Definition of life Order: cellular structure Crystals have structure without life

reproduction Growth & development

Energy utilization Response to the environment

Evolution Darwin

Adaptation

Darwinian theory of evolution Over production Individual variations

Natural selection 75% of population perished in one storm predators prey

Artificial selection

Composition of cells Organic molecules: Carbon is a versatile chemical element Water & oxygen

Difficulties with other elements Weak bonds No double bonds

Molecular components Carbohydrates: 2H/O sugar, starch, cellelus. glucos C6H12O6 Lipids: fatty acid Store energy for cells Proteins: large molecules Nucleic acids: DNA (deoxyribonucleic acid) & RNA (ribonucleic acid) Store structural information Built on amino acids. Enzymes & catalysts Regulate reaction rates Build structures Provide energy to cells fibers

Two basic cell types Prokaryotic cells: No distinct nucleus Single cell species eg E coli or Salmonelia Eukaryotic cells: Both single cell (amkebas) complex species (plants, animals)

Biological tree of life: five kingdoms Based on cell structures Drawin’s notes

RNA tree of life: three domains Based on molecular structure

The chemistry of life Metabolism: chemistry of life regulates reaction rates Atp(adenosine triphosphate) Metastable reaction +H 2 O

Carbon and energy Heterotroph: get carbon from other organic compounds Autotroph: get carbon directly from the atmosphere Photosynthesis: sun light provides a source of energy, CO 2 Chemoheterotroph: organic molecules Chemoautotroph: inorganic chemicals, eg sulfur, iron, amonia. CO 2 Carbon is the most common raw material

Importance of water 1)Dissolving organic molecules 2) transportation 3) ATP chemistry

Double helix of DNA molecules

Gene’s analysis

DNA replication

Genetic code

Virus (a strand of RNA, not alive) Coronavirus: common cold, SARS

Mutation and evolution

extremofiles Thermofiles