Packet #3

Properties I All living things are parts of larger systems of matter and energy and matter continually recycles through systems as energy flows through the systems Life & Cells Obey Physical/Chemical Laws of the Universe All living things are parts of larger systems of matter and energy Matter is continually recycled through systems as energy flows through There is no unique law defining the living state separate from different natural/physical laws* Cells extract energy Transform energy Capturing light Redox reactions Electron flow Expend energy to maintain an ordered state

Properties II All living things maintain a high degree of order and complexity The cell Size of cells may vary, but are structured yet complex

Properties III All living things are descended from a common ancestor* Where did we come from? Does having similar physical traits mean that there is a common ancestor? Three hypotheses of the Origin of Life The Creation Theory A supreme being, God, created the universe and all within The Theory of Evolution Chemical evolution The historic development of a related group of organisms Phylogeny The evolutionary development and history of a species or higher taxonomic grouping of organisms Life arose from an assembly of large molecules Details on this theory in the 2 nd half of the course Extraterrestrial Panspermia Theory that microorganisms or biochemical compounds from outer space are responsible for originating life on Earth and possibly other parts of the universe where suitable atmospheric conditions exist Life was formed elsewhere in the universe and was placed on the newly formed planet Earth

Creationism Evolution

Panspermia

Properties of Life IV Living things regulate use of energy and respond to their environment Via chemical reactions All life depends on chemical reactions that take place within cells Cells, with the aid of enzymes, carry out chemical reactions Cells are able to metabolize Autotrophs Capable of synthesizing all if their organic molecules Hetereotrophs Obtain energy from chemical fuels via oxidation Not able to synthesize all needed materials Some nutrients must be obtained through diet Essential amino acids Metabolic Pathways More to come

Autotroph vs. Heterotroph

Properties of Life V Reproduce All living things share same genetic code Code is passed parent to offspring Asexual Sexual

Properties of Life VI Osmoregulation All life require liquid water Regulate exchange of material across cell membrane Solvents & solutes With the environment Helps maintain differences in and outside of the cell

Properties of Life VII Communication Intra (within) or inter (between) Occurs in individual cells More to come

Properties of Life VIII Animation Movement “stuff” have the ability to move within cells Cells also have the ability to move

Properties of Life IX All living organisms change form and function at different stages of their life cycles Grow Divide Develop Differentiate

Properties of Life X Death Absence of previous 9 properties

Properties of Life Summary Ten Things that Characterize a Cell as Living Cells obey Laws of energetics Cells are highly structured Cells have an evolutionary origin Descendant Cells metabolize Cells replicate (reproduce) Cells osmoregulate Cells communicate Cells show animation Movement Cells grow, divide & differentiate Cells die