Enzymes

● Enzymes are PROTEINS.
● They act as catalysts to speed

up a reaction by lowering the
activation energy.

What are enzymes?

What else do i need to know about enzymes?

●Usually end in “ase”

●Are made up of amino acids

●Are not consumed during the reaction (reusable)

●Lower the activation energy required for the reaction to

occur

●Have specific shapes→ globular

●Are substrate specific

Enzyme

Breakdown

Location

Lactase

Lactose (milk sugar)

Small intestine

Lipase

Lipids (fats)

Pancreas/Stomach

Sucrase

Carbohydrates (sucrose)

Small intestine

Amylase

Carbohydrates (starch)

Mouth (saliva)

Protease

Proteins

Pancreas/Small Intestine

Pepsin

Proteins

Stomach

Most enzymes usually end in “ase”

How do enzymes work?

Two Binding Theories:

•Lock and Key Model- Enzyme-substrate fit like a lock and key
•Induced fit Model- Enzyme shape can change slightly to fit
substrate.

Enzymes lower the amount of activation energy needed
for the reaction to occur..

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return to this slide to continue the enzyme
presentation!

Enzyme Activity Can Be Affected by:

1.Environmental Conditions

•Temperature and pH

2. Activators (increase enzyme activity)

•Cofactors/coenzymes

3.Inhibitors (decrease enzyme activity)

•Competitive Inhibitor-

•Noncompetitive Inhibitor-

4..Concentration of Substrate

•(i.e. protein concentration)

Involved in:
●

Cell regulation

●

Muscle contraction

●

Active transport

●

Digestion

●

Metabolic pathways

●

Industrial application
○

(food processing, meat tenderizing, genetic
engineering)

Enzymes are essential to maintaining

homeostasis in living organisms.

How do enzymes

work?

A: Enzymes lower the activation energy needed for a reaction
to occur

B: Enzymes increase the activation energy needed for a
reaction to occur

A

B

What is the role
of an enzyme?

A: Enzymes slow down chemical reactions for the maintenance
of homeostasis in living organism.

B: Enzymes speed up chemical reactions for the maintenance of
homeostasis in living organism.

A

B

How do enzymes

work?

A: Enzymes repeat the process since they are reusable/recycled

B: Enzymes get consumed in the reaction.

A

B

The End