Origin of cells

List the conditions of early earth

• High atmospheric pressure

  Methane and Carbon Dioxide trapping infrared radiation increasing the surface temperature

• UV radiation

  Prevented the ozone layer from forming. Ozone absorbs the damaged UV radiation and protects life on earth. Lack of free oxygen led to UV radiation penetrates to the surface of the earth.

List the steps for Miller-Urey experiment

1. Water is boiled to produce steam, recreating early primordial soup evaporating in the high temperatures that existed on earth

2. Mix the steam with gases (methane, ammonia and hydrogen)

3. Add light impulses such as electrical current to stimulate lightning

4. After a week Miller and Urey found traces of simple organic molecules such as amino acids

Flaws with the Miller Urey experiment

1. Methane availability

   High levels of Methane in the experiment rather than what was in real-life.

2. Energy source

   The experiment used electrical impulses but the real-life would have required some form of UV energy as well

3. Presence of water

   Amino acids tend to be monomers in water than forming proteins.

4. Nucelotides

   Miller and Urey were unable to produce nucleotides in the experiments

Membranes play a role in

cell compartmentalisation to separate the cellular reactions

• amphiphatic nature of vesicles

• Polar part on the outside, non-polar on the inside

RNA is said to be the first presumed genetic material because

1. A system of capable of replication

2. Ability to catalyse chemical reactions

Properties of RNA that suggest it to be

1. RNA can assemble nucleotides spontaneously

2. RNA is able to replicate itself

3. RNA can control rate of reactions, containing ribozymes catalysing peptide bonds

The last universal common ancestor is the

last known organism that is at the bottom of phylogenetic tree of life

LUCA consists of three domains

Eubacteria, Archea, Eukaryote

LUCA has evidence of the three following

• Same biochemistry in all organisms

• Same DNA bases and genetic code shared by organisms

• Same shared amino acids forming protein molecules in organisms