starter activity: write down as much as you can on a show me board about making proteins
Post on 29-Dec-2015
214 Views
Preview:
TRANSCRIPT
What are enzymes & what do they do?
Your task… Research enzymes using page 14 and 15 of the revision guide. You will present your information using one piece of A4 paper to create a learning tool.
You must include…Properties of enzymes.You should include…Enzyme specificity.You could include…Types of reactions: degradation and synthesis.
Proteins
Learning Intention: Learn the functions of proteins.
Success Criteria: State the functions of proteins
Watch and Listen
• Protein Video Clip
Types of proteins
Structural Enzyme Hormones Antibodies Receptors
Types of proteins
•There are four types of proteins to consider.
1. Structural
• Keratin is an example of a structural protein – it is strong an inelastic to protect hair.
• Collagen- a strong, structural protein found in skin, tendons, ligaments and bones.
2. Enzymes• Enzymes are biological catalysts
that speed up a chemical reaction, while remaining unchanged.
• Examples:-• Amylase is an enzyme found in the
saliva.• Catalase found in every body cell.• Phosphorylase found in potatoes.
3. Hormones• Hormones are chemical messengers
that regulate processes in the body.
• Examples:-• Insulin is a hormone to help control the
concentration of blood glucose in the body.
• Adrenaline is another example of a hormone that is used to regulate heart rate.
4. Antibodies
• Antibodies are Y shaped proteins in the immune system that help to fight infections.
• Antibodies are produced by white blood cells after catching a virus. Eg Chicken pox, Influenza
5. Receptors
• These allow cells to recognise specific substances.
• An examples of this is the receptors that liver cells have to allow them to recognise insulin.
Function of Proteins - SummaryProteins can be • Structural - e.g. Keratin
• Enzymes - e.g. Amylase
• Hormones - e.g. Insulin
• Antibodies - to help the body’s immune system
• Receptors – allows cells to recognise specific substances
Proteins
Learning Intention: Learn the functions of protein.
Success Criteria: State the function of proteins.
Enzymes
Learning Intention: Learn how enzymes work.
Success Criteria: State that enzymes speed up chemical
reactions. State why enzymes are reusable.
Catalyst
• Substances which speed up the rate of a chemical reaction.
• Take part but not changed by reaction.
• Can be used again and again.
• Lower the activation energy.
What is an enzyme?
• Enzymes are biological catalysts that speed up a chemical reaction, while remaining unchanged.
• An enzyme is a chemical made of protein.
• We find them in every living cell.
What does an enzyme do?
• You will now carry out an experiment to investigate what an enzyme does.
• The enzyme you are using is called Amylase.
Test Tube A:
5ml of Starch
2ml of Amylase
Test Tube B:
5ml of Starch
2ml of Water
Food tests recap.
• You may remember food tests from S2.
• Iodine solution turns from brown to blue/black if starch is present.
• Benedicts Solution turns from blue to orange/red if sugar (maltose) is present when heated.
Method1. Collect two test tubes. Label them A and B.2. Add 5ml starch to both test tubes.3. Add 2ml amylase to test tube A and 2ml
water to test tube B.4. Take a few drops of sample A and place
onto a dimple tile, test this with iodine solution and record the results.
5. Repeat this for sample B.6. Take a few drops of sample A and place
this into a test tube containing Benedicts solution, this will need to be heated to obtain your result.
7. Repeat this for Sample B.
ResultsResults• Copy and complete the table.Copy and complete the table.
Method : Now write a brief outline of the method you used in your own words. Remember to mention all the equipment you used and the volumes you measured.
Contents of test tube
Result of test with iodine solution
Result of test with Benedicts solution
Test Tube A: Starch and amylase
Test Tube B: Starch and water
ConclusionConclusion
• The enzyme _________ The enzyme _________ breaks down ______ into breaks down ______ into sugar (Maltose).sugar (Maltose).
amylase
starch
COPY AND COMPLETE
Answers
Enzymes Summary
• An enzyme is a biological catalyst made by all living cells.
• They speed up the rate of reaction.• They are made of protein.• Life could not exist without them.• Amylase is an enzyme that breaks
down starch to sugar.
Enzymes
Learning Intention: Learn how enzymes work.
Success Criteria: 1. State that enzymes speed up chemical reactions. 2. State why enzymes are reusable.
