nas final enzymes lesson 1
TRANSCRIPT
Agenda
-Introduction-Administrative matters-Getting to know you better-Lesson proper
Adminstrative Matters
• Rules: P R A C T
PunctualityRespectAttitudeCare & ConcernThink• Website: http://carolynkhoo.pbworks.com
1. Recap on Digestion
2. Enzymes
Lesson Objectives
NEW
1. Recap on Digestion
2. Enzymes
Lesson Objectives
5
Digestion
. • Digestion is aided by complex proteins
called enzymes. • The enzymes involved in digestion are
called digestive enzymes.
Digestion is the breaking down of large, complex food molecules into small, simpler molecules
• Nutrients that we learnt:
CarbohydratesProteinsFats
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Nutrients like starch, proteins and fats, are large, complex molecules. They cannot pass through the cell membrane.
Nutrients like glucose and amino acids, are small, soluble molecules. They can pass through the cell membrane.
The cell membrane has small openings (or pores) that allow small molecules to enter, but not large molecules.
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Digestion
. • Digestion is aided by complex proteins
called enzymes. • The enzymes involved in digestion are
called digestive enzymes.
Digestion is the breaking down of large, complex food molecules into small, simpler molecules
Examples of Enzyme and its substrate
Starch maltose glucose
Proteins amino acids
Fats glycerol + fatty acids
sugars
Enzyme Acts on Digested product(s)
Amylase Starch Maltose (a complex sugar)
Maltase Maltose Glucose (simple sugar)
Protease Proteins Amino acids
Lipase Fats Fatty acids and glycerol
1. Biological Molecules
2. Enzymes
Lesson Objectives
NEW
Lesson Objectives
2c. Properties of enymes
2b. Definition of enzymes
2a. Why do we need enzymes?
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzymes
2c. Properties of enzymes
It’s DemoTime!
• Hydrogen peroxide experiment
H2O2
It’s DemoTime!
• Do you believe that there is some reaction going on in this colorless solution?
• Do you believe that enzymes can speed up this reaction?
• What do you observe when the potato cubes are added to the solution?
• Why do you think the detergent was added?• Why do you think KI was added?
Summary of Demo
• Hydrogen peroxide experiment
22H202 2H2O + O2
Breaking downRelease EnergyE.g. The decomposition of H2O2
2H202 2H2O + O2
Anabolic ReactionBuilding upUse up EnergyE.g. Photosynthesis
6CO2 + 6H2OC6H12O6 + 6O2
Catabolic Reaction
VS Enzymes
Enzymes
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzyme
2d. Properties of enzymes
2c. How do enzymes work?
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzymes
2c. How do enzymes work?
2d. Properties of enzymes
Definition of Enzymes
Enzymes are biological catalysts that alters/speed up the rate of a chemical reaction and remains chemically unchanged at the end of reaction.
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzyme
2d. Properties of enzymes
2c. How do enzymes work?
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzyme
2d. Properties of enzymes
2c. How do enzymes work?
Enzyme action
• Enzymes work by lowering activation energy
Q. What is Activation Energy?
Rough representation of Enzyme Action
+Active sites
Substrates Enzyme+Enzyme-substrate complex
products
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzyme
2d. Properties of enzymes
2c. How do enzymes work?
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzyme
2d. Properties of enzymes
2c. How do enzymes work?
Properties of an enzyme
• Speeds up chemical reaction• Required in small amounts• Highly specific in action• Work best at their optimum temperature
and pH• May need co-enzymes for activity
Properties of an enzyme
• Speeds up chemical reaction• Required in small amounts• Highly specific in action• Work best at their optimum temperature
and pH• May need co-enzymes for activity
Properties of an enzyme
• Speeds up chemical reaction• Required in small amounts• Highly specific in action• Work best at their optimum temperature
and pH• May need co-enzymes for activity
Enzymes
2a. Why do we need enzymes?
2b. Definition of enzyme
2d. Properties of enzymes
2c. How do enzymes work?
Summary
Definition of Enzymes
Recap on Digestion
Properties of Enzymes
• Speeds up chemical reaction• Required in small amounts• Highly specific in action• Work best at their optimum temperature and pH• May need co-enzymes for activity
Questions to think about
1. What happens to the rate of enzymatic reactions at very high temperatures? Explain.
2. What are some of the properties of the enzymes that are found in the human stomach?
Q. Are enzymes used in digestion only? What other processes involve enzymes?
Homework
3. Read up textbook pg 77-85 to prepare for short quiz next lesson
4. Check out the following websites:http://www.kscience.co.uk/animations/model.swfhttp://www.dannynicholson.co.uk/enzymetale.swf