Enzymes. Essential Question: Why are the actions of an enzymes important to us?

Transcription

1 Enzymes Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors such as ph and temperature, and their effect on enzyme activity.

2 Enzymes Objective: Analyze the role of enzymes in organisms and Interpret a graph of the effect of an enzyme on the activation energy in a chemical reaction. Analyze the role of enzymes in organisms. Essential Question: Why are the actions of an enzymes important to us?

3 Enzyme Lab Review What is the affect of concentration on enzyme reaction rate? How do you know based on your results? What is the effect of Temperature on enzyme reaction rate? How do you know based on your results? What is the affect of ph on enzyme activity? How do you know based on your results?

4 Types of Reactions: Exothermic Exothermic: overall, energy is released by the reaction Extra energy Activation Energy given off as heat, light, etc. Ex: fireflies, fire, Total Energy Released fireworks Reactants Products

5 Types of reactions: Endothermic Endothermic: overall, energy is absorbed by the reaction The reaction will feel cold Ex: chemical ice Packs, Photosynthesis Activation Energy Total Energy Released Reactants Products

6 Check for Understanding Identify the reaction as endothermic or exothermic. Exothermic!

7 Check for Understanding Identify the reaction as endothermic or exothermic. Endothermic!

8 Check for Understanding Identify the reaction as endothermic or exothermic. Endothermic!

9 Check for Understanding Identify the reaction as endothermic or exothermic. Exothermic!

10 Check for Understanding Identify the reaction as endothermic or exothermic. Exothermic!

11 Check for Understanding Just for fun

12 Remember sugar. What do they all end with? Fructose Sucrose Galactose Lactose -OSE What if I told you that there was a protein.. pause for dramatic effect. that helped break down the sugars in your body dramatic effect #2.. and they all end in ase!!!

13 Catalysts A catalyst makes it easier for reactions to begin by decreasing activation energy and increasing the rate of reaction Predict: how would the graph of this reaction change if a catalyst was added?

14 Activation Energy Activation Energy: the energy required for a reaction to begin Like the energy needed to push a ball up a hill; once at the top, the ball will roll down the other side of the hill on its own

15 Enzymes Enzymes: are Proteins that increase reaction rate and decrease activation energy Enzymes are catalysts in living things Needed for almost all processes of life to occur Digestion, building proteins, the immune system Allow the products of a reaction to form quicker

16 Which of the shapes on the right will combine with the L on the left, to complete the square (objects can only be rotated, not flipped) L Square 4 5

17 Enzymes The structure of an enzyme allows only certain compounds to interact (bind) with it substrates (reactants The compound that bind to the enzymes are called substrates (reactants) Substrates bind at specific places called active sites, this is where the reaction occurs Once the reaction is finished, called the product Active site enzyme

18 Substrates bind to an enzyme at certain places called active sites. The enzyme brings substrates together and weakens their bonds. The catalyzed reaction forms a product that is released from the enzyme. Lock-and-Key Model of Enzymes Lock and-key: Substrates (reactants) fit the activation site on the enzyme the way a key fits into a lock The substrates bonds weaken, and a new product forms

19 In other words You re PERFECT!! Enzymes are like you and your one true love: no one else fits quite like the two of you ;)

20 How do enzymes work? Enzymes often only work within a narrow range of conditions by weakening bonds Since enzymes are proteins, they depend on being the correct shape to function (macromolecules) If conditions change, denature enzymes denature= unfold or chance the shape of the enzyme enzyme enzyme

21 What factors affect the rate at which an enzyme works? 1.Temperature 2.pH 3. Concentration

22 Temperature and Enzymes Rate of reaction increase as temperature increases Extreme temperatures are dangerous High temperatures may denature (unfold) the enzyme Draw graph in notes!

23 Girl, your so hot you denature my proteins

24 ph and Enzymes Enzymes function at optimal ph Outside its optimal range, the enzyme is denatured Draw graph in notes!

25 Concentration and Enzymes Concentration- the relative amount of a given substance contained within a solution When concentration of enzymes increases, the reaction rate will also increases until it is saturated Draw graph in notes!

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27 Check for Understanding As food travels through the digestive system, it is exposed to a variety of ph levels. The stomach has a ph of 2 due to the presence of hydrochloride acid (HCl), and the small intestine has a ph ranging from 7 to 9. HCl converts pepsinogen into pepsin, an enzyme that digests proteins in the stomach. Which of the following most likely happens to pepsin as it enters the small intestine? A. It begins to replicate B. It becomes inactive. C. It's shape changes to engulf large proteins. D. It's activity increases to digest more proteins.

28 Check for understanding The graph below shows how the activity level of three different enzymes varies with ph. Based on the information in the graph, what can be determined about the activity of these enzymes? A. Each enzyme is active at a certain ph range. B. Enzyme C is most active in a neutral ph. C. Each enzyme will react at all ph levels. D. Enzyme A will react only at ph 7.

29 Check for understanding In living cells, enzymes act as catalysts, which may reduce the amount of activation energy required for a chemical reaction to occur. In the graphs below, pathway x is a solid line representing the uncatalyzed reaction. The dotted line shows the catalyzed reaction. Which graph best illustrates the changes in a reaction when the catalyst reduces the amount of energy required?

30 Enzyme Graphing Independently read the background info. In groups, graph the effects of Temp, ph, and concentration with the given data set. Answer the analysis questions. C reading, level 0; graphing, level 2 H- Ask 3 before me, raise silent hand to get me A- Complete enzyme graphing activity M- remain in assigned table seat P- work with your group mates, not everyone in the room SUCCESS!

31 EXIT TICKET! Clear your desk!