SCNC M4 L2

what is central dogma?

DNA (gene instruction for life) transcript into RNA (regulation and expression of DNA) and RNA are translated into protein.

in some special cases, RNA will self replicare and even reverse transcripted into DNA

What are the key life molecules?

Proteins, Carbohydrates, Nucleic acids, Lipids

Who is life created?

1. having right elements (CHONSP)

2. Mixed together using water

3. supply with energy

4. favourable condition

what should be the 1st type of life characteristic?

able to replicate,assemble into complex structures having basic funtions

what is the top 10 mot abundant elements in the human body?

Oxygen

How is the lifecompound formed?

1. Having the required elements (water, ammonia)

2. energy (lightning, sparks)

This forms amino acids, which can further combine into a polymer protein

Why the miller & Urey’s experiment is still not enough to explain how the first cell is formed?

Even though it proves that raw building blocks + energy formed life molecules, but how life mocules formed cell is still mystery

Other than life forming on earth, what are the other possible origin of life ?

On the asteriod, there are still some life molecules, so maybe the life molecules from spaces recombine into cells on earh

when did the life beign?

First DNA/protein and last universal common ancestor is about 3.6biliion years ago

what is the state of the Earth at the early stage?

it is called Haden Eon
Lots of meteorite impact
Molten
atmosphere is stripped away by solar wind but got replenished by volcanic eruption

How is the stable hydrosphere of the earh formed?

Earth cooled down, the water vapour condensed into ocean

What are the possible first molecule of life during the period between pre-biotic chemistry and early life?

RNA
It can act as Ribozyme that splice other RNA protein to help transforming it into protein

It can also fold intoDNA

This is known as RNA world

what are the other alternatives of RNA world?

1. metabolism first

2. membrance first

3. protein first

4. Iorn-sulfur

5. Lipid

what is the difference between RNA first and metabolism first?

RNA: Form RNa first and it can give protein what catalyst yhe chemical reacitons (emphasis on randomness)

metabolism: hydrothermal vents makes metabolism possile and create lots of energy that help the formation of the self-replicating RNA through multiple rounds (emphasis on environment)

what are some evidence for age of origin of life?

Finding when are some lifes present
stromatolies which are layers of calcium carbonate formed by photosynthetic bacteria, this shows the olderest know fossils of life.

Microbialite, deposite made by the mediaiton of microbes, showing that at ancient times, mircobes are already present.

Cyanobacteria

Carbon isotoeps ratio

However, older known doesn’t mean earliest, as there might be some more simpleir lifes

Other than finding when lifes emerges, what are the alternative way of getting to the origin of life?

directly reconstruct the Latest universal common ancestor geomone

This shows that LUCA might be an anaerobic autotrph that uses no oxygen, but chemical substance from the hydro vents (thermophile) to produces complex organic compounds