pH, Chemical Reaction, & Macromolecule Notes Objectives: B1, B2, B3

pH Acids & Bases Objective: B1 – Describe the difference between acids and bases.

What is an acid?  An acid is a solution that has an excess of H+ ions  The more H + ions, the more acidic the solution

What is a base?  A base is a solution that has an excess of OH- ions  The more OH- ions, the more basic the solution

pH Scale  pH is a measure of how acidic or basic a solution is.  The pH scale ranges from 0 to 14.  Acidic solutions have pH values below 7  A solution with a pH of 7 is neutral.  Basic solutions have pH values above 7.

pH In The Body  Blood pH is regulated to stay within the narrow range of 7.35 to 7.45, making it slightly basic  If our bodies become too acidic or basic, it can denature (destroy the properties of) the proteins (enzymes) in our bodies that do important things like digestion and making copies of DNA

Chemical Reaction Objective: B3 - Identify the parts of a chemical reaction.

Homeostasis - process by which organisms maintain a stable internal environment Examples: - Heart speeds up accommodate the need of oxygen when exercising - Sweat to keep cool - Shiver to help keep warm - Buffering system maintains the blood pH 7.4 (balance)

Chemical Reactions - always involve the breaking of bonds in reactants & the formation of new bonds in products Products Reactants yields What chemical reaction is shown above? __________________ photosynthesis

Macromolecules (macro = large)  Objective:  B2 - Compare the structures & functions of carbohydrates, lipids, proteins, & nucleic acids & their organization into long complex molecules.

 Sometimes referred to as biomolecules because they build life, macromolecules are formed by polymerization in which smaller units called monomers join together to form polymers.  The 4 macromolecules or polymers are: 1. Carbohydrates 2. Lipids 3. Nucleic Acids 4. Proteins