1. Proteins
GT Biology

2. 1. sometimes contain sulfur and phosphorous
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

3. B. Proteins function as
1. Structural parts of cells & body
tissues
Ex: Cartilage, bones, muscles

4. 2. Hormones – chemical messengers
3. Antibodies – protect body from foreign substances
Enzymes – speed up chemical reactions (end in “-ase”)
Protection
ex: hair, turtle shell, horns, hooves

5. Sources of Proteins as food
Eggs
Dairy
Beans and Nuts
Meat
Fish

6. II. The building blocks of proteins are amino acids (AA’s)
Central carbon atom bonded to:
1. 1 Carboxyl group
2. 1 amino group
3. 1 hydrogen
4. 1 side chain ?

7. There are 20 different kinds of amino acids (usually end in “-ine”)

8. III. How proteins are formed
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

9. B. The bond between two amino acids is a peptide bond
water
dipeptide

10. H2O

11. C. Dipeptide – a molecule composed of 2 amino acids

12. D. Polypeptide – a molecule composed of more than 2 amino acids

13. The smallest protein has 50 amino acids
The largest protein has over 100,000 amino acids

15. V. The structure of a protein determines its function
Coils or helixes (one chain)
Pleated sheets (One chain)
Globular (many chains together)
globular

16. 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

17. Construct a Venn diagram comparing
Lab book entry
Construct a Venn diagram comparing
and contrasting Carbohydrates, Lipids,
and Proteins.
carbo
What they all
have in
common.
What the
Two have in
common
Unique features
lipid
protein