2-4 Chemical Reactions and Enzymes

Chemical Reactions Process of changing one set of chemicals into another set of chemicals Demonstration: Reactants (what enters a reaction) Products (what is produced) H2O + CO2 + sunlight → C6H12O6 + O2 water + carbon dioxide + sunlight → glucose (sugar) and oxygen Notice: Chemical reactions involve changes in chemical BONDS 11/23/2018

Energy Reactions Some chemical reactions release energy and others absorb Chemical reactions that release often occur spontaneously Reactions that absorb energy will not occur without a source of energy 11/23/2018

http://sisnet. ssku. k12. ca http://sisnet.ssku.k12.ca.us/%7Emsusdftp/fleisch/projects/gummybear/gummy http://www.chemistry-videos.org.uk/chem%20clips/KS3%20Endothermic/enothermic.html http://www.bing.com/videos/search?q=gummy+bear+reaction&form=QBVR&qs=n&adlt=strict#first=41 11/23/2018

Chemical Reactions Activation energy – energy needed to get a reaction going. Energy-Absorbing Reaction Energy-Releasing Reaction Sugar + O2 Products Activation energy sunlight Sugar + O2 Activation energy CO2 + H20 Reactants CO2 + H2O Reactants Products Won’t occur without constant source of energy Occur spontaneously or with a little “boost” 11/23/2018

Enzymes Catalyst – substance that speed up chemical reactions. The MATCH Enzyme – Protein. Biological Catalyst. Used in cells to speed up chemical reactions. We can’t have a MATCH in our bodies. We would overheat!!! Cells use enzymes to speed up chemical reaction by lowering the amount of activation energy needed to get the reaction 11/23/2018

http://videos. howstuffworks http://videos.howstuffworks.com/discovery/28733-assignment-discovery-enzyme-catalysts-video.htm http://www.teachertube.com/viewVideo.php?video_id=123460&title=A_Catalyzed_Reaction 11/23/2018

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Enzyme Action Reactants (could be food you eat) Lock and key 11/23/2018

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