oparin-haldane hypothesis where they replicated a similar early atmosphere and exposed the compound to similar energy conditions and heat settings and the organic molecules where created again during this process (experiment had high temperatures and pressure rates as well as a lack of oxygen)
how old is earth
4.6 billion years
when did the first life form appear
3.8 billion years
What was the most important factor of the Oparin and Haldane hypothesis
the early atmosphere was a reducing environment; this helped connect molecules together to form bonds and helped move the electrons around
What was a protocell
a cell that is enclosed in membrane and contains an RNA structure (did translation and transcription) and had its own proteins
What were fossil records used for
they were used to reconstruct history and reveal the changes in the history of life on earth
Which layer are fossil records usually found in
The sedimentary rocks in the layers called the strata
What was the first living organisms
a anerobic prokaryote
Stromatolites
rocks that are formed by the accumulation of sedimentary layers on bacterial mats
What were cynobacteria
an organism that occurs at the same time as plant cells during the endosymbiotic process
How were cyanobacteria important to the great oxidation event
They were able to water and generate oxygen which was leased from the water into the atmosphere which resulted to the oxygen revolution
What was the journey of life
1) no Life
2) anerobic prokaryotes
3) single celled prokaryotes that were anarobic
4) Single celled Eukaryotes
5) the Eukaryotes split into an animal and a plant family
What happened during the photosynthesis and oxygen revolution
The cyanbacteria started to produce oxygen which then interacted with other minerals found in the minerals within the water
What happened following the oxygen revolution
there was an extinction of many prokaryotic groups and some groups adapted a cellular respiration to produce energy
When did the first eukaryotic cells first date back too
1.8 billion years
What is the endosymbiont theory
proposes that the mitochondria and the chloroplast and related membrane organelles where their own prokaryotic cells but now live within a cell
What happens in endosymbiont
- when the cell is drawn up, the cells originally operate on their own but then overtime start to work as a whole to form one single organism
- cell would engulf an aerobic organism therefore making the whole cell aerobic
What is serial endosymbiosis
thought that the mitochondria evolved before the plastids through a sequence of endosymbiotic event
What evidence supported the endosymbiotic theory
- utilizes electron transport enzymes similar to how prokaryotes do this
- these organelles have different DNA (circular plasmids)
- has different ribosomes sizes identical to the prokaryotic ribosomes
what is the origin of multicellularity
the second wave of diversification that gave raise to algae, fungi, and plants
