Proteins GT Biology I Proteins are compounds made
Proteins GT Biology
I. Proteins are compounds made of carbon, hydrogen, nitrogen, and oxygen A. Proteins 1. sometimes contain sulfur and phosphorous 2. can have the ending “-in” ex: insulin, gastrin, hemoglobin 3. are very versatile 4. make LIFE possible
B. Proteins function as 1. Structural parts of cells & body tissues Ex: Cartilage, bones, muscles
2. Hormones – chemical messengers 3. Antibodies – protect body from foreign substances 4. Enzymes – speed up chemical reactions (end in “-ase”) 5. Protection ex: hair, turtle shell, horns, hooves
Sources of Proteins as food Eggs Dairy Beans and Nuts Meat Fish
II. The building blocks of proteins are amino acids (AA’s) A. Central carbon atom bonded to: 1. 2. 3. 4. 1 Carboxyl group 1 amino group 1 hydrogen 1 side chain ?
B. There are 20 different kinds of amino acids (usually end in “-ine”)
III. How proteins are formed A. Proteins are formed by dehydration synthesis (sound familiar? ) *link amino acids together One AA loses an “OH”, one loses an “H” forming a dipeptide and water. This can continue to link many AA together = a protein
B. The bond between two amino acids is a peptide bond water dipeptide
H 2 O
C. Dipeptide – a molecule composed of 2 amino acids
D. Polypeptide – a molecule composed of more than 2 amino acids
1. The smallest protein has 50 amino acids 2. The largest protein has over 100, 000 amino acids
V. The structure of a protein determines its function A. Coils or helixes (one chain) B. Pleated sheets (One chain) C. Globular (many chains together) globular
How do you test for a Protein? The Biuret test: * add a small amount of Biuret solution to the sample. If it contain protein, it will turn purple
Lab book entry Construct a Venn diagram comparing and contrasting Carbohydrates, Lipids, and Proteins. carbo What the Two have in common lipid What they all have in common. Unique features protein
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