Warm UP Name one type of chemical bond and tell me how it bonds. What is an endothermic reaction? Write an example equation for this type of reaction. Draw a picture showing how the activation energy helps a reaction. How does it help? Can you list one function of any of the following on your body: carbohydrates, proteins, lipids or nucleic acids?

Chemical Reactions Chemical Reaction – a process that changes one set of chemicals into another. Involves the breaking and forming of new bonds. Quantity remains the same. 1 + 1 = 2 1 + 1  2 If this represented a chemical reaction, then 1=reactants and 2 = product The reactants “react” to form the product.

Chemical Reactions A + B AB Synthesis/Anabolic Reaction: when two or more atoms bond to form a more complex structure. Example: fixing worn or damaged tissues requires a build up of smaller molecules coming together to make a larger molecule. A + B AB

Chemical Reactions AB A + B Decomposition/catabolic reaction: When a bond holding atoms together breaks and produces a simpler molecule. Example: Is needed for foods to be digested and energy to be released for your body to use. AB A + B

Activation Energy All reactions need energy to occur. Activation Energy – refers to the energy needed to get the reaction started For example, you must apply force when striking a match to get the fire to start. Rollercoaster example

Activation Energy Endothermic Reactions- Requires energy “in” to complete reaction. Notice the different energy levels between the reactants and products. Example: photosynthesis – reactants of water and CO2 and energy from the sun (activation energy) creates products of Glucose and O2.

Activation Energy Exothermic Reaction- Releases Energy “out” during the reaction. Notice the different energy levels between the reactants and products. Example: combustion reactions of fuels. 1 ask 2 “do you think Exothermic reactions are anabolic or catabolic and why?”

Catalysts Catalyst - a substance that lowers a reactions activation energy In other words, speeds up the reaction. Enzymes Biological Catalysts are called Enzymes. They speed up chemical reactions in the cells. However they are not essential, for the reactions can occur on their own

Enzymes The names of enzymes typically end in “-ase” For example: protease splits proteins into its monomers - amino acids. What do you think carbohydrase does? Splits carbohydrates (polysaccarides) into its monomers - monosaccarides. Also used for: protein synthesis, synthesis of RNA and DNA, etc.

STOP POINT! Chemical Reactions Review worksheet.