2. Why are chemical reactions important???

3. Chemical reactions allow living things (cells, animals, people, insects) to grow, develop, reproduce, and adapt. Chemical reactions allow living things (cells, animals, people, insects) to grow, develop, reproduce, and adapt.

4. What is a chemical reaction?? The process in which atoms or groups of atoms in substances are reorganized into different substances. The process in which atoms or groups of atoms in substances are reorganized into different substances.

5. How do you know when a chemical reaction has occurred??? Change in appearance Change in appearance Production of heat or light Production of heat or light Formation of a new gas, liquid, or solid Formation of a new gas, liquid, or solid

6. Why Chemical Formulas? Scientists write chemical formulas to describe the substances in a reaction with arrows indicating the process of change. Scientists write chemical formulas to describe the substances in a reaction with arrows indicating the process of change. CO 2 + 2H 2 O → CH 4 + 2 O 2 carbon dioxide and water = Methane + oxygen

7. What is that the chemical equation for?!?!? CO 2 + 2H 2 O → CH 4 + 2 O 2 It’s a fart!

8. The chemical equation shows the reactants, or the starting substances, on the left side of the arrow. The chemical equation shows the reactants, or the starting substances, on the left side of the arrow. CO 2 + 2H 2 O → Carbon dioxide and water

9. The products are the substances formed during the reaction. These are the end results of the reaction and so are shown to the right side of the arrow. The products are the substances formed during the reaction. These are the end results of the reaction and so are shown to the right side of the arrow. → CH 4 + 2 O 2 Methane and Oxygen

10. The arrow is read as “yields” or “react to form.” The arrow is read as “yields” or “react to form.”

11. Remember, matter cannot be created or destroyed! (The Law of Conservation of Mass) Remember, matter cannot be created or destroyed! (The Law of Conservation of Mass)

12. Therefore, it is important that we balance our chemical equations!!! All chemical equations must show this balance of mass (things must be equal on each side.) All chemical equations must show this balance of mass (things must be equal on each side.)

13. But, HOW??? Coefficients are used to make the number of atoms on each side of the arrow equal!!! Coefficients are used to make the number of atoms on each side of the arrow equal!!!

14. Let’s Try One!!! C 6 H 12 O 6 +O 2  C 6 H 12 O 6 +O 2  CO 2 +H 2 O CO 2 +H 2 O Glucose and Oxygen react to form Carbon Dioxide and Water

15. On the reactant side, how many carbons do we have??? On the reactant side, how many carbons do we have??? C 6 H 12 O 6 +O 2 

16. How many hydrogen atoms do we have? How many hydrogen atoms do we have?

17. C 6 H 12 O 6 +O 2  And how many Oxygen atoms?? And how many Oxygen atoms?? Don’t forget to add all of them together…Don’t forget to add all of them together…

18. So we must have 6 Carbon, 12 Hydrogen, and 8 Oxygen on the Products side.  CO 2 + H 2 O  CO 2 + H 2 O Carbon Dioxide and Water What coefficient would need to be placed in front of the carbon to make it 6?

19.  6CO 2 + H 2 O So we must have 6 Carbon, 12 Hydrogen, and 8 Oxygen on the Products side. But now you must multiply the coefficient by the # of Oxygen which is 2. 6x2=12… Hang on to this one. But now you must multiply the coefficient by the # of Oxygen which is 2. 6x2=12… Hang on to this one. How many Hydrogen do we need? How many Hydrogen do we need?

20.  6CO 2 + H 2 O So we must have 6 Carbon, 12 Hydrogen, and 8 Oxygen on the Products side. How can we have 12 Hydrogen??? How can we have 12 Hydrogen??? Multiply the hydrogen by the coefficient… Multiply the hydrogen by the coefficient…

21. So, C 6 H 12 O 6 +__ O 2  6CO 2 +6H 2 O On Reactants Side: On Reactants Side: 6 Carbon 6 Carbon 12 Hydrogen 12 Hydrogen 8 Oxygen 8 Oxygen On Products Side: On Products Side: 6 Carbon 6 Carbon 12 Hydrogen 12 Hydrogen 18 Oxygen 18 Oxygen

22. What # + 6 = 18???? 12!!! 12!!! Can we multiply O 2 by any number and get 12??? Can we multiply O 2 by any number and get 12???

23. Balanced Equation is… C 6 H 12 O 6 + 6O 2  C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O

24. How do reactions occur??? The key to starting a chemical reaction is energy. Think baking cookies!!! The key to starting a chemical reaction is energy. Think baking cookies!!!

25. Most compounds in living things cannot undergo chemical reactions without energy!!! Most compounds in living things cannot undergo chemical reactions without energy!!!

26. Activation Energy is… The minimum amount of energy needed for reactants to form products in a chemical reaction. The minimum amount of energy needed for reactants to form products in a chemical reaction. Ex: Burning a candle Ex: Burning a candle

27. Animal Chemistry- Our Catalysts Remember, a catalyst is a substance that lowers the activation energy needed to start a chemical reaction. Remember, a catalyst is a substance that lowers the activation energy needed to start a chemical reaction. Also, remember that the special proteins that act as biological catalysts are called enzymes. Also, remember that the special proteins that act as biological catalysts are called enzymes.

28. What should I know??? All chemical reactions in living things need catalysts called ENZYMES. All chemical reactions in living things need catalysts called ENZYMES. The reactants that bind to the enzyme in a chemical reaction are called substrates. The reactants that bind to the enzyme in a chemical reaction are called substrates.

29. And, the specific location where a substrate binds on an enzyme is called the active site. And, the specific location where a substrate binds on an enzyme is called the active site. Once the substrate binds to the enzyme, bonds in the reactants are broken down quite easily and new bonds form- the substrates react to form products. Once the substrate binds to the enzyme, bonds in the reactants are broken down quite easily and new bonds form- the substrates react to form products.