Carbon Structures & the Origin of Life The presence of life is built around the carbon atom's ability to form many different shapes and bond types. As carbon binds to H, O, N, P, & S the building blocks of life are formed. – The ratio of atoms is fairly consistent in every living thing but the shape and complexity differ with each species. – Organic chemistry is the branch of science that concentrates specializes on the study of organic structures (both inorganic and organic) and their function. – It was originally thought that the organic compounds from living things could only come from other living things. This belief was the foundation of vitalism and steered the study of organic chemistry until 1953 when Stanley Miller synthesized Urea (an organic compound produced in the kidneys) and other compounds in an experiment mimicking primordial Earth. – This new discovery led to a transition from vitalism to mechanism. The mechanism thought process viewed that ALL process, both organic and inorganic, are governed by physical and chemical laws.

Carbon Basics - Bonds Carbon is tetravalent. It is a quality shared by no other non-metal. – Forms single, double, & triple covalent bonds that can be rearranged to form new substances with differing conformations The conformation is governed by the 3-D structure that gives the molecule its biological function

Carbon Basics - Bonds CO 2 is the ultimate source of carbon for all organic molecules – Inorganic – Supports the foundation for the biogeochemical carbon cycle Carbon atoms will bond to each other to assemble the carbon skeleton used to form the complex macromolecules that support life

Carbon Basics - Isomers Same chemical formula with a different arrangement of atoms – Structural…differs in covalent arrangement of atoms – Geometric…same structural formula with different spatial (3-d) arrangement -cis & -trans – Enantiomers Are mirror images of each other Only one is biologically active Even mixtures are called racemic L-Animal & D-Plant

Carbon Basics – Functional Groups The function of a molecule is not solely dependent on the carbon atoms but also on the functional groups attached Common functional groups

Functional Groups