A2.1 Origin of Cells

Cell theory

Cells are the basic units of life, all organisms are made of at least one cell, all cells come from preexisting cells

Functions of life

1+ cell, metabolism, homeostasis, stimuli, reproduce, grow, genetic info

Viruses

Non-living organisms; does not possess all of features of life

Catalysis

Speeding up chemical reactions

Self-replication

Able to copy itself by itself

Self-assembly

Forming organized structures

Compartmentalization

Creating cell-like membranes

Cell membranes

Made of phospholipid bilayers

Phospholipids

Made of hydrophilic heads and hydrophobic tails

Amphipathic

Molecule with both hydrophilic and hydrophobic parts

Membrane

Thin, separating layer 

Vesicle

Small bubbles with a membrane

Enzyme

Complex protein that speeds up chemical reactions

RNA

Less complex molecule, an enzyme able to store genetic info and self-replicate

RNA

Forms peptide bonds, stores genetic code and is an enzyme

LUCA

Last Universal Common Ancestor

LUCA

Most recent common ancestor that all organisms share

LUCA evidence

All organisms have a universal genetic code, cellular structure, and shared genes

Endosymbiosis theory

Eukaryotes came when LUCA-descendants became mitrochondria or chloroplast

Natural selection

LUCA is anaerobic, genetic system, protein synthesized, and used ATP

4B+

LUCA age

Hydrothermal vents

Aqueous environments able to do reactions, had less compounds, and potential catalysts

Radioactive dating

Method used to determine ages of materials like rocks and fossils by measuring the decay of unstable radio isotopes

Half-life

Time taken for isotopes to decay half its initial value

Early-life

Fossil evidence near hydrothermal vemts

3.77B

Oldest fossil age

Genetic evidence in vents

Genes and proteins adapted to anaerobic, metal-rich, and chemically reactive conditions