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Do Now What are the functions of these macromolecules: 1. Carbohydrates (polysaccharides) 2. Lipids 3. Proteins 4. Nucleic Acids Do Now 1. How is a cell receptor similar to an enzyme? 2. How is a cell receptor different from an enzyme? 3. Are enzymes organic? Why? DO NOW 1. Enzymes, hormones and cell receptors are examples of which type of macromolecule? 2. How are enzymes, hormones and cell receptors different from one another? Enzymes - Do Now 1. How can we break down a piece of pepperoni pizza? 2. What is the pizza broken down into? 3. Can those nutrients be synthesized into new molecules? How? Enzymes & pH http://phet.colorado.edu/sims/html/ph-scale/latest/ph-scale_en.html Chemical reactions with enzymes are used to break molecules down and… Carbohydrate Monosaccharide + Monosaccharide Lipid Fatty acid + Fatty acid Protein Amino acid + Amino acid Nucleic Acid Nucleotide + Nucleotide Chemical reactions with enzymes are used to break molecules down and Synthesize large molecules Monosaccharide + Monosaccharide Carbohydrate Fatty acid + Fatty acid Lipid Amino acid + Amino acid Protein Nucleotide + Nucleotide Nucleic Acid Wait, what’s a chemical reaction? When one or more substances react to form new substances. Na + Cl Silver solid Green gas NaCl Table Salt The substances that react. Reactants Na + Cl The substances that are produced. Products NaCl Why do we need enzymes?? Isn’t water all you need to break down & synthesize molecules? Lets take a look: (Think about these 2 questions while observing) http://lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html 1. Will molecules breakdown or synthesize without enzymes? Yes, but much slower (slower rate) 2. Why are enzymes important for chemical reactions? Enzymes speed up chemical reactions. Allow reactions to happen more often. Hmmmm… 1. Does a Jolly rancher or Starburst dissolve faster in your mouth or a glass of water? It will dissolve faster in your mouth 2. Why might this happen? Because enzymes speed up the breakdown process! How could you speed up this chemical reaction? Adding enzymes! Enzyme doing Hydrolysis Do Now “Complex” 1. Why are enzymes necessary for living organisms? Allow chemical reactions to happen fast enough to maintain homeostasis 2. How are enzymes different from one another? Enzymes all have specific shapes for specific reactions 3. Can chemical reactions occur without enzymes? Explain. Allow chemical reactions to happen fast enough to maintain homeostasis Enzymes Enzymes: Are organic catalysts that speed up chemical reactions Catalyst – something that speeds up a reaction Example: Carbon Dioxide and Water come together to make Carbonic Acid – Happens in red blood cells, but only about 200 molecules of carbonic acid form an hour – Add the enzyme carbonic anhydrase, and an estimated 600,000 molecules of carbonic acid are now formed every second! Enzymes Enzymes are very specific. Each enzyme only has one reaction it will help Example: Lactose (a disaccharide), will only be broken down by the enzyme lactase Maltose will only be broken down by maltase Starch (amylose) will only be broken down by amylase Proteins will only be broken down by protease (peptidase) Wait a minute… what do you notice about many enzyme names? Protease, amylase, maltase, lactase, lipase… Using words alone, how can you tell which word is a sugar and which is an enzyme? (label the sugar and enzyme) Amylase vs. Amylose Why do enzymes only help catalyze (speed up) only one type of reaction? Enzyme shape allows only certain reactants (substrates) to bind to the enzyme – Substrate: the specific reactants that an enzyme acts on – Active site: the part of the enzyme where the substrate connects. Specific to only one substrate! • Substrate + active site = like a lock and key! Specific, Picky Enzymes (Plays hard to get!) Lets take a look at how enzymes are specific: http://lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html When watching, keep in mind these questions: 1. How are the enzymes shown different? **Remember: SUBSTRATE - ENZYME Label your diagram Word Bank… don’t get used to this Enzyme (2x) Substrate Products Reactants Active Site Enzyme-Substrate Complex 1. Look at the active site. Did it change after the reaction? 2. Exit Question – Write a sentence or two stating the conclusion or relationship between the active site and the specific substrate. 3. Bonus question – can this enzyme be used again for the same reaction? For a different reaction? Do Now (4) 1. Write sentences describing the relationship between: Active Site / Specific Substrate Enzyme / Breaks down, Synthesis Enzymes / “ASE” Enzyme / Catalyst Bonus Question Example: Amylase only breaks down starch (amylose) – Which molecule is the enzyme and which is the substrate? Enzymes are Reused Over and Over and Over again 1. What type of reaction is this (break down or synthesis)? 2. What changed in this reaction? 3. What stayed the same? Enzymes are Reused Over and Over and Over again Your conclusion? http://lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html Enzymes = Specific, Picky and High Maintenance The rate at which enzymes catalyze their reactions changes as the conditions inside the cell change! Conditions that effect enzyme reaction rate are: 1. Temperature 2. Relative concentrations of enzyme and substrate 3. pH (acidic, basic, neutral) Temperature affects Enzyme Function To cold = enzyme works to slow To hot = enzyme begins to denature! – Denature = proteins begin to break apart at high temperatures changing the active site!! Why is this bad? If the active site is changed, that specific reaction can’t happen! Every enzyme has an optimal temperature it works best at! Why is a very high fever considered dangerous where you have to go to the hospital? http://lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html pH affects Enzyme Function What is pH? – Measures how acidic or basic a solution is Acids – compounds that release H+ ions in solution (corrosive) Bases – compounds that remove H+ from solution pH scale - measures how acidic a solution is – pH = usually between 0 -14 – pH 0 = very acidic (high H+ concentration) – pH 14 = very basic (low H+ concentration) – pH 7 = neutral (not basic or acidic) pH What is basic and what is neutral? What is the pH of human blood? What is the pH of water? Acids vs. Bases How do we test the pH of a solution? Using litmus paper! Litmus paper turns this color when: 1. Acidic 2. Basic What color did the litmus paper turn with: • Lemon juice – • Bleach – pH affects Enzyme Function Just like temperature, enzymes (proteins) will start to breakdown permanently if the pH is not what the enzyme needs! 1. Do all enzymes work best at the same pH? 2. What is the optimum rate for Gastric Protease in graph B? Most enzymes work best in neutral solutions B pH affects Enzyme Function • Humans need to keep their pH within a very narrow range around neutral (pH 7.0). – Some organisms need different pH ranges • The azalea plant thrives in acidic (4.5) soil • The microorganism Picrophilus survives best at an extremely acidic pH of 0.7 (lowest among all organisms) Enzyme-Substrate Concentration Enzymes can only catalyze so fast. – If you keep adding substrates, the enzymes reaction rate will go up – At a certain point, enzymes can not work any faster and the rate will not increase! It will level off! Why does the reaction rate line level-off or flatten out? Summary of Diagrams you will see Questions 1. Do all enzymes react best at the same temperatures? 2. Do all enzymes react best at the same pH? 3. What is pH a measure of? 4. What happens to an enzyme when it is to hot or acidic? Do Now(1) On a separate sheet of paper Put in size order: – Enzymes – Amino acid – Cell organelle – Cell – Atom – Tissue – Organ Do Now lab1 1. Describe enzymes: 2. What is a reaction? 3. When referring to rate of reaction, what do we mean by rate? 4. If you constantly add more substrate, increasing concentration, will the rate of reaction always increase? Do Now 1. How would you create this graph? lab2