ENZYMES & DIGESTION

What is occurring during digestion?

CHEMICAL REACTIONS!!!!

What is a chemical reaction?

reactant + reactant product

reactant product + product

reactant + reactant product + product

What are some other ways that we see chemical reactions represented?

We can graph the energy involved in a chemical reaction.

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Reactants

Products

Time

What do we start with in a chemical reaction?

What do we end with in a chemical reaction?

In order for the reaction to begin, we need some ENERGY!!!!

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reactant

Products

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This graph is the same reaction with an enzyme present.

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What was the effect of having an enzyme present for the reaction?

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Comparing Reactions Which line would represent a reaction without an enzyme present?With an enzyme present?

ENZYMES aka: Catalysts

A type of protein that speeds up chemical reactions by lowering the activation

energy.

Enzymes are specific. Enzymes work like a

lock and key. Specific enzymes

work with a specific chemical reaction.

We call the reactants of that reaction

substrates.

enzyme

substrate(reactant)

How does it work? The substrate binds to an active

site on the enzyme.Only a certain substrate fits into

the active site!

Match the substrates to their enzyme based on the “lock & key” model.

When the substrates bind, the chemical reaction occurs, and the

product is released.

What happens to the enzyme?The enzyme remains unchanged

& ready for the next set of substrates.

Enzymes work most efficiently within a certain range of temperature and pH!

Temperatures outside the range can change the shape

A pH value outside the range will cause the enzyme to change shape and be less efficient

WHY?

When an enzyme loses its shape it is said to be denatured.