Chapter 3: Water and Biological Molecules

1. Chapter 3: Water and Biological Molecules

2. Human use Drink it Cook in it Bathe in it Harness it for power Use it to dispose of wastes Swim in it 71% of the Earth’s surface is water 66% of body weight in humans 3.1 The Importance of Water

3. Aqueous solution Water is the solvent breaks down the solute that has been put into it Fig. 3.1 solute NaCl + Solvent H2O NaCl attracted to the polar water molecule NaCl ion separate from each and become surrounded with water molecules Na+O and Cl+H What is a Major player in Many of Life’s Processes

4. Water Surrounds the ions in order to keep them from getting back together Keeps the ions evenly dispersed=solution Effect of water molecule on NaCl

5. Ice floats because it is less dense then water The cooling of water makes the water molecules slow their motion. When their motion is slowed they are able to form the maximum number of hydrogen bonds with each other. Result water molecules are spaced further apart when frozen. Water structure gives it many unusual properties

7. 2. Water has a great capacity to absorb and store heat. Water is a great insulator frozen, liquid, or gas Due to Specific heat the amount of energy required to raise the substance by 1 degree Celsius. Water has a high specific heat What does this mean? It takes a lot more energy to raise the temperature of water by 1 degree Celsius. Water VS Ethyl Alcohol Water takes twice as much energy to raise the temperature by one degree. As a result water releases heat only when the environment surrounding it is cooler.

8. How is this accomplished? Hydrogen bonds Weak but have a huge effect when they occur in large numbers The large amount of molecules makes it harder to break these chemical bonds These bonds give water molecules another unique charateristicCohesion The ability of the water molecules to stay together. During plant transpiration water is brought from the roots to the leaves where evaporation occurs by the Cohesive ability of water.

9. 3. Water’s cohesion gives it surface tension Surface tension (water meets air) water molecules below the surface are equally attracted to in all direction to other water molecules. At the surface where water meets air it has no attraction to air The latter cause the “beading” of water droplets and allows small organisms to move across the surface w/out sinking.

10. There are molecules that do not dissolve in water nonpolar covalent molecules Polar covalent molecule molecules made up of Hydrogens and carbons (H+C)hydrocarbons CH4 Methane, Petroleum,… Oils are not dissolved by water because it doesn’t have a charge for the water molecule to bond with What water cannot do

11. Hydrophilic (“water-loving”) Cpds that will interact with water Hydrophobic (“water-fearing”)Cpds that do not interact with water Very important helps form cell barrier cell membrane Two Important terms: Hydrophobic and Hydrophilic

12. Carbon is the starting ingredient for life Life is based on Carbon Just like baking the starting point is always flour Why is carbon used as a starting ingredient for life? Has only 4 e- in the outter shell but needs a total of eight for maximum stability. Obtains maximum stability by creating covalent (sharing e-) bonds Organic Chemistry a branch of chemistry devoted to the study of cpds. That have carbon as their cnetral element. 3.3 Carbon is the central element in Life

13. Straight Chain Carbons Methane CH4 PropaneC3H8 Carbons link together forming a straight chain carbon molecule ButaneC4H10 Fuel found in cigarette lighters Can have two forms Isomers molecules that are the same in their chemical formula, but differ in the spatial arrangement of their elements How does carbon link up with itself and other carbons?

14. Carbon Rings Benzene C6H6 Found in petroleum products Note the three sets of double bonds the atoms involved are sharing two pairs of e-. Glucose C6H12O6 Blood Sugar

15. Carbons can become specialized with the addition of certain atoms Functional groups a group of atoms that confers a special property on a carbon based molecule Analogy Wrench Socket wrench vs. an Allen wrench Ethane Flammable gas Remove a H and add a functional group  hydroxyl -OH= ethyl alcohol Any –OH that is added to a hydrocarbon group (C-H) an alcohol is formed Not only has the molecular function changed but also the polarity The strong electronegativity of the oxygen in the –OH (hydroxyl group) ethyl alcohol is now polar and can bond with other charged or polar molecules 3.4 Functional Groups • Ethane • Nonpolar • Flammable gas • Ethyl alcohol • Polar • alcohol Remove a H and replace with a functional group –OH

