1. Big Idea The work of each cell is done primarily by proteins. Since there are hundreds of thousands of “chores” for a cell to do, there are hundreds of thousands of proteins.

2. Proteins

3. What is a protein?  One of four types of macromolecule Proteins fold in unique ways so that each one has a particular 3-D structure.

4. Building blocks of proteins  Amino acids

5. Amino acids bond together Peptide bond:

6. How many different kinds of proteins?  Hundreds of thousands! 20 amino acids – like 20 letters, arranged in different orders to form words In proteins, the sequence of amino acids (“words”) averages 300 amino acids (“letters”) long

9. Where do we get the amino acid building blocks? Essential amino acids— You must get them in your diet every day. Animal products provide complete proteins (with all amino acids). Vegetarians have to make sure to eat foods that contain all amino acids: like rice or corn with beans. Non-essential amino acids are made by the body.

10. What do all these proteins do?  Virtually every task in every cell of your body!

11. Structural  Hair, nails and skin

12. Structural  Muscle and nerves

13. Structural  Membranes

14. Enzymes  Enzymes catalyze chemical reactions in cells: make them happen more quickly and with less energy needed

15. http://www.youtube.com/watch?v=Pvg pk75us18

16. Enzymes Enzymes end in –ase Examples  lactase – breaks down lactose (milk sugars)  diastase – digests vegetable starch  sucrase – digests complex sugars and starches  maltase – digests disaccharides to monosaccharides (malt sugars)  glucoamylase – breaks down starch to glucose  protease – breaks down proteins found in meats, nuts, eggs, and cheese  lipase – breaks down fats found in most dairy products, nuts, oils, and meat  cellulase – breaks down cellulose, plant fibre; not found in humans

17. Enzymes  Our cells could not function without thousands of enzymes—a major reason why protein is an all- important molecule

18. Transport molecules  Hemoglobin

19. Transport molecules  Cytochromes

20. Messenger proteins  Insulin

21. Antibodies

22. Proteins make you you!

23. http://learn.genetics.utah.edu/content/ begin/dna/tour_protein.html