How Would You Make A Cake?

1. How Would You Make A Cake?

2. Objectives • Identify where living things get energy. • Understand how chemical reactions occur. • Identify why enzymes are important to living things.

3. Vocabulary • Energy • Reactant • Product • Activation Energy • Enzyme • Active State • Substrate

4. Changing Matter http://youtu.be/-d23GS56HjQ • Living things are made of matter, which consists of a substance with a form. • In the case of the living, this form is always changing. • This is a constant in the natural world; that changes constantly occur. • Development • Seasons • Metabolism • Etc.

5. Changes • Change usually comes in two forms: PHYSICAL Physical change occurs when only the form or shape of the matter changes (it looks different but contains the same atoms & molecules). CHEMICAL Chemical change occurs when a substance changes into a different substance (the molecules & atoms change into different molecules).

6. A What types of change happened here? PHYSICAL CHEMCIAL B

7. Energy • The necessary ingredient of change is energy. • Energy is the ability to move or change matter. • Luckily, energy is all around us and exists in many forms. • It can be converted from one form to another & with enough education you can cause this conversion yourself, on purpose.

8. Kinetic (Thermal Heat): • Energy of motion • Potential: • Energy that can be used at a later time. • Mechanical: • Energy transferred in machines • Electro-magnetic: • Electrons transferring energy • Nuclear: • Energy stored in the nucleus of atoms • Sound: • Energy in waves • Chemical: • Energy stored in bonds Forms of Energy

9. Changing Matter: Bound by Laws • There are many other constraints on changes in the natural world = Universal Laws • Law of conservation of mass. = Matter is neither created nor destroyed in any change. • This means that any new forms of matter comes from existing matter! • Entropy = As matter changes, some energy is lost as heat to the surroundings • This means with every change some energy is lost forever, requiring refueling. • Law of conservation of energy = Energy may change from one form to another, but the total amount of energy does not change. • This means that any new type of energy comes from energy that has already been here…just in a different form.

10. Changing Matter • Where does this energy come from?... • From heat…from the sun, the Earth’s core, or some other produced source (fires, etc.) • Or from bonds being broken…such as when food is broken down. • See Bonds & Energy at the end…

11. Chemical Reactions • Changing a substance chemically requires a chemical reaction. During this process, bonds between atoms are broken, and new ones are formed. • The bonds are usually through C to C bonds • There are two participants of a reaction • A reactant (aka substrate) is a substance that is changed in a chemical reaction • It’s all the stuff that you start with that mixes and mingles together. • A product is a new substance that is formed. • This is the stuff that you end up with after the mingling.

12. Reactants to Products Reaction Reactants Products

13. Reactants to Products • You will see several reactions in this course. • They are written in the same form: • Reactants  Products • The arrow means “changes to” or “forms” • Sometimes the arrow only goes one way (like from ingredients to cake) and sometimes the arrow goes both ways. • When the arrow goes both directions it shows you that the reactants and products can switch positions… that the reaction can go both ways.

14. Types of Chemical Reactions • There are numerous reactions in the body but 2 main types. • Catabolic: Breakdown Uses the energy stored in bonds • Hydrolysis: ATP  ADP + Pi • Oxidation: • Anabolic: Building Stores energy in bonds for later use • Dehydration: Synthesis of a polypeptide • Phosphorylation: ADP + Pi  ATP • Reduction: • Usually there’s two or more molecules in the reaction & they are often reversible

15. Building & Breaking: Forming the Macromolecules • The anabolic process for the macromolecules is called DEHYDRATION SYNTHESIS. • Water is pulled from neighboring subunits to allow a covalent bond to form between them. • Breaking down the molecules requires the reverse reaction, HYDROLYSIS. • Water is broken down and the resulting H+, OH- is used to split subunits apart.

16. Concept Check • What are the two parts of a reaction and what are they called? • Reactants & Products • How do you show a reaction? • Reactants  Products

17. Activation Energy The processes that form and break down molecules often need a little energy help. Activation Energy is the minimum kinetic energy required to start a chemical reaction • Going through a reaction, or going from reactants to products, can only occur under the right conditions. • The right conditions to start a reaction involve overcoming the natural repulsion between their negatively charged electron clouds. • Remember, like charges repel.