17. Four groups of Organic cpds Carbohydrates Lipids Proteins Nucleic Acids All made up of smaller subunits Carbohydrates Simplest subunit glucose (monosaccharide) Many monosaccharides starch (polysaccharide) Monomer glucose a small molecule that can be combined with other similar or identical molecules to make a polymer Polymer a large molecule made up of many simpler or identical subunits 3.5 Carbohydrates

18. Carbohydrates Always contain Hydrogen, Carbon, and Oxygen Contain twice as many hydrogen atoms as oxygen atoms Glucose C6H12O6 Carbohydrates: From Simple Sugars to Cellulose

19. Monosaccharide simple sugars glucose Glucose can bind to other monosaccharides to form complex carbohydrates Fig. 3.10 Maltose Formed by two monomers of glucose The link between the monomers is a single oxygen atom The formation of Maltose requires for the removal of two hydrogens and 1 oxygen from two glucose molecules=Maltose +water Note: This is a reversible process Functional group –OH is present Building Blocks of Carbohydrates

20. Monosaccharide Glucose Fructose Deoxyribose Disaccharide Sucrose Lactose Maltose -ose sugar Kinds of Simple Carbohydrates

21. Polysaccharide polymers of carbohydrates Poly Many Saccharide sugar http://pslc.ws/macrog/kidsmac/tooncell.htm Cellulose cell wall Most abundant carb in the world Trees, cotton, leaves, and grasses In humans major source of insoluble fiber (whole grain and fresh fruits) Helps food move through the digestive tract 2. Chitin Arthropods, Crustaceans and Fungi Structural support Strength and shape for organisms 3. Starch Plants use for storage Potatoes, rice, carrots, and corn 4. Glycogen Animals use for storage Stored in muscle cells Complex Carbohydrates are Made Up of Chains of Simple Carbohydrates

22. Lipids Insoluble in water Made up of H, O, and C Have more hydrogen then Carbohydrates Glycerol Exist as; Oils Fats Cholesterols Hormones (testosterone and estrogen) Not a polymer No single structural unit is common to all lipids Due to their insolubility they can Serve as internal containers Store energy Provide information 3.6 Lipids

23. Glyceride: Most common lipid Two parts Head alcohol (glycerol) Tail fatty acida molecule found in many lipids that is composed of a hydrocarbon chain bonded to a carboxyl group 4 22 Carbons Stearic Acid Fatty acid found in animal fats Long Fatty Acid tail Head Functional Carboxyl Group COOH- One Class of Lipids is the Glycerides

24. Triglyceride lipid molecule formed from three fatty acids and a glycerol -OH (alcohol) part of Glycerol combines with COOH- (carboxyl) part of fatty acid chain.= one glyceride Glycerol has 3 –OH+ (3 COOH + Fatty acids)=Triglyceride R=Hydrocarbon Chains (C-H) Glycerol Triglyceride

25. 1 Glycerol +3 Stearic fatty acids= Tristearin An exception to the rule Normally, 1 Glycerol may have 3 different types of fatty acids attached to it to form a triglyceride 2 Fatty acids diglyceride 1 Fatty acid monoglyceride Butter is composed of several fatty acids Triglyceride Tristearin

26. Three different types of fatty acids Palmitic Saturated No double bonds Oleic Monounsaturated One double bond Linoleic Polyunsaturated More then one double bond * Double bonds creates “kinks” in the molecules. Saturated and Unsaturated Fatty Acids

27. Saturated (in Fatty Acids) with Hydrogens Oils are turned into Saturated fats by adding Hydrogens (hydrogenation) this process enabled the liquid oils to be used as a solid form Saturated fats has been linked with heart disease Increase the amount of cholesterol in body Cholesterol lodges in the arteries of the heart Saturated Fatty Acid No double bonds between Carbons of the hydrocarbon chain Monounsaturated Fatty acid One double bond between carbon atoms Polyunsaturated Fatty Acid Two or more double bonds between carbon atoms Fatty Acids from Solids to Liquids

28. Lipids Storage Triglyceride Energy Broken down to glycerol and Fatty acids VS Carbohydrates Storage Glycogen Energy Glucose Energy Use and Storage in Lipids

