1. BIOCHEMISTRY

2. REVIEW OF ATOMIC STRUCTURE Atom: smallest unit of matter Element: composed of only one type of atom Molecule: smallest unit of compound Compound: substance made of more than one type of atom Ion: an atom that is missing electrons-has + charge. An atom that has gained electrons has a - charge. (Why?) Covalent bond-bond where atoms share electrons Ionic bond-bond where electrons are transferred

3. WATER HAS SPECIAL PROPERTIES Cohesion Adhesion High specific heat Ice floats Universal solvent

4. WATER’S SPECIAL PROPERTIES ARE THE RESULT OF HYDROGEN BONDING Water is a polar molecule Water has polar covalent bonds WITHIN the molecules This means that the electrons are not shared equally between the oxygen and hydrogen atom; the oxygen atom pulls them more This causes the ends of the molecule to be slightly charged A hydrogen bond is the attraction BETWEEN water molecules that results as a factor of the different charges on the ends of the molecule

5. FRAYER FOLD #1 ON PROPERTIES OF WATER Cohesion High Specific Heat Define Why important to life? Ice Floats Define Adhesion Define Why important to life? Properties of water due to H bonding

6. FRAYER FOLD #2 ON WATER IS THE UNIVERSAL SOLVENT This is important because: Define Solute: Polarity of the water molecules makes it the universal solvent because: Define Solvent: Water is the universal solvent

7. COHESION AND ADHESION Cohesion is when water molecules are attracted to each other due to hydrogen bonding. This results in surface tension Adhesion is when water molecules are attracted to another substance, like the walls of a tube or paper towel Both of these properties are important to plants. This is how water moves up the tubes inside a plant. The water molecules stick to each other and to the walls of the tube. Evaporation from the leaves pulls the string of water up. Transpiration-cohesion-tension theory

8. WATER HAS A HIGH SPECIFIC HEAT Water resists changes in temperature Moderates climate Moderates body temperatures Body is 60% water Helps keep cell temperatures in the normal range

9. ICE FLOATS When water is a liquid, the molecules can get close to each other as they slide past. When the temperature (kinetic energy) drops, the water molecules slow down and lock into place “at arms length” along the hydrogen bonds. This means that ice is less dense than liquid water and floats This is important because bodies of water freeze from the top down, insulating the organisms underneath from the cold temps above the ice.

10. WATER IS THE UNIVERSAL SOLVENT This is due to the polarity of the water molecule. Water can pull apart other molecules by attracting the portion of the molecule to be dissolved away from other parts of the molecule. Lower left of foldable

11. WATER IS A POLAR SUBSTANCE Water molecules have charged ends; this is called being polar. Some substances, like oils, are not polar. Their charges are evenly distributed within the molecule. Polar and nonpolar substances do not mix because the polar substances are more attracted to each other than to the water. This is why oil and water do not mix.

12. ACIDS AND BASES The water molecule itself can dissociate or come apart into H+ and OH- ions. In pure water, the proportions of these ions are equal. (neutral) If you add a substance that causes more H+ ions, you have an acid. If you add a substance that causes more OH- ions, you have a base. pH goes from -1 to 14; pH= -log H+

13. BE ABLE TO RECOGNIZE FORMULAS AND STRUCTURES FOR THESE BASIC MOLECULES NaCl

14. END OF PART ONE OF THIS LECTURE

15. MACROMOLECUES AKA BIOMOLECULES

16. CARBON IS SPECIAL Carbon-based molecules are the foundation of life Carbon can form 4 covalent bonds-it can form a great variety of molecules Carbon atoms can form straight chains, branched chains, and rings Basis of organic chemistry

17. Name of macromolecule Function Examples Monomer name Polymer name Macro- molecules Name of macromolecule Function Examples Monomer name Polymer name Name of macromolecule Function Examples Monomer name Polymer name Name of macromolecule Function Examples Monomer name Polymer name Frayer Fold

18. 4 MAIN TYPES OF MACROMOLECULES Carbohydrates Lipids Proteins Nucleic acids

19. MONOMERS AND POLYMERS Biomolecules can be monomers or polymers Monomer is the basic building block Polymer is a chain of monomers Analogy: pearl=monomer; string of pearls=polymer

20. REACTIONS OF BIOMOLECULES Dehydration Synthesis Hydrolysis

21. CARBOHYDRATES Sugars and starches C:H:O proportions are 1:2:1 Examples: Glucose, sucrose, fructose (sugars) Cellulose (fiber) (plant cell wall) Glycogen (the way sugar is stored in the liver) Starch (potatoes, flour) Monomers are simple sugars or monosaccharides Polymers are polysaccharides Used for energy and cell structures

22. LIPIDS Do not have monomers and polymers C, H, and a little O Composed of 2 basic parts: head and tail Important kinds Triglyceride (fats) Phospholipid (make up cell membrane) Steroids Fatty acids Used for energy, protection, insulation

23. PHOSPHOLIPIDS AND CELL MEMBRANE STRUCTURE  Hydrophilic  “water-loving”  Polar, charged molecules  Ionic substances, substances with polar covalent bonds  Hydrophobic  “water-fearing”  Nonpolar, uncharged molecules  Nonpolar covalently bonded substances  The outer and inner part of the cell membrane is composed of POLAR phosphorus-containing heads  The inside of the membrane is composed of nonpolar fatty acid chains. The phospholipid molecules arranged according to the polar (hydrophilic) ends and the nonpolar (hydrophobic ends) with the water in the environment of the cell.

24. PROTEINS Monomers are amino acids Polymers are polypeptides 2 or more polypeptides fold into a protein Enzymes, cell structure Contains C, H, O, N and sometimes S Bonded with covalent bonds called peptide bonds

25. NUCLEIC ACIDS Monomers are nucleotides Polymers are polynucleotides Atoms CHONP DNA or RNA Transmission of hereditary information The order of the nucleotides is a code Nucleotide

26. IDENTIFY THESE MOLECULES:

27. END OF PART 2 OF THIS LECTURE

28. ENZYMES HOW ENZYMES WORK

29. CHEMICAL REACTIONS Bonds break and form during chemical reactions. It takes energy to break bonds. Chemical equilibrium happens when both the reactants and the products are formed at the same rate. reactantsproducts

30. REACTION ENERGY Activation Energy is the energy needed to get the reaction started. Compare endothermic reactions with exothermic reactions in regards to the energy of the reactants vs. the products.

31. ENZYMES Biological catalysts Catalysts lower the activation energy of a reaction This allows chemical reactions to occur under tightly controlled conditions Enzymes are proteins (and sometimes RNA)

32. LOCK AND KEY MODEL OF ENZYME ACTIVITY Enzyme structure is important because each enzyme’s shape allows only certain reactants to bind to the enzyme. The specific reactants are called the substrate. The lock and key model explains how enzymes work to bring substrates together. It also explains how the structure of the enzyme/substrate complex can exert an effect on the bonds of the substrate(s) thus lowering activation energy.

33. FACTORS THAT AFFECT ENZYME ACTIVITY pH Temperature pH and temperature can affect bonding within the protein molecule (polypeptide chain) that forms the shape of the enzyme…Since shape is important for the lock and key model and changes in pH and temperature affect shape….this affects the activity of the enzyme. Sucrase Animation