Chapter 6: The Chemistry of Life

1. Chapter 6: The Chemistry of Life Georgia Standards: The learner will identify the structure & function of the four major macromolecules (i.e., carbohydrates, proteins, lipids, nucleic acids). Essential Questions: How does the structure of a carbohydrate influence its function? What are the roles of carbohydrates in living things?

2. Why is Chemistry important to Biology? • Life depends on chemistry. • The first job of a biologist is to understand the chemistry of life.

3. Carbon Compounds & Organic Chemistry • What is organic chemistry? • Organic chemistry is the study of all compounds that contain bonds between carbon atoms.

4. 1.Carbon atoms have four valence electrons to make 4 bonds. 2. Carbon can bond with many elements including hydrogen, oxygen, phosphorus, sulfur, and nitrogen 3. Carbon atoms can bond to other carbon atoms 4. Chains of carbon atoms can even close upon themselves to form rings  Properties of Carbon Compounds 

5. What is a Macromolecule? • Many of the molecules in living cells are so large that they are known as macromolecules (large molecules) • Monomers + Monomers =polymersPolymerization - to form polymers.

6. Types of Macromolecules in Living Systems • Four groups of organic compounds found in living things are • Carbohydrates • Lipids • Nucleic acids • Proteins

7. Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1 : 2 : 1.   Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes. What are Carbohydrates?

8. Starches and sugars are examples of carbohydrates that are used by living things as a source of energy. Single sugar = monosaccharides (simple sugar) Glucose Galactose Fructose Carbohydrates

9. Polysaccharides (complex sugar) Forms when monosaccharides link together Animals store excess sugar as glycogen. Plants store excess sugar as starch. Cellulose Carbohydrates

10. Starch Glucose Go to Section:

11. Molecular Model Building • Use the molecular model kit to build glucose • Carbon = black • Oxygen = blue • Hydrogen = white • Electron bond = white plastic tube

12. #6 question to WS • The structural arrangement of C, H, and O in glucose, fructose, and galactose differs. This helps explain why different model shapes are used for each monosaccharide. • Molucules of monosaccharides may have the same molecular formula but differ in the 3D structure. This is called isomerism. Using the three models and structural formulas, describe isomerism in your own words.

13. Ticket out the Door • Frayer Model on Carbohydrates

14. Warm-up: • What properties of carbon explain carbon’s ability to form many different macromolecules? • Why do living things need carbohydrates?

15. Lipids can be used to store energy Form biological membranes Form waterproof coverings Steroid Hormones Pigments Examples: Body Fats Oils Waxes Steroids Testosterone Chlorophyll Cell membrane Lipid Function:

16. Lipids are made mostly from: Carbon, hydrogen, & oxygen atoms Monomers of fatty acids & Glycerol Many lipids are formed when a glycerol molecule combines with compounds called fatty acids. Lipid Structure:

17. Lipid Structure

18. Saturated Carbon-carbon single bonds All carbons are completely surrounded by hydrogen Solid at room temp Lard Unsaturated Carbon-carbon double or triple bonds All carbons are not completely surrounded by hydrogen. Liquid at room temp Olive oil Types of Lipids

19. Fats in Foods Lab • See Handout

20. Contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. Monomers of nucleotides 5-carbon sugar Phosphate group Base Nucleic acids store and transmit hereditary, or genetic, information. Ribonucleic acid (RNA) Deoxyribonucleic acid (DNA). Nucleic Acids

21. Nucleic Acid

22. Strawberry DNA Extraction Lab • See Handout

23. Made of carbon, hydrogen, nitrogen, and oxygen. Monomers = amino acids 20 different amino acids Proteins control the rate of reactions Regulate cell processes. Form bones and muscles. Transport substances into or out of cells Help to fight diseases. Proteins

24. Amino Acids Amino group Carboxyl group General structure Alanine Serine Amino Acids (monomers) are linked by peptide bonds to form proteins (polymers). Go to Section:

25. Proteins can have up to four levels of organization. Primary level is the sequence of amino acids in a protein chain. Secondary level is the amino acids within a chain can be twisted or folded. Tertiary level is when the chain itself is folded. Quaternary level is when two or more folded chains interact. Levels of Proteins

26. Structural: Collagen, Keratin, myosin, Functional: enzymes Examples:

27. Figure 2-17 A Protein Amino acids Go to Section:

28. Carbohydrates Lipids Nucleic acids Proteins Sugars and starches Fats and oils Nucleotides Amino Acids Carbon, hydrogen, oxygen Carbon, hydrogen, oxygen Carbon, hydrogen,oxygen, nitrogen, Carbon,hydrogen, oxygen, nitrogen, phosphorus Concept Map Carbon Compounds include Monomers of Monomers of Monomers of Monomers of which contain which contain which contain which contain Go to Section:

29. Checkpoint!!! • Name four groups of organic compounds found in living things. • Describe at least one function of each group of organic compounds. • What properties of carbon explain carbon’s ability to form many different macromolecules? • Explain why proteins are polymers but lipids are not.

