Nas Final Enzymes Lesson 1

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