1. Unit 3:CELLS Cellular Energy

2. Carbon Compounds

3. Objective What are the functions of each group of organic compounds?

4. Most of the compounds that make up living things contain carbon. In fact, carbon makes up the basic structure, or “backbone,” of these compounds. Each atom of carbon has four electrons in its outer energy level, which makes it possible for each carbon atom to form four bonds with other atoms. As a result, carbon atoms can form long chains. A huge number of different carbon compounds exist. Each compound has a different structure. For example, carbon chains can be straight or branching. Also, other kinds of atoms can be attached to the carbon chain. Section 2-3 Interest Grabber Life’s backbone

5. MethaneAcetyleneButadieneBenzene Isooctane

6. Macromolecules “giant molecules” Formed by a process called polymerization

7. Monomers Smaller units

8. Polymers Linked up monomers

9. Carbohydrates Compounds made up of carbon, hydrogen, and oxygen atoms usually in a ratio of 1:2:1 Main source of energy The monomers of starch are sugars

10. Single sugar molecules are called monosaccharides The large macromolecules formed from monosaccharides are known as polysaccharides

11. Starch Glucose

12. Lipids Made mostly from carbon and hydrogen atoms Used to store energy

13. Lipid Glycerol Fatty Acids

14. Proteins Macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen Proteins are polymers of molecules called amino acids

15. Amino Acids General structureAlanineSerine Carboxyl group

16. More than 20 different amino acids, can join to any other amino acid The instructions for arranging amino acids into many different proteins are stored in DNA Each protein has a specific role The shape of proteins can be very important

17. Proteins Amino Acids

18. Nucleic Acids Macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus Double Helix

19. Nucleotides Consists of 3 parts: 5-carbon sugar, phosphate group and nitrogen base Nitrogen Base 5-Carbon Sugar Phosphate group

20. 2 kinds of nucleic acids RNA (ribonucleic acids) – contains sugar ribose DNA (deoxyribonucleic acid) – contains sugar deoxyribose

21. Homework

22. 1.Name four groups of organic compounds found in living things 2. Describe at least one function of each group of organic compounds

23. 3. Compare the structures and functions of lipids and starches

24. Chemical Reactions and Enzymes

25. Objectives What happens to chemical bonds during chemical reactions? How do energy changes affect whether a chemical reaction will occur? Why are enzymes important to living things?

26. The Big Idea Living things are made up of chemical compounds Everything that happens to an organism is based on chemical reactions

27. Chemical Reactions A process that changes or transforms one set of chemicals into another

28. Reactants Elements or compounds that enter into a reaction

29. Products Elements or compounds produced by a chemical reaction

30. Example Reaction: Getting rid of carbon dioxide In the blood In the lungs CO 2 + H 2 0  H 2 CO 3 (carbonic acid) H 2 CO 3  CO 2 + H 2 O Released as you breathe

31. Energy in reactions Energy-Absorbing Reaction Energy-Releasing Reaction Products Activation energy Activation energy Reactants

32. Activation Energy The energy that is needed to get a reaction started

34. Enzymes Some chemical reactions are too slow or have activation energies that are too high to make them practical for living tissue These chemical reactions are made possible by catalysts

35. Catalyst Substance that speeds up the rate of chemical reactions Work by lowering a reactions activation energy

36. Enzyme Biological catalysts Speed up reactions in cells Very specific Named for the reaction is catylzes Enzyme names always end in - ase

37. Reaction pathway without enzyme Activation energy without enzyme Activation energy with enzyme Reaction pathway with enzyme Reactants Products

38. Substrates The reactants of enzyme catalyzed reactions The active site of the enzyme and the substrate have complementary shapes Fit like a lock and key

39. Enzyme Action Enzyme – substrate complex

40. Glucose Substrates ATP Substrates bind to enzyme Substrates are converted into products Enzyme-substrate complex Enzyme (hexokinase) ADP Products Glucose-6- phosphate Products are released Active site

41. Regulation of Enzyme Activity Enzymes are affected by any variable that affects chemical reactions 1.pH 2.Temperature 3.Concentration of enzyme

43. Homework

44. 1.What happens to chemical bonds during chemical reactions 2. Describe the role of energy in chemical reactions

45. 3. What are enzymes, and how are they important to living things?

46. 4. Describe how enzymes work, including the role of the enzyme substrate complex

47. 5. A change in pH can change the protein. How might a change in pH affect the function of an enzyme such as hexokinase (hint: think about the analogy of the lock and key)