30. Chapter 6: The Chemistry of Life Georgia Standards: Explain how enzymes (functional proteins) function as biological catalysts. • Essential Questions: • How does the enzyme-substrate complex work? • Why are enzymes important to living things?

31. A chemical reaction is a process that changes one set of chemicals into another set of chemicals. Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products. Chemical Reactions & Enzymes

32. Chemistry in Biology Chapter 6 6.2 Chemical Reactions Chemical Equations • Chemical formulas describe the substances in the reaction and arrows indicate the process of change. • Reactants are the starting substances, on the left side of the arrow. • Products are the substances formed during the reaction, on the right side of the arrow.

33. Chemistry in Biology Chapter 6 6.2 Chemical Reactions • Glucose and oxygen react to form carbon dioxide and water.

34. Chemistry in Biology Chapter 6 6.2 Chemical Reactions Balanced Equations • The law of conservation of mass states matter cannot be created or destroyed. • The number of atoms of each element on the reactant side must equal the number of atoms of the same element on the product side.

35. Chemistry in Biology Chapter 6 6.2 Chemical Reactions Energy of Reactions • Theactivation energy is the minimum amount of energy needed for reactants to form products in a chemical reaction.

36. Chemistry in Biology Chapter 6 6.2 Chemical Reactions • This reaction is exothermic and released heat energy. • The energy of the product is lower than the energy of the reactants.

37. Chemistry in Biology Chapter 6 6.2 Chemical Reactions • This reaction is endothermic and absorbed heat energy. • The energy of the products is higher than the energy of the reactants.

38. Chemical reactions that release energy often occur spontaneously Exothermic Feels warm to the touch Chemical reactions that absorb energy will not occur without a source of energy. Endothermic Feels cools to the touch Energy in Reactions

39. Enzymes are proteins that act as biological catalysts Functional protein Cells use enzymes to speed up chemical reactions that take place in cells, by lowering the activation energy (energy needed to start a reaction) Enzymes

40. Chemistry in Biology • It does not increase how much product is made and it does not get used up in the reaction. Chapter 6 6.2 Chemical Reactions Enzymes • A catalyst is a substance that lowers the activation energy needed to start a chemical reaction.

41. Effect of Enzymes Section 2-4 Reaction pathway without enzyme Activation energy without enzyme Activation energy with enzyme Reactants Reaction pathway with enzyme Products Go to Section:

42. Chemistry in Biology Chapter 6 6.2 Chemical Reactions • The reactants that bind to the enzyme are called substrates. • The specific location where a substrate binds on an enzyme is called the active site.

43. Chemistry in Biology Chapter 6 6.2 Chemical Reactions • The active site changes shape and forms the enzyme-substrate complex, which helps chemical bonds in the reactants to be broken and new bonds to form. • Factors such as pH, temperature, and other substances affect enzyme activity.

44. Enzymes are very specific. Enzymes must collide with enough energy so that old bonds can be broken and new bonds can be formed. Enzymes have an active site where the substrate (reactant) will bind. Activation energy is reduced Enzyme Action: How do enzymes do their job?

45. Enzyme Action Section 2-4 Enzyme (hexokinase) Glucose Substrates ADP Products Glucose-6- phosphate ATP Products are released Active site Substrates bind to enzyme Enzyme-substrate complex Substrates are converted into products Go to Section:

46. Chemistry in Biology Chapter 6

47. Classwork:Complete the Regulation of Enzyme Handout • pH • Temperature • Other proteins turn enzymes “on” and “off”

48. Checkpoint!!! • What happens to chemical bonds during chemical reactions? • Describe the role of energy in chemical reactions. • What are enzymes, and how are they important to living things? • Describe how enzymes work, including the role of the enzyme-substrate complex. • A change in pH can change the shape of a protein. How might a change in pH affect the function of an enzyme such as hexokinase?

49. Enzyme Lab • See Handout