18. Reaction with the correct activation energy

19. Activation Energy: Summation Chemical reactions can only occur when the activation energy is available and the correct atoms are aligned. Activation Energy

20. Activation Energy: Energy of Matter Energy • One of the universal laws, stated by Sir Isaac Newton hundreds of years ago, was that objects in motion stay in motion… • Think of activation energy like motivation. • When you are motivated to get off the couch and start chores or work out it’s like molecules getting the energy to react with each other… • The energy for reactions comes from temperature or how much movement the molecules have…its kinetics. • Sometimes this happens with stirring… = physical • Sometimes this happens with heating… = thermal

21. Activation Energy: Alignment of Matter Alignment is the proper orientation the molecules. • Sometimes, even if enough energy is available, the product still may not form. • When the reactant particles collide, the correct atoms must be brought close together in the proper orientation. • Orientation means the correct parts of the molecules must meet up.

22. In living things, like our bodies, chemical reactions occur between large, complex biomolecules. Biological Reactions • They are happening all the time…millions of reactions per second in every cell. • Many of these reactions require large activation energies to get the ball rolling.

23. Biological Reactions • Reactions are tracked using what’s called a reaction curve. • On the left is the reactants • On the right are the products. • X-axis is time. • Y-axis is energy. • Reactions travel from left to right in time. • Energy required or released is tracked, usually as heat absorbed or released.

24. Biological Reactions ENERGY ABSORBED LINE SEPARATING REACTIONS THAT GIVE OFF ENERGY (RELEASES HEAT) OR TAKE ENERGY AWAY FROM SURROUNDINGS. (FEELS COLDER) ACTIVATION ENERGY NET ENERGY GIVEN OFF OR TAKEN AWAY ENERGY RELEASED

25. Biological Reactions… Enzymes If given enough time most chemical reactions will occur spontaneously, but, in life, time is important. Enzymes • In Essence: Enzymes help reactions happen that may not normally happen or may take too long to happen unaided. • HOW? • An enzyme is a protein that lowers the necessary activation energy of a reaction • Enzymes hold molecules close together and in the correct orientation. • By assisting in necessary biochemical reactions, enzymes help organisms maintain homeostasis.

26. Effect of Enzyme on Activation Energy

27. Enzymes • Enzymes • Each enzyme has anactive site,the region where the reaction takes place. • Each different enzyme acts only on specific substrates. • The shape of the active site determines which reactants, or substrates, will bind to it. • Induced-fit Theory: Binding of the substrates causes the enzyme’s shape to change. This change causes some bonds in the substrates to break and new bonds to form. • Enzymes are not “used-up” in chemical reactions; they’re recycled. • Once the reaction takes place, the product leaves and the enzyme returns back to its original shape.

28. Enzyme Action Enzyme Wrong Orientation = NO REACTION Right Orientation Product AB Reactant A Reactant B

29. Enzyme Action Click to animate the image.

30. Enzymes Enzymes activity is dependent up two main factors; Temperature and pH. • Many enzymes are proteins. • One restraint on proteins is that they are specific to an environment. • Changes in temperature and pH can change a protein’s shape. • Every cook an egg? • If an enzyme changes shape, it won’t work well. • Most enzymes need a certain range of temperatures and pH. • What important property of life ensures this? • Homeostasis • What molecule help us maintain this in our bodies? • Water

31. Enzymes Environmental Affects on Proteins. Normal Activity NORMAL PRODUCTIVITY

32. Temp & pH may change the enzyme’s activity but small changes won’t affect it that much. Large changes will though. Enzymes Environmental Affects on Proteins. VERY RARELY WILL THERE BE AN AFFECT THAT INCREASES PRODUCTIVITY NORMAL PRODUCTIVITY TOO COLD: DOES NOT WORK NORMALLY or PRODUCES LESS

33. Enzymes Denaturing Proteins. Changing the Enzyme’s shape by heating or cooling or by changing the pH too much. Denaturing often destroys the enzyme’s activity. DOES NOT WORK NORMALLY WORKS NORMALLY

34. Enzymes Environmental Affects on Proteins. NORMAL PRODUCTIVITY Denatured = Will not work/no product formed Denatured proteins will not form products.

