Domains of Life an Cellular Diversity

Cell Theory

All living organisms are composed of cells

Cells are the basic building blocks of life

All cells come from pre-existing cells

Organism

An individual form of life

Single-celled organism = Unicellular

Organism made up of many cells = Multi cellular organism

Characteristics of life

Response

Reproduction

Growth and development

Regulation

Homeostasis

Energy processing

Order - organisation and structure

Three basic cell types on earth

Eukaryotes

Bacteria

Archaea

Bacteria and achaea are Prokaryotes

Prokaryotes

Lack of membrane- bound organelles

Presence of a single, circular chromosome

Tree of life = A visual representation of the suggestion evolutionary history of organisms classified using particular characteristics

Phylogeny = Evolutionary relationship of organisms through time

Single lipid layer membrane and membranes do not contain the same lipids that other organisms do - they have Isoprene chains

Isoprene chain = glycerol linked to a hydrocarbon chain by esther linkages

Cell wall not made of peptidoglycan. Most have S layer - protein subunits.

Like Bacteria - Archaea have 70s ribosomes but a different shape
They have more complex RNA polymerases than Bacteria
Lack membrane bound organelles
Lack Nucleus