Organic Molecules in Cells: Carbon, Carbohydrates, Lipids, Proteins, Nucleic Acids

1. Entry Task – 3 points • What is a cell? • What is an Organic Molecule? • What is a macromolecule?

2. Carbon Atoms Are Essential for Life • What is an Organic Molecule? • It is a molecule that contains carbon and hydrogen atoms. • Other than water, most molecules in a cell are carbon-based. • What is a macromolecule? • A large molecule built from many smaller molecular units into chains • Can be composed of hundreds (or millions) of atoms • Cells • Build macromolecules for specific uses • Break down macromolecules for energy and other uses

3. Carbon Atoms Are Essential for Life • What are the 4 basic types of Organicmolecules found in all living organisms? • Carbohydrates • Lipids • Proteins • Nucleic Acids

4. Carbon Atoms Are Essential for Life • Carbohydrates • an organic compound made up of C, H, and O • Provide Energy:Glucose (C6H12O6 )is the primary energy source for cells • Provide Structure: CelluloseandChitin • Simple sugars (glucose) are soluble in water = hydrophilic

5. Carbohydrates Complex carbohydrate (e.g., starch) Glucose (simple sugar)

6. Carbohydrates (con’t) • Produce and store energy • Glucose is used by cells as the main source of energy. Glucose is a simple carbohydrate. • Complex carbohydrate = simple carbohydrates joined together into larger molecules • Starch : CC formed by plants to store energy • Cellulose : structural CC found in cell walls • Glycogen= CC formed by animals to store energy • Structural roles: • cell wall of plant cells (cellulose) • exoskeleton of some insects (chitin)

7. Carbon Atoms Are Essential for Life • Lipids • not soluble in water = hydrophobic • Provide Energy storage (fats) • Components of Cell Membranes • Chemical signals (steroids)

8. Lipids • Also called Fats • Made up of C, H, O • Provide long term storage of energy and carbon • Fats produce more than 2x as much usable energy as glucose • Used in the construction of cell membranes (with proteins) • Phospholipid bilayer • Fatty acids are the fats in your diet • Omega-3 and Omega-6 fatty acids are essential

9. Structure of Fatty Acids

10. Lipids • Steroidsare lipids where the carbon skeleton forms four rings. • Circulate in your body as chemical signals (estrogen, testosterone) • Cholesterolis the starting point for your body to produce other steroids

11. Stop & Think (pg. 269) • Using the atomic model kit, build a model of the ring form of glucose on p. 267. • Sketch your model in your science NB. • Label your model and write the chemical formula beneath the model. • Animals store energy reserves as lipids. Plants store energy reserves as starches. What is the advantage of storing energy in lipids? • Build a saturated fatty acid model • Build an unsaturated fatty acid model

12. Proteins & Amino Acids • Read “Proteins & Amino Acids” p. 269 • Take notes (Cornell or Outlining)

13. Proteins • Present in the cells in large amounts • Contain H,O,N,C • Molecules composed of amino acids • DNA stores the info to make all proteins an organism requires for life • Shape and function of a protein molecule is determined by the order of amino acids • 20a.a.’s are commonly found in proteins • humans produce 9 of the 20 • 11 are essential and must be obtained from food • Plant, animal, and bacteria cells all produce protein

14. How do we get the amino acids we need ? • Meats are complete and contain all of the essential amino acids • Vegetables - low or are missing essential amino acids • Digestion breaks down proteins into amino acids for use by cells to build the different proteins your body needs

15. Proteins • Functions of Protein • structural components of cells • messengers and receivers of messages (receptors) between cells • Help defend against disease • Enzymes • Specialized protein molecules that assist reactions occurring in cells

16. Nucleic Acids • Made of nucleotides • Sugar + nitrogen base + phosphate group • C,H,O,N,P • Store and transmit hereditary information • Carry the instructions for cell processes • DNA and RNA

17. Stop & Think • What are the functions of organic molecules in cells? • Describe how it is possible for so many different proteins to exist. Elements Organic Molecule Functions in Cell

18. Stop & Think • Describe how it is possible for so many different proteins to exist. • Many foods are soluble in water so that you can digest them. Many parts of your body are not soluble in water. Yet both food and body parts are made from carbohydrates, lipids, proteins, and nucleic acids. How can this be?

19. Carbon Atoms Are Essential for Life • What are the 4 basic types of Organic molecules found in all living organisms? (Continued) • Proteins • Responsible for almost all of the day-to-day functioning of organisms • Provide structure: membranes, hair, skin, muscles, skeleton • Messengers: convey and receive messages from one cell to another • Enable chemical reactions in cells: enzymes • Nucleic Acids • Carry the instructions for all cell processes • Store and transmit genetic information