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Key Questions:

•What are the major chemicals in living things?

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1. Characteristics of Proteins

•Proteins are organic molecules. They contain carbon, hydrogen, oxygen and nitrogen , and sometimes sulfur.

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2. Examples of Proteins• What parts of people

are mostly made of protein?

1. ________________2. ________________3. ________________

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1.Muscle

2.Hair

3.Nails

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•Did you eat any protein for breakfast?

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•Food Sources of Protein

•Meat: Beef, Pork, Poultry, Seafood•Dairy products (milk cheese, yogurt, cottage cheese)•Beans •Nuts•Soy beans and tofu

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Why do we need protein in our diets?

•Our bodies cannot make all the amino acids needed.

•We need to get 8 amino acids from our diet

•We call these the 8 essential amino acids

8 essential amino acids

• Isoleucine• Leucine• Lysine• Methionine• Phenylalanine• Threonine• Tryptophan• Valine

• Muscles• Blood, Muscles, Hormones• Herpes, triglycerides• Hair, skin• Depression• Collagen, tooth enamel• Depression• muscles

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•Plant material does not contain the 8 essential amino acids

•People who are vegetarians must eat a combination of beans and rice to obtain all the essential amino acids

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3. Uses of Proteins•Structural-

They serve as the building and binding materials of living things.

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•Most cell structures are made from proteins

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•Growth and Repair

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•Transporting material

•Ex. Hemoglobin transports oxygen in blood cells

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•Movement

•Ex. Collagen is a protein that forms tendons, ligaments, and cartilage

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• Enzymes• Control

rate of reaction and regulate cell processes

• Ex. Insulin lowers blood sugar

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• A catalyst that lowers the amount of energy needed for a reaction to occur.

• Almost every cellular reaction has an enzyme

What happens if you don’t have a certain enzyme?

• If you are lacking an enzyme, you aren’t able to break down certain proteins.

• For example, if you are lactose intolerant, you are missing the enzyme lactase.

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4. Structure of Proteins• Building blocks are amino

acids.• There are over 20 different

amino acids.

• Cells combine amino acids in different ways to form thousands of different

proteins.

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• Macromolecules –ProteinsAmino acids form chains that can fold and spiral and make complex protein structures.

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• General Design

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5. Unique Property of Proteins

•How are the amino acids in proteins like letters in a word?

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•How many letters in the alphabet? ____

•Letters make _____•Words can be big or little.

•Unlimited # of words.

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•How many amino acids? ____

•Amino acids make _______•Proteins can be big or little.•Unlimited # of _________

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Making Connections

On the side of a Diet Coke can it says WARNING: Contains Phenylalanine. Why would a person need to worry about an increase of an essential amino acid in their diet?