What happens to the food that we eat?

IT BREAKS DOWN INTO….Carbohydrates

Proteins

Fats

NUCLEIC ACIDS!

How does this happen?

• The changes that food molecules undergo are called reactions

• Reactions happen all the time in our body

• For a reaction to occur there has to be a certain amount of energy

Lactose Intolerance

• What does it mean to be lactose intolerant?

Lactose Intolerance

• What does it mean to be lactose intolerant?

– Being lactose intolerant means you are missing a protein that helps you digest the lactose sugar

– Since your body cannot break down the sugar, then you can get sick

Enzymes

• Enzymes are proteins that help molecules react with one another

– Ex: Lactase is the enzyme that breaks down lactose

Demo Time!!!

• I put yeast (the stuff you use to make bread) and hydrogen peroxide in this graduated cylinder

• Yeast contains an enzyme catalase that helps break down hydrogen peroxide into two different molecules- water and oxygen!

• What are we seeing????

Enzymes

• Enzymes are catalysts that speed up chemical reactions

• This works by lowering the amount of energy needed for a reaction to occur

• The amount of energy needed for a reaction to occur is called the activation energy

Enzymes – super special proteins

Enzymes speed up chemical reactions. They are also called catalysts.

Almost every reaction in your body is controlled by an enzyme!

Enzymes

• Each enzyme has an active site where a molecule can bind

• The molecule that binds to the enzyme is called the substrate

Enzyme specificity• Enzymes are specific to a particular reaction

• Each enzyme binds to one particular substrate

How does the environment affect enzymes?

• Extremely high temperatures or acidic environments can damage enzymes

What happens when an enzyme is denatured?

What does this mean?

• It means that each enzyme operates best at a certain temperature and pH

AMYLASE: breaks down starch in your mouth and stomach

LIPASE: breaks down fats

PEPSIN: breaks down proteins