First Five  Turn in the Winter Break HW  Grab a packet from the podium  Spend the next 15 minutes reading and working on the packet

Intro to Enzymes

Today’s Objectives  B3-1 Define enzymes as proteins that function as biological catalysts.  B State where, in the alimentary canal, amylase, protease and lipase enzymes are secreted.  B State the functions of a typical amylase, a protease and a lipase, listing the substrate and end-products.

Turn and Talk  What is a “catalyst”?

What are Enzymes?  Biological catalysts that increase reactions rates  Catalysts: substances that speed up reactions w/o being consumed  Biological? Because they are proteins; NOT because they are alive (they aren’t!)

Enzyme-Catalyzed Reactions Hydrogen peroxide (H 2 O 2 ) is broken down into water and oxygen gas  Write the word equation for this reaction. Hydrogen peroxide  Water + Oxygen

Enzyme-Catalyzed Reactions Hydrogen peroxide (H 2 O 2 ) is broken down into water and oxygen gas  Write the balanced symbol equation for this reaction. Hydrogen peroxide  Water + Oxygen

Enzyme-Catalyzed Reactions This reaction is catalyzed by the enzyme catalase. How do we show this in the equation? Hydrogen peroxide > Water + Oxygen Catalase

Enzyme-Catalyzed Reactions In an enzyme reaction, we use the following terms:  Substrate: substance(s) changed by the enzyme reaction (the reactants)  Product: substance(s) produced by the enzyme reaction Hydrogen peroxide > Water + Oxygen Catalase Identify the substrate and the products for the reaction above. Reactant Products

More Practice A. Write the word equation for the examples below. B. Then, identify the enzyme, substrate(s), and product(s) I)Acetylcholinesterase breaks down acetylcholine into acetyl and choline. Enzyme: _________ Substrate(s): _________ Product(s): ________ II)A disaccharide can be broken down into glucose and fructose by lysozyme Enzyme: _________ Substrate(s): _________ Product(s): ________

How Enzymes Work: Mode of Action  With a partner, place the pictures in order (first to forth).  Then, match the pink terms to the appropriate places on the diagram.  Once done, answer these 3 questions in your notebook. 1. What happens to the substrate during the reaction? 2. What happens to the enzyme? The active site? 3. What happens during the 2 nd and 3 rd step in the diagram?

Mode of Action

Discussion Time Why are enzymes so important for life?

Protease Proteases break down proteins. Baby food: As babies can ’ t digest solid food, using protease enzymes makes it easier for a baby ’ s digestive system to cope with it. Proteases are used to produce baby food from cow ’ s milk. The proteases break down milk proteins into amino acids, diminishing the risk of babies developing milk allergies. What else? Animals produce digestive enzymes that break down proteins, such as trypsin and pepsin. Some plants, such as pineapple, have a high protease content. The main enzyme of pineapple is called papain. Many foodstuffs (meat, cheese, fish) also contain proteases or activate them during the process of maturing. The "hanging" of meat activates digestive enzymes that tenderise the meat. Particular proteases are also used for the production of hypoallergenic food. These proteases break down specific allergenic proteins that can cause allergic reactions.hypoallergenic food that can

Carbohydrase: Lactase Lactase is a carbohydrase enzyme which helps to break down lactose (a sugar found in milk) into simple sugars. Lactase is secreted in the intestine to break down the lactose in milk into sugars which can be absorbed. If the enzyme isn ’ t present, the lactose cannot be converted into sugars such as glucose. A lack of this enzyme causes lactose intolerance. The lactose can ’ t be broken down and acts as a great food source for gut bacteria. Carbohydrases are a group of enzymes which digest carbohydrates into the simpler sugars they are made from. The amount of lactase mammals produce tends to decrease with maturity however humans have evolved to keep producing the enzyme into adulthood due to the amount of milk consumed.

Carbohydrase Carbohydrases are a group of enzymes which digest carbohydrates into the simpler sugars they are made from. Used to convert starch syrup, which is relatively cheap, into sugar (glucose) syrup, which is more valuable - for example, as an ingredient in sports drinks. We can get starch from plants eg: corn which is very cheap. Using carbohydrases to convert this to sugar means it is a cheap source of sweetness for food manufacturers Carbohydrases are also used in making fuel from plants (ethanol).

Biological detergents Used to remove stains such as blood, grass, sweat and food from clothes. Biological washing powders contain proteases and lipases. Proteases break down proteins and lipases break down fats in the stains into smaller water soluble substances. They still work at the lower temperatures enzymes work at, which makes washing more environmentally friendly.

Isomerase The enzyme isomerase is normally "immobilised" when used, i.e., it is fixed to a transporter and is not transferred to the product or ingredient on which it is used. Isomerase enzyme is used to convert glucose syrup into fructose syrup. it does this by rearranging the atoms in the glucose molecules. Glucose and fructose contain the same amount of energy however fructose is a sugar which is sweeter than glucose. Using fructose in foods means that less is needed which is why it is used in slimming foods. Food tastes sweet but contains fewer calories!

Enzymes for Digestion  For dinner you eat a bean and cheese burrito. Now what?  Your teeth chewed it to smaller pieces, but then you swallowed. In order to get energy from this, your digestive system needs to break it down even more.  This is done by chemical digestion

Chemical Digestion  Definition: the breakdown of large molecules of food into smaller ones, done by enzymes

Digestive Enzymes Video BEFORE: Use the shaded card cut-outs to fill in the first two columns of the table. DURING: Use the non-shaded cards to fill out the third and fourth columns of the table, based on the info presented. AFTER: 1) Write the word equation for the enzyme-catalyzed reaction. 2) Copy the completed table into your notebook Fill out table based on:

Digestive Enzymes Video Class review of table Fill out table based on:

Exit Ticket Silently answer the following question in your notebook. In 5 minutes, we will trade with partners and peer grade. Why are enzymes referred to as “biological catalysts”?