Week 2 Flashcards
What are the four basic organic compounds?
H, O, C, N
Which are the trace metals?
V, Cr, Mn, Co, Mo, Fe, Ni, Cu, Zn
Which are the trace non-metals
Se, I, B, Si, F
Why Clay and Sulfides are very important for the evolution of life on Earth?
- Because they are the source of many elements
- Soil is mainly composed of iron silicates, of Mg and Al
- Tey contain pockets and this is important for bringing in different chemicals together
- They are from both chemical and physical equilibrium.
What are universal organic chemicals?
Organic chemicals that can form in absence of life (They are found also in Interstellar Ices) and they were presents in early earth.
Which elements did Urey and Miller put together?
Ammonia (NH3), mETHANE (ch4), Water and Hydrogen.
Describe the Urey-Miller experiment:
They elaborated a flask apparatus, zapped electricity in it to stimulate the formation of molecules and in it they synthetized 22 amino-acids and hydrocarbons.
What molecules were synthetized in the Urey-Miller experiment?
- All fives bases presents in both DNA and RNA
- 17 of the amino-acids used in protein synthesis
- 3- and 6- carbon sugars (But not the 5-)
Elencate the properties of water:
- Excellent inorganic solvent
- Temperature buffer
- Metabolite in many reactions
- It’s an environment where organism can leave
- It’s a very small molecule
What is a metabolite?
Is a chemical involvev in metabolism
Elencate the chemical structure of a molecule of water?
Water is polar and it’s bent (it has an angles of 104.3°) and this form a dipole.
Why water is polar?
Because electron are shared unequally and electronegativity is different from H to O.
What are hydrophilic substances?
Ionic and polar substances that dissolves in water due to their polarity.
What are hydrogen bonds?
A covalent bond between hydrogen in water and a more electronegative atom creates a polaryzed bond.
Is hydrogen bond weak?
Individually it’s weak but collectively it’s strong.
What are the properties of hydrogen bonds?
- Hydrogen atoms are shared between to electronegatives atoms
- Bonds tend to be linear
What are hydrophobic substances?
Non polar substances are insoluble in water, but water molecules are attracted by each other so hydrophobic compounds are excluded by water.
Why is important for hydrocarbons to be non-polar?
Becauste they are non polar which means they’re hydrophobic and so water tend to isolate them and put them together and interact.
What happens to a non-polar solid in water?
It doesn’t dissolve (hydrophobic effect)
What happens to a non-polar liquid in water?
It forms two layer (oil-water) (hydrophobic effect)
What are the 3 abilities of life?
Ability to acquire energy, Ability to use that energy to grow and replicate and the ability to evolve.
When did life appeared on our planet?
3.9 Ga
Why was mitocondria invented?
Because oxygen was toxic for life at first since it strip electronf from carbon based substances and all those molecules life used to produce energy.
In which environment could the chemical evolution have occured?
- In water droplets on the surface of clay
- In hydrothermal vents
- In hot pools at the edge of the ocean
Why Carbon is so important for life?
Because it’s a stable molecule in its outer shell that allows it to make 4 bonds in 4 different directions creating tetrahedral structures.
What were the things you need to create life?
Water, Nitrogen, Carbon, Fosforus but also energy
Which kind of energy helped the creation of life?
Geothermical energy
What could have enhanced prebiotic metabolism?
Localised concentration of chemical reactants
Why can RNA replicates itself in some conditions?
It’s autocatalytic
What are the conditions that led to the presence of life on Earth?
Earth cooled down so water became liquid and oceans formed. Chemicals from the crust dissolved in water and this led to the formation of simple molecules
Why scientist think that life could have originated on the surface of clay?
Because clays contains silicates that may have catalyzed condensation reactions
Why scientist think that life could have originated on hydrothermal vents?
Because Fe-Ni may have catalyzed the polymerization of amino-acids in absence of Oxygen.
Why scientist think that life could have originated in hot pools at the edge of the ocean (primordial soup theory)?
Because evaporation may have concentrated monomers favoriting polymerization
What’s a key point of the appearence of life on Earth and why?
The appearence of a catalyst to speed up biochemical conversion
What are rybozimes?
Catalytic RNAs
What were the two roles of RNA at the beginning?
- Informational
- Catalytic
Discuss the 5 point of RNA World Theory
- Ribose, bases and phospate formed RNA
- Some RNA gain the ability to self-replicate
- RNA started making catalytic proteins
- The presence of catalytics proteins increase the efficiency of RNA replication and this led to the formation of double stranded RNA
- Double Stranded RNA evolved in DNA which became the primary information storage molecule
Discuss the property of a protocell
- Act as an organized system of parts
- Interior is disntict form the exterior environment
- Capable of self-replication
