Do Now

1. Get out HW, Turn in lab from yesterday into the bin

2. Which macromolecule(s) functions in short term energy and structure?

1. Explain the difference between Benedict’s and Biuret’s. (More than color change)

Chemical ReactionOccurs when bonds are broken or formed to

create a new substance

Reactants Products

Enzymes ReviewEnzymes are proteins; made up of amino acids held

together by peptide bonds

Enzymes ReviewRegulates the chemical reactions of the cell

Enzyme Characteristics

1. Biological Catalysts

What is a Catalyst?

Catalysts speed up chemical reactions

Ex: What do you do to help sugar dissolve faster in

tea?

Enzymes and Reactions

Enzymes and Reactions

Activation Energy – Amount of energy that reactants must absorb before a chemical reaction will start

Enzymes lower the activation energy.

Enzymes and Reactions

Endergonic Reaction: Free energy is absorbed from the surroundings

Enzymes and Reactions

Exergonic Reaction: Chemical reaction where there is a net release of free energy.

Example of Enzymes as CatalystsAmylase: Enzyme in mouth that breaks down

carbohydrates

If you put a saltine cracker in your mouth and let it “sit”, it will eventually taste sweet

Enzymes Characteristics

2. Have an active site; binding site for substrates

Enzyme Characteristics

3. Enzymes are site specific; One

enzyme = One job

Determined by active site

How Enzymes Work

Enzyme; Catalyst

Substrate;Reactant

Active Site

Product

Enzyme-Substrate Complex

1. Substrate matched the active site of the enzyme2. Enzyme-substrate complex forms; Enzyme molds around the substrate for a reaction3. Enzyme releases the product; Enzyme remains unchanged.

Types of Chemical Reactions

Synthesis (Anabolic in living organisms) – 2 or more chemicals combine to form a more complex product.

Types of Chemical Reactions

Decomposition (catabolic in living organisms) – A compound is broken into smaller chemicals

What does this have to do with ME????? Who cares about enzymes?

Lactose is a Disaccharide (2 sugars)

found in milk

Lactase is an enzyme that breaks down lactose

What does lactose get broken down into by lactase?

Fill in the following terms into the enzyme diagram below:

LactaseGlucoseLactose

Galactose

What’s happening in us?

What is Lactose Intolerance?Lactase is not

present to break down the lactose.

The sugar just builds up

inside.

What’s happening in us?

Effects of Lactose Intolerance*

Bloating, Pain/Cramps in Belly, Noise in Belly, Gas, Diarrhea

Lactose Intolerance Worldwide

Lactose Intolerance in Ethnic Groups

What to do if you are Lactose Intolerant?

Do Now

1. What is the purpose of the active site?

2. What would happen if the active site lost its shape?

Environmental Effects on Enzymes

1. Temperature* • High

Temperatures can denature enzymes

• Denature means lose shape (active site).

Environmental Effects on Enzymes

1. Temperature • Low

Temperatures cause enzymes to move slowly

• Decreasing

enzyme activity

Environmental Effects on Enzymes

2. pH •Dramatic changes in the pH of a solution can denature an enzyme •Decreasing enzyme activity

DigestionNerves

Digestion Papaya’s