Connect!

•If you eat a pizza, what does your body do to it? •Why?•Why are chemicals necessary for life?•What does digestion mean?•Why do you have to digest your food?•How do plants get their food?

Processing Chemicals

• Chemicals are necessary because they compose structures. In addition, chemicals must be processed in different ways to maintain homeostasis.

Organisms are constantly taking in chemicals as well as releasing chemicals.

Once chemicals are inside an organism they are changed in different ways.

• Unfortunately, we can’t always use chemicals the way they exist.

When you eat food or inhale oxygen your body uses these substances in chemical processes that keep you alive.

We use the following processes to change chemicals:

1. Digestion

• when we eat food the molecules are too big to enter our cells; as a result, our digestive system changes the larger molecules into smaller molecules

Large Digested to Small

Carbohydrates simple sugars (glucose)

Proteins amino acids

Lipids fatty acids and glycerol

Chunk Time!

• What do living things need to survive?• Why do the chemicals need to be

changed?• Name the 4 processes that change

chemicals.• Define digestion. Why is it necessary?• Name the 3 large molecule types, and

what they are digested into.

2. Synthesis

• after digestion you have small molecules in your cells; some of these molecules will be put together to form larger molecules to make structures, hormones, and enzymes

Synthesis is

the opposite

of digestion.

3. Respiration•as mentioned previously, after digestion you have small molecules such as glucose in your cells. Some of this glucose combines with oxygen in the mitochondria of cells to release energy needed to run the cell. This energy is stored in ATP.

4. Photosynthesis

•plants and algae use light energy to convert simple inorganic compounds into food which is organic

• What do plants need?

water + light + CO2

• What do plants make?

food (glucose) + O2

Chunk!

• Define synthesis. Why is it necessary?• What happens during respiration?• Where does respiration occur?• What is the energy molecule?• Define photosynthesis.• Explain what happens to a steak when you

eat it.

Connect!• What does a red face on a person

indicate?

• How do people with pools test for pH?

• How does pH paper work?

Indicators

• Indicators are chemicals that change color to indicate the presence of another chemical. pH paper is an example.

• There are many other indicators available…we will use 4 other indicators in bio this year.

Benedict’s Solution

• Indicates glucose

• Is bright blue

• Heat to boiling

• Turns brick red if glucose is present

Benedict’s Solution

Lugols’s Iodine Solution

• Indicates starch

• Is reddish brown

• Turns black if starch is present

Biuret Solution

• Indicates protein

• Is light blue

• Turns pink/purple if protein is present

Brown Paper

• indicates lipid

• rub on brown paper

• leaves a grease spot if lipid is present

Chunk

• Define indicator.• Name the indicator, it’s start and end colors, and what it

tests for…*lipids*glucose*protein*starch

• What indicators would test positive for a cheeseburger? For grilled tuna? For potato?

• If you order an Italian sub for take-out, what will the wrapper look like when you get home, and why?

• Name your favorite food, tell what organic molecules are in it, and how you would test for them.