Inside the cell + evolution of life #2

Liposomes

Nucleotides + lipids + heat = RNA-like molecules inside liposomes.

Why RNA and not DNA inside liposomes

• can build proteins on its own

• predates protein

• Info usage

Cells are very old

• 3.95 billion yr old rocks contain sediments

Graphite

• sediments contain graphite

• Carbon isotopes provide signatures of life (C12)

• Graphite with higher C12 than normal = organic

Taxonomy

• allows to organize life based on relationships

• bases relationships on evolutionary relatedness

• early tax focused on physical/behavioral similarities

• Carolus Linnaeus (father of modern tax)

• used 2 before now 5 kingdoms

Phylogeny as the basis of taxonomy

• Phylogenetic trees show relationships between organisms

• organisms cluster into groups

• groups cluster into larger groups

• more recent common ancestor = more closely related

Determining common ancestry

• relies on sequence data

What is a taxon

• A named group

• plural = Taxa

Domain

• broadest taxon

What are the 3 domains

• Bacteria

• Archaea

• Eukarya

Phylum

• A major lineage within a domain

• Plural = phyla

How is naming performed

• each group is broken down into narrower groups

• organisms are named by genus & species

Genus

Closely related group of species

Species

Individuals that regularly interbreed

what do all cells have?

• Proteins

• Nucleic acids

• carbohydrates

• plasma membrane

What is the difference between Prokaryotes and Eukaryotes?

Prokaryotes

• Pro = before

• Karyote = Kernel

• No nucleus

Eukaryotes

• Eu = true

• Karyote = Kernel

• Have nucleus

Bacteria

• domain of prokaryotes

• most unicellular

• cell wall (peptidoglycan)

• 1 kind of RNA polymerase

Archaea

• Domain of prokaryotes

• unicellular

• cell wall

• 3 kinds of RNA polymerase

Eukaryotes

• Many multicellular

• cell wall (cellulose Chitin)

• several kinds of RNA polymerase

• diverse

Prokaryotic CELLS

• One main circular chromosome, hangs out in nucleoid

• plasmids

• Ribosomes

• photosynthetic membrane

• cell wall

• flagella

Eukaryotic CELLS

• More complex

• many chromosomes

• DNA stored in nucleus

• larger than prokaryote cells

• membrane bound organelles

What is the benefit of compartmentalizing?

• specialization

• separation of incompatible rxns

• efficiency high

Key differences between the prokaryotic and eukaryotic cells?

• size

• genetic material

• compartents