29. Steroids lipid molecule that has a central element in their structure, four carbon rings Different steroids have different side chains attached to it no polymers A second class of lipids is the steroids

30. Phospholipid( a charged lipid molecule composed of)= Glycerol + Phosphate group+ 2 Fatty acid tails Phosphate group 1 phosphorus atom surrounded by 4 Oxygen atoms Phospholipid dual nature Hydrophilic head Phosphate (Charged=polar) Hydrophobic tail  Fatty acid Phospholipids make up the membranes of cells A Third Class of Lipid is the Phospholipid

31. Importance of Proteins Almost every chemical reaction that takes place in living things in enabled by a particular kind of protein called an enzyme Each Enzyme has a particular task An animal cell may contain up to 4,000 different types of enzymes Other functions of proteins: Form tissues Transport molecules Allow muscles to contract Cells to move Some hormone are made from proteins If you remove water from the cell about half of the weight of a cell is accounted for by proteins 3.7 Proteins

32. Amino Acids Monomers of Proteins Composed of  Carboxyl COOH (acid) Amine group NH2 A central Carbon A side chain The side chain (R) makes each amino acid unique There are only 20 Amino Acids that make up all protein The order of amino acids in a polypeptide chain makes different proteins Polypeptides Chain 1030 Amino Acids Can fold up in a specific three dimensional manner to form a Protein Made up of hundreds of amino acids strung up together and folded Two or more peptide chains can make up one protein Proteins are made from Chains of Amino Acids

34. Proteins fold up in a specific way Chemical forces between the Amino acids determine the three dimensional shape of a protein Protein conformation, extremely crucial Insulin Released by the pancreas Moves through the bloodstream “Latches onto” to muscle cells Its presence allows glucose to get into the muscle and provide energy Able to latch onto cell by protein receptor If both insulin and receptor (proteins) do not have the proper shape Glucose is not taken up by the muscle cell. DIABETES Insulin is used medically to treat some forms of diabetes mellitus. Patients with type 1 diabetes mellitus depend on external insulin (most commonly injected subcutaneously) for their survival because of an absolute deficiency of the hormone. Patients with type 2 diabetes mellitus have insulin resistance, relatively low insulin production, or both; some type 2 diabetics eventually require insulin when other medications become insufficient in controlling blood glucose levels. Shape is critical to functioning of all Proteins

35. Primary Structure simply it sequence of amino acids Electrochemical bonding and repulsion forces act on this structure and the result is a folded up protein Secondary structure once the forces begin to operate on the Amino Acid sequences Alpha helix corkscrew shape Beta pleated sheet accordion shape Silk Protein can be made of one or the other or both Tertiary structure Three dimensional shape Quaternary structure two or more polypeptide chains Four Levels of Protein Structures

36. PH Alcohol Works great as a disinfectant alters the shape of protein in bacteria Temperature Raw VS cooked Egg or meat Proteins Can Become Undone

37. Lipoproteins Combination of lipids and proteins Transport protein  fats Type depends on amount of lipid content Lipid is less dense then protein High Density Lipoprotein (HDL) Carry cholesterol away from the outlying cells to the liver Low Density Lipoprotein more lipids then protein Carries cholesterol to the outer lying tissues Bring about heart attacks Glycoproteins Combination of proteins and carbohydrates Receptors in cells just like the insulin one Hormones Proteins released from the cell Lipoproteins and Glycoproteins

38. Nucleic Acids Information Storage devices of cells Long polymers of Nucleotides Each is composed of a three carbon sugar+ nitrogenous containing base + phosphate group Two Types of Nucleic Acids DNA Deoxyribose nucleic acid RNA Ribonucleic Acid RNA VS DNA Ribose sugar where 4/5 Carbons bond to a hydroxyl group (-OH) DNA, Hdroxyl group is replaced with a hydrogen atom RNA uses nucleotides Adenine, Uracil, Cytosine, and Guanine DNA uses nucleotides Adenine, Thymine, Cytosine, and Guanine RNA is a single strand of nucleotides DNA consist of two nucleotide strands wound around each other in a double helix 3.8 Nucleotides and Nucleic Acids

40. Essays Acid Rain: When Water is Trouble From Trans Fats to Omega 3’s: Fats and Health