2. PROTEINS Workhorse of the Cell

3. PROTEINS Which foods are high in protein?

4. What are proteins?

5. You are protein! Proteins account for 50% of dry mass.

6. Proteins are the workhorses of the cell. Chemical reactions Structure Transport Movement DNAPROTEINS CELLS Communication Proteins do all the work! Protection Regulation

7. Chemical Reactions - Enzymes --- control the rate chemical reactions in a cell. Proteins have many different functions: Protection – Antibodies --- combat bacteria and viruses. Transport - Hemoglobin --- transports oxygen to all cells in all parts of the body. Movement – Muscle --- actin & myosin contract and expand allowing organisms to move Regulation - Hormones --- insulin regulates the concentration of sugar in the blood Communication – Receptor Proteins --- relays signals between cells

8. Other proteins provide structure and support: Skin, ligaments, tendons, cartilage, bone, and arteries contain collagen. Upper layer of skin, hair, nails, feathers, scales, hoofs, and horns are composed of keratin. Pigment in skin, hair, and eyes contain melanin.

9. A protein is composed mainly of carbon, hydrogen, oxygen, and nitrogen.

10. A protein is a macromolecule composed of monomers of amino acids. amino acid amino acid amino acid amino acid amino acid monomer amino acid Polymer Protein

11. Proteins Chain of amino acids amino acid

12. There are 20 different amino acids.

13. All amino acids have a similar structure. —N——N— H H H | —C— | C—OH || O R hydrogen Amino group Carboxyl group R group

14. All amino acids have a similar structure. —N——N— H H H | —C— | C—OH || O R same Different Here

15. How do these amino acids differ? They differ in their R group.

16. Proteins differ in the number, type and order of amino acids. amino acid amino acid amino acid amino acid amino acid Protein = = amino acid How many amino acids are in these proteins? Protein = amino acid amino acid amino acid amino acid amino acid amino acid amino acid amino acid amino acid 5 6 4 Proteins can differ in the number of amino acids.

17. amino acid amino acid amino acid amino acid amino acid Protein = = amino acid How many different amino acids are in these proteins? Protein = amino acid amino acid amino acid amino acid amino acid amino acid amino acid amino acid amino acid amino acid 2 3 5 Proteins can differ in The type of amino acids.

18. Protein = amino acid amino acid amino acid amino acid amino acid Protein = amino acid amino acid amino acid amino acid amino acid Protein = amino acid amino acid amino acid amino acid amino acid How many amino acids are in these proteins? ___ How many different amino acids are in these proteins? ___ Are these the same proteins? ___ How are these different proteins?_____________________ 5 3 no in their order of amino acids

19. ENZYMES - - - are Proteins Enzymes are extremely important proteins because they control all the chemical reactions that occur in our bodies.

20. Enzymes are catalysts. Catalysts are compounds that speed up chemical reactions.

21. Enzymes remain unchanged. Same - - - enzyme unchanged

22. Enzyme Active Site Products Substrate