Starter Activity:
Tell your partner three things about an enzyme.
Your teacher will ask you to share.
Enzymes
Learning Intention: Learn what specific means.
Success Criteria: State that enzymes are specific.
Enzymes
• Enzymes have an active site – this is where an enzyme reaction occurs.
• The shape of the active site of enzyme molecules is complementary to a specific substrate.
Enzymes
• Enzymes are specific This means each enzyme only works
on one substrate (e.g. Amylase can only break down starch, nothing
else)
SpecificitySUBSTRATE ENZYME PRODUCT(S)
Starch Amylase Maltose
Fats LipaseFatty Acids &
Glycerol
Protein Pepsin Amino acids
Hydrogen peroxide
Catalase Water + oxygen
Glucose-1-phosphate
Phosphorylase
Starch
Lock and Key Hypothesis
Each enzyme is specific and only works on one substrate- like a lock and key.
Enzyme Action
• Enzyme action results in product(s) being formed.
• This can be through a degradation reaction – when something is broken down into something smaller.
• This can be through a synthesis reaction – when things are built up together to make something bigger.
Enzymes
• You are going to carry out an investigation to find out if enzymes are specific.
• Think about how you might do this.
• Discuss your hypothesis with your lab partner
One Enzyme – One Reaction.
• Copy and complete the diagram above. Make sure that you use a ruler!
2ml Hydrogen peroxide + 2ml catalase
2ml Hydrogen peroxide + 2ml amylase
Method
• 1. Collect two test tubes. Label them A and B.
• 2. Add 2ml hydrogen peroxide to each.
• 3. Add 2ml catalase to test tube A and 2ml amylase to test tube B.
• 4. Record the height of foam in each test tube.
Results
Contents of test tube Height of foam (cm)
2ml hydrogen peroxide + 2ml
catalase.
2ml hydrogen peroxide + 2ml
amylase.
Conclusion
• In test tube A what happened?
• Why did this happen?
• In test tube B what happened?
• Why did this happen?
• What do both these results show us?
Enzymes
Learning Intention: Learn what specific means.
Success Criteria: State that enzymes are specific.
Enzymes
Learning Intention: Learn the effects that different conditions
have on enzymes
Success Criteria:State two conditions that affect enzyme
activity. State what the term denatured means.
Starter
• Think about what might happen if the active site of an enzyme changed shape?
• What might make it change shape?
Factors that affect enzymes
• There are two factors that affect enzyme activity.
• These are pH and temperature.• Each enzyme has its own set of
optimum conditions. This means the conditions it works best at.
• If these are altered, it affects the rate at which an enzyme works
Factors affecting enzymesIf the temperature and pH changes sufficiently beyond an enzyme’s optimum, the shape of the enzyme irreversibly changes.
normal denatured
heat
pH
This affects the shape of the active site and means that the enzyme will no longer work.
When this happens the enzyme is denatured.
Temperature• All enzymes are made of
protein, and proteins are denatured at high temperatures (above about 50°C).
• The rate of enzyme activity increases with temperature up to the optimum temperature.
• After that it decreases to zero as the enzyme is denatured.
Task
• Discuss as a class how you would carry out an investigation to see the affect of temperature on enzyme activity.
• You will then carry out this investigation.
pH• pH also affects the rate of enzyme activity.
Each enzyme has its own range of pH in which it will work.
ExamplePepsin
(stomach)
ExampleSalivary Amylase
(mouth)
ExampleCatalase
(liver)
Task
• Discuss as a class how you would carry out an investigation to see the affect of pH on enzyme activity
• You will then carry out this investigation
Task:
Using props or actions, explain the lock and key theory to your partner.
Your teacher may ask the person with the best explanation to share with the rest of the class.
Enzymes
Learning Intention: Learn the effects that different conditions have
on enzyme activity.
Success Criteria:State two conditions that affect enzyme
activity.State what the term denatured means.
Section 1- 4 revision.
• Your task – To produce a revision guide on your given section of topics 1-4.
• The challenge – You have one lesson to prepare your revision guide with your group which you will then use for revision with the rest of the class.
• The criteria - It can be in whatever form you choose – booklet, video, poster.
• It must cover all outcomes for that topic. • Every member of the group must have a copy of
the revision guide.• It must include ‘End of topic test questions’ at the
end based on the outcomes.
top related