2. Biology10/15 Homework: finish lab guide and 2.4 wkst Turn in graphi

3. Section 2.3 Biomolecules What are the four types of biomolecules?

4. Today you will: Learn about each type of biomolecule Learn how to test for the presence of each biomolecule in different food substances.

5. Questions to discuss In this lab you will put different food sources in a test tube to test for the presence of various macromolecules. Why will one of your test tubes be filled with distilled water? What is the dependent variable? What is the independent variable?

6. Biomolecules Molecules are either inorganic compounds or organic compounds –Organic-has carbon –Inorganic-no carbon Why is carbon so special? –It can form 4 bonds with other atoms. It loves to COVALENTLY BOND! –It can form single, double, and triple bonds.

7. Biomolecules There are 4 types of biomolecules in our bodies –Carbohydrates –Lipids (fats) –Proteins –Nucleic acid (DNA) These are large molecules (polymer) that are made up of smaller building blocks (monomers) Polymers are made of monomers. http://www.phschool.com/scie nce/biology_place/biocoach/bi oprop/monomers.htmlhttp://www.phschool.com/scie nce/biology_place/biocoach/bi oprop/monomers.html

8. Proteins Elements: C, H, O, N, or S (sulfur) Structure: look for N or S What do they do –Hemoglobin in your blood that carries oxygen –Muscles, tendons, hair –Defend body from microorganisms –Control chemical reactions-enzymes –Carry out almost all of the body’s everyday functions Building block-amino acids

9. Proteins A protein’s shape is very important You change the shape of a protein, you change the function or lose the function

10. Testing for proteins You will use a biuret reagent It will turn a blue violet color in the presence of a protein. You will add each substance to a test tube and then add a few drops of biuret reagent.

11. Carbohydrates Elements-C, H, O Function: Main source of energy, gives plants tough structure Examples: sugars and starches, glycogen, sucrose, glucose, cellulose Shape-rings connected Building Block- monosaccharide or simple sugars (glucose)

12. Different types of carbohydrates Based on size –Monosaccharide-one sugar Glucose, galactose (found in milk), fructose (found in fruit) –Disaccharide-two sugars lactose –Polysaccharide-many sugars Cellulose-makes plants have a rigid structure Glycogen-animal starch

13. Two carbohydrate tests-starch and simple sugars Starch –Iodine will turn black or purple in the presence of starch Benedict’s solution –Add substances to tube with benedict’s solution –Heat for 3 to 5 minutes to look for color change –The redder the more simple sugar (glucose) present –Will form a percipitate

14. Lipids (Fats) Not a polymer –Why? Elements-C, H, O Has the most energy but we can’t consume tons of fat; part of membranes; insulation Structure-long chain of carbons attached Examples: cholesterol, wax, steroids, oils Building Block-fatty acids and glycerol

15. Saturated vs. Unsaturated Saturated-bad for you; causes cholesterol problems, clogged arteries; solid at room temperature; lard Unsaturated-liquid at room temperature; not as bad for you; olive oil, canola oil, peanut oil Trans fat-type of unsaturated; causes coronary heart disease

16. 2 ways to test for lipids Brown paper bag –Substance will leave an oil spot if present Sudan 4 test –Substance will turn red

17. Nucleic Acids Tell your cells how to function Contains the genetic information DNA (deoxyribose sugar) and RNA (ribose sugar) Building blocks: nucleotides Elements: C, H, O, N, P