Enzymes

Front 1

Define Enzymes (6)

Back 1

1. Biological catalysts

2. made up of proteins

3. that lower the activation energy required

4. for a chemical reaction to occur,

5. speeding up the rate of chemical reactions

6. without themselves being chemically changed at the end

Front 2

Why Enzymes are needed: (4)

Back 2

1. Food stains (Proteins, Carbohydrates, Fats) molecules too big

2. Insoluble in water

3. Enzymes digest nutrients in food to 3S

S. mall

S. oluble

S. imple

4. So that they can pass through the cell membrane

Hint 2

Stains =

P. ro

C. arry

F. iora

Front 3

Define Catalysts (2)

Back 3

1. substance that alters/speeds up the rate of chemical reactions

2. Without being chemically changed at the end

Front 4

Define Activation Energy

Back 4

The energy needed to start a chemical reaction.

Front 5

Digestive Enzymes (4)

Back 5

1. Amylase - Starch > Maltose

>

2. Maltase - Maltose > Glucose

3. Pepsin - Protein > Polypeptide

4. Lipase - Fats > Glycerol + 3 Fatty Acids

Front 6

Define Anabolic Reactions

+

One Example

Back 6

Building Up Reactions

Eg.

1. Amino Acids > Polypeptide (chains)

2. Fatty Acids + glycerol > Fats

3. Glucose > Starch/Glycogen

Front 7

Define Catabolic Reactions

+

One Example

Back 7

Breaking Down Reactions

Eg. Breaking down of Glucose during respiration

1. Digestion of Food Substances

2. Starch > Glucose

3. Glucose > Oxygen (Cellular Respiration)

Front 8

Define Hydrolases

Back 8

Enzymes that catalyze Hydrolytic Reactions

Front 9

Characteristics of Enzymes (3)

Back 9

1. Speed up chemical reactions

2. Only required in minute amounts

3. Highly specific in action

(Due to its 3D shape)

Front 10

Lock & Key Hypothesis (6)

Back 10

1. Reactions depends on active site.

(Enzyme specific 3D shape, active site present)

2. Only Substrate w/ 3D shape complementary to active site can bind & FIT into the enzyme

3. to form enzyme-substrate complex

4. substrate > products

5. Products detach from active site

6. enzyme chemically unchanged

(can be reused again)

Front 11

Define Denaturation (4)

Back 11

1. The change in 3D shape

2. of an enzyme or any protein

3. caused by extremely High Temp.

4. or extreme pH.

Front 12

What happens when an enzyme is denatured (6)

Back 12

1. Weak Hydrogen Bonds are broken.

2. Loss of 3D structure & active site.

3. Cannot bind with substrate.

4. No enzyme-substrate complex formed.

5. No reaction takes place.

6. No product is formed.

Front 13

Affected By Temperature

(graph desc. in 4 parts)

Back 13

A: Low Temp:

Enzymes are inactive.

Very Low:

1. K.E.

2. Chances of substrate molecules colliding with enzymes.

B: Temp increases

As the temp. ^,

Increases:

- Enzyme activity

- K.E. of molecules

- Rate of collision between substrate & enzyme

- Rate of formation of enzyme-substrate complex

C: Optimum Temp.

"point where rate of reaction is highest, where enzymes are most active"

D: Beyond C,

- enzyme activity decreases

- HIGH temp BREAKS the weak Hydrogen bonds within the enzyme, changes its 3D shape

- Active site loses its 3D shape

- Denatured

Hint 13

Divide the graph into 4 parts

Front 14

Affected by pH

Back 14

Extreme changes denature enzyme, cause it to lose function

- Some proteins extreme pH

Eg: Pepsin in stomach, pH 2-3

Front 15

Amino Acid Structure:

Back 15

H H O

l l ll

H - N - C - C - OH

l

R

Hint 15

Amino Group ( H - N ^l H )

Side Chain (R)

Carboxylic Acid Group

Front 16

Define Catalase (2)

Back 16

- Enzyme that catalyzes breakdown of Hydrogen Peroxide

- Into H20 + O2