35. Enzymes & Metabolism Metabolism • Cells get most of the energy needed for metabolism by breaking down food molecules. • What is metabolism again? • Sum of all chemical reactions in an organism. • The release of energy from food molecules occurs in a series of reactions using many enzymes to capture energy in the form of ATP molecules. • ATP is what? • The energy transporter in the body. • The enzymes reduce the activation energy so much that only a little energy is needed to start the reactions. In this process, very little energy is lost as heat.

36. Concept Check • What is Activation Energy? • The energy necessary to start a reaction. • How are enzymes useful? • They lower activation energy to allow chemical reactions to occur by aligning the specific reactants. • Where is the active site? • Where are the reactants? A B C

37. Closure • Any Questions? • Reflect in your warm ups 1 thing you learned today!

38. Classwork/Homework. • Classwork: Work together and complete the “Polar Enzymes Skills Worksheet” • Ask questions if needed. • Homework: Lactaid Case study. Complete and have ready Monday.

39. Case Study • Some people cannot digest certain foods. For example, diabetics cannot digest sugars properly and those that are lactose-intolerant cannot digest milk. Science has been working tirelessly to help solve these problems but one can’t be too sure if the drug companies are honest. • A certain company claims that their drug will help you digest carbohydrates better (like those to combat lactose-intolerance). • You suspect the active ingredient in the product is an enzyme…lactase. • In an attempt to prove the product’s claim you perform an experiment. Your experiment involves 3 individuals; 1 individual with lactose intolerance and consuming milk, 1 person with normal lactose tolerance consuming milk, and 1 lactose intolerant individual consuming milk & the enzyme. You need to analyze the results. Digestive Enzyme

40. Sick/Intolerant Chemical ReactionsAnalyze the illustration of experimental data that tests whether a digestive enzyme supplement works.In-class/Homework Questions: Answer these questions.Due:_______ Pts:_____/25 Healthy/Tolerant • What do the curved arrows represent? • What does the dotted line represent? • What part of a reaction is A? • What are B & C? • Describe which reaction is which? • How do the 2nd and 3rd reactions differ? • Which reaction (2 or 3) would you think uses an enzyme? • What does the enzyme do? • Which reaction gives off heat to the environment? (remember conservation of energy) • Extra Credit***: Explain what this experiment did. What are both ‘A’ & ‘C’?

41. 2. What does the dotted line represent? • What do the curved arrows represent? 3. What part of a reaction is A? 4. What are B & C? 5. Describe which reaction is which. 6. How do the 2nd and 3rd reactions differ? 7. Which reaction (2 or 3) would you think uses an enzyme? 8. What does the enzyme do? 10. Explain what this experiment did. What are both ‘A’ & ‘C’? 9. Which reaction gives off heat to the environment?

42. Chapter 3 Review: Answers

43. Identifying an Enzyme, Word Usage • Breaking a word down • In science, one can easily be confused in trying to find out what a molecule is or what it does • Luckily scientists are smart people and developed patterns to be able to identify the type of word you are reading and what it may do. • Remember: • -ose = sugar (Lactose, glucose), • -ol, -oid = lipid (cholesterol, glycerol)

44. Biological Reactions, continued • Enzymes: • An easy way to tell if a molecule is an enzyme is by the suffix. • Suffix is the word ending • Enzymes start with what they do and usually end in –ase • Protease: Breaks down proteins • Lactase: Breaks down lactose to glucose & galactose • Lipase: Breaks down _____?

45. Summary • Living things use different chemical reactions to get the energy needed for life processes. • An activation energy is needed to start a chemical reaction. The reactants must also be aligned to form the product. • By assisting in necessary biochemical reactions, enzymes help organisms maintain homeostasis.

46. Bonds & Energy • With every change, really called a reaction, the total amount of usable energy decreases because some energy is given off to the surroundings as heat. • Entropy • & Living things get the energy needed for life processes through different chemical reactions that happen inside of the body. • Energy is chemically stored in bonds of molecules and released when the bonds are broken.