Chemistry of Life Organic chemistry is the study of carbon compounds ALL living things are made of carbon compounds Can measure the amount of C remaining (half-life) to determine the age of fossils C atoms are versatile building blocks of life Good bonding properties Can form 4 stable covalent bonds with many other elements H Carbon chemistry = organic chemistry Why is it a foundational atom? What makes it so important? Can’t be a good building block if you only form 1 or 2 bonds. H C H H

Why study carbon? All of life is built on carbon Cells ~72% H2O ~25% organic carbon compounds carbohydrates lipids proteins nucleic acids ~3% salts Na, Cl, K… Why do we study carbon -- is it the most abundant element in living organisms? H & O most abundant C is the next most abundant

Carbon compounds Used to build life Smaller molecules called monomers are joined together to form larger molecules called macromolecules or polymers 4 major classes of macromolecules built on C, H, O, N, P: carbohydrates lipids proteins nucleic acids

Organic compounds

Functions of organic compounds Carbohydrates Source of energy and help strengthen cell walls, and communication Lipids Source of energy, insulation, storage, protection, forms cell membrane Proteins Source of energy, form traits, hormones, transporters, muscle contraction Nucleic acids Stores and transmits genetic information

Proteins Most structurally & functionally diverse group Function: involved in almost everything enzymes (pepsin, DNA polymerase) structure (keratin, collagen) carriers & transport (hemoglobin, aquaporin) cell communication signals (insulin & other hormones) receptors defense (antibodies) movement (actin & myosin) storage (bean seed proteins) Storage: beans (seed proteins) Movement: muscle fibers Cell surface proteins: labels that ID cell as self vs. foreign Antibodies: recognize the labels ENZYMES!!!!

Proteins Protein functions depends on protein structure Structure depends on DNA sequence Codes for amino acid sequence Order of amino acids determine structure and function Forms a polypeptide chain Amino acids joined by peptide bond protein can be one or more polypeptide chains folded & bonded together Rubisco = 16 polypeptide chains Hemoglobin = 4 polypeptide chains (2 alpha, 2 beta)

Enzymes are important proteins https://www.bing.com/videos/search?q=enzyme+animation&&view=detail&mid=EEC72AA4F1750774DEAAEEC72AA4F1750774DEAA&rvsmid=EEC72AA4F1750774DEAAEEC72AA4F1750774DEAA&fsscr=0&FORM=VDFSRV Enzymes are important proteins substrate Reactant or the molecule being broken down product end result of reaction active site enzyme’s catalytic site; substrate fits into active site Active site puts “stress” on the substrate bonds active site products substrate enzyme

Enzymes Enzymes are substrate specific Enzyme What is an enzyme? Enzymes are proteins that speed-up the rate of a chemical reaction- also known as a catalyst Aid in many cellular processes Ex: amylase in digestion Breaks down a substrate known as starch Bread (starch) is the substrate and amylase breaks it down into smaller products quickly If the bread was left to breakdown on its own it could take YEARS! Enzymes work by decreasing the activation energy also known as the start-up energy of a reaction Enzyme Enzymes are substrate specific

Pheeew… that takes a lot less energy! Reducing Activation energy Enzymes are catalysts reduces the amount of energy needed to start a reaction This increases the rate of the reaction Pheeew… that takes a lot less energy! uncatalyzed reaction catalyzed reaction NEW activation energy reactant product

In Biology, size doesn’t matter, Protein denaturation In Biology, size doesn’t matter, SHAPE matters! Proteins have “optimal” environments they function best b/c of their AA sequence Unfolding a protein conditions that disrupts bonding temperature pH salinity alter 3-D shape destroys functionality some proteins can return to their functional shape after denaturation, many cannot