2.3 - 2.5 Study Guide 2.3—Carbon Compounds Monomer – small repeating units Polymer – large molecules Polymerization - process that joins small repeating units (monomers) together to form large molecules (polymers) o Dehydration synthesis - removes water (dehydration) to make a bond (synthesis) o The opposite process is Hydrolysis Hydrolysis adds water (hydro) to break a bond (lysis) There are 5 important carbon-based molecules in all organisms 1) Carbohydrates 2) lipids 3) nucleic acids 4) protein 5) ATP MOLECULE Carbohydrates PICTURE ELEMENTS C,H,O MONOMERS POLYMERS USE Monosaccharides Polysaccharides Quick energy source in body Lipids C,H,O Glycerol Fatty acids Fat, lipid Long term energy source in body Nucleic acids C,H,O,P,N Nucleotides Nucleic Acid DNA RNA Instructions to make proteins in body Proteins C,H,O,S,N ATP C,H,O,P,N Amino acids --- Polypeptides Proteins --- Many uses: movement (muscle), structure, ENZYMES!! Major energy carrying molecule in cell 2.4—Chemical Reactions o Reactants—what goes into a reaction o Products—what comes out of a reaction Depending on the change in energy, two different reactions can occur o Endothermic reactions absorb more energy than they release o Exothermic reactions release more energy than they absorb 2.5—Enzymes Sometimes reactions happen too slowly for our bodies catalyst substance that speeds up a chemical reaction by decreasing the activation energy needed o Catalysts are not used up in a reaction o In our body, we have protein-based catalysts called enzymes UNDERSTAND THE FOLLWOWNG CONCEPTS For a chemical reaction to work, the substrate(s) (reactants) must attach to the active site on the enzyme. The shape of an enzyme is crucial to how it functions o Referred to as the lock and key model Enzymes (and proteins) can easily be deactivated if their shape changes due to changes in the environment o pH, and temperature changes can affect the shape of the enzyme.