Proteins

Have a protein bar or an egg! Protein contains the elements carbon, hydrogen, oxygen and nitrogen. Proteins are used by your body for growth and repair of tissues. They also are very important to the chemical reactions in your cells. You can get lots of protein from animal products like: meat, poultry, fish, and dairy products, but also from plant products like nuts, grains and beans.

Proteins are made from smaller chemical units called amino acids. There are twenty different types of amino acids which connect in different ways in a long chain to make a protein. Proteins don't just remain as a long chain, they fold into very complicated molecules in order to do their work in your body. The different amino acids are often represented by a letter as you'll see in the video.

Proteins from animal products are called complete proteins because they have all the essential amino acids necessary to build protein. Proteins from plant products are called incomplete proteins because they are missing one or more essential amino acids. Vegetarians, people who do not eat animal products, combine a variety of plant products in order to get all the essential amino acids. Rice & beans is a g ood example!

The first video shows a protein with all the amino acids in a chain which then folds. Notice that sometimes you can see a letter on each amino acid.

media type="youtube" key="swEc_sUVz5I" height="364" width="445"  The second video shows a "receptor ( //receiving // ) protein" on the surface of a cell. It's like it's waiting for a call or a signal! The "signal protein" shows up and is received by the "receptor protein". The signal tells the cell to do something, to start some type of chemical reaction. The contact points, the places where the two proteins touch, turn a different color to show where the two proteins connect chemically. Notice how well they fit together. We definitely need good nutrition to make these important proteins.

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One protein you may have heard of is insulin. It is made up of 51 linked amino acids. Insulin is made in the pancreas and helps you body function by taking glucose from your bloodstream to your cells. Your cells use the glucose for making chemical reactions happen or //energy//. Watch the video to help you visualize insulin "at work".

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Assignments: 1. For this page use SQ4R:survey, question, read, recite, rewrite, review. 2. Are there any words you want to add to your notes? to the glossary? 3. Complete your notes for this page in your notebook. You may look at the note format page for help. 4. Complete the web outline for proteins in your notebook.