first five turn in the winter break hw grab a packet from the podium spend the next 15 minutes...
TRANSCRIPT
First FiveTurn 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 ObjectivesB3-1 Define enzymes as proteins that function
as biological catalysts.
B4.3-12 State where, in the alimentary canal, amylase, protease and lipase enzymes are secreted.
B4.3-13 State the functions of a typical amylase, a protease and a lipase, listing the substrate and end-products.
Turn and TalkWhat 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 (H2O2) is broken down into water and oxygen gas
Write the word equation for this reaction.
Hydrogen peroxide Water + Oxygen
Enzyme-Catalyzed Reactions
Hydrogen peroxide (H2O2) is broken down into water and oxygen gas
Write the balanced symbol equation for this reaction.
Hydrogen peroxide Water + Oxygen
Enzyme-Catalyzed ReactionsThis reaction is catalyzed by the enzyme catalase.
How do we show this in the equation?
Hydrogen peroxide --------------> Water + OxygenCatalase
Enzyme-Catalyzed ReactionsIn 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 + OxygenCatalase
Identify the substrate and the products for the reaction above.
ReactantProducts
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 ActionWith 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 2nd and 3rd 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.
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: https://www.youtube.com/watch?v=vTQybDgweiE
Digestive Enzymes Video
Class review of table
Fill out table based on: https://www.youtube.com/watch?v=vTQybDgweiE
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”?