Lesson Essential Question

What is the function of enzymes in living organisms?

Copy the EQ in your notebooks.

Lesson Headings

• What are enzymes?

• Why are enzymes specific?

• Why are enzymes "reusable?"

• How do enzymes speed up chemical reactions?

• What is a denatured enzyme?

• What are some real world application of enzymes?

What are enzymes?

Organic Molecule 4: Proteins

ENZYMES
“Biological Catalyst”

▪Functions:

▪Type of Protein that speeds up reactions.

Breaks food and other molecules down in the body.

Organic Molecule 4: Proteins

ENZYMES

▪Substrate-any molecule that an enzyme breaks down.

▪Enzymes are specific. They can only break down one type
of substrate!
▪Active Site: the spot on an enzyme that the substrate fits
into.

Why are enzymes specific?

Organic Molecule 4: Proteins

ENZYMES
▪Lock and Key: Enzymes fit into the substrate like a key fits into
a lock.
▪Enzymes have a SPECIFIC shape and structure.

Why are enzymes reusable?

Organic Molecule 4: Proteins

ENZYMES
▪Enzymes are re-usable.

▪ Once enzymes break down a substrate, they can move on to break

down more substrates.

▪ The enzyme is not changed by the reaction.

How do enzymes speed up chemical reactions?

Organic Molecule 4: Proteins

ENZYMES
▪How Enzymes speed
up reactions:

▪ Activation energy: the
amount of energy
needed to start a
reaction.

▪ Enzymes lower the
activation energy
needed to start the
reaction.

Organic Molecule 4: Proteins

Steps of Enzyme Function:
1.

Enzyme attaches to specific substrate at an active site.

2.

Substrate fits into the enzyme like a key fits into a lock.

3.

The enzyme quickly breaks down the substrate.

4.

The substrate is released as products.

5.

The substrate cannot be re-used but the enzyme is

re-usable and goes on to work on another substrate.

What is a denatured enzyme?

Organic Molecule 4: Proteins

ENZYMES

Denatured Enzymes: enzymes
which have lost their specific
shape, therefore do not function
properly or at all.

Ways to Denature an Enzyme:
1.

Change the pH. (Place
enzyme in an acid or base)

2.

Increase the temperature.

Denaturation

What are real world application of enzymes?

Enzymes : Real World Applications

●

Enzymes have several real world applications:
○

Human body
■

Breathing: expelling toxins from the body

■

Digestion: lipase, proteases, amylases, pepsin, lactase

○

Laundry detergent

○

Clothing (jeans)

○

Food preparation: meat tenderizers

Enzymes : Real World Applications

●

Lack of specific enzymes can lead to diseases such as
○

Albinism

○

Gout

○

Lactose intolerance

○

PKU

○

Tay Sachs Disease