Chapter 5: Lipids, Nucleotides, Carbohydrates

1. Chapter 5: Lipids, Nucleotides, Carbohydrates

2. A way to generate diversity of organic compounds is to form long chains out of simpler subunits.

3. Huge organic compounds are called macromolecules. These are compounds made by linking together many copies of smaller units called monomers. Macromolecules are also called polymers (many parts) because they are many of many monomers (one part).

4. 3 Huge molecules made by linking many monomers together are called: • Fatty acids or nucleic acids • Macromolecules or polymers • Sugars or nucleotides

5. 4 & 5. Macromolecules form when: • Polymerization links monomers together into polymers • Macromolization links polymers into monomers

6. #6 Cells contain these kinds of organic compounds in the form of macromolecules Carbohydrates—made of monomers called monosaccharides or simple sugars (question 9) Lipids—made of monomers called fatty acids Nucleic acids—made of monomers called nucleotides Proteins—made of monomers called amino acids.

7. Condensation (dehydration synthesis) or hydrolysis • Monomers are linked by dehydration synthesis via specific enzyme proteins • Polymers are broken by hydrolysis. http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html http://www2.nl.edu/jste/lipids.htm Lipids form ester links between fatty acids and glycerol Proteins form peptide bonds by hydrolysis (the primary structure forms) Sugars form glycosidic linkages Nucleotides form phosphodiester bonds between c5 PO4 groups & the c3 OH group of the upstream nucleotide

8. Lipids: hydrophobic macromolecules that are either polymers made of fatty acid monomers OR are steroids primarily composed of hydrophobic cyclic hydrocarbons Saturated fatty acids—long hydrocarbon chain with no C=C & a terminal carboxyl group Unsaturated fatty acids—as above but with C=C Steroids—this form (3 6-member & 1 5-member cyclic hydrocarbons connected—side chains vary (examples testosterone, estrogen, anabolic steroids, etc)—used as hormones

9. Triglycerides—fats: a form of lipid form when 3 fatty acid monomers are joined by dehydration synthesis (aka condensation) to 1 glycerol molecule used to store energy, insulate from shock & cold

10. Phospholipids: 2 fatty acid chains linked to one glycerol, along with one hydrophilic phosphate group containing side chain major components of cell membranesamphipathic—have a nonpolar nature (the 2 fatty acid tails) and a polar end (the phosphate group)

11. Carbohydrates—polymers of simple sugar (monosaccharide) monomers. Used to store energy or build structures or as protein modifiers in glycoproteins or as cell identification tags in glycolipids General formula of a monosaccharide CnH2nOn Often circularized but switch from linear to circular forms Contain many -OH groups and sometimes –CHO groups Linked by condensation synthesis, forming glycosidic linkages Note system for numbering C’s relative to the ether linkage, going clockwise. C6H12O6 to know: glucose, fructose, mannose, galactose, dextrose Glucose is the primary source of energy used by nearly all cells on earth

12. Monosaccharides to know Ribose (in RNA As shown or w/ H not –OH On C2 in DNA) Glucose & isomers of glucose C6H12O6

13. dwb.unl.edu

14. Disaccharides to know:

15. Polysaccharides to know • Starch—stores energy in plants • Glycogen—stores energy in animals Alpha-1-4 glycosidic linkages make starch & glycogen coil • Cellulose—forms rigid cell walls in plants and some protists Beta-1-4 glycosidic linkages make cellulose form cables that can stack to build rigid cell walls http://www.absorblearning.com/media/attachment.action?quick=11z&att=2723 note error—shows cellulose formation http://bcs.whfreeman.com/thelifewire8e/content/cat_040/0304001.html http://www.absorblearning.com/media/attachment.action?quick=11y&att=2721

16. Starch α1-4—food storage for plantsglycogen α1-4—food storage for animalscellulose β1-4—cell wall fibers

17. Nucleic acids—polymers of nucleotides: used to store (DNA), express (RNA), & regulate (RNA) genetic information. Tri-phosphate nucleotides also store energy used by cells to do work. Note the counterclockwise labeling of the C’s starting with the in-chain ether linkage of the ribose sugar.

18. Lipids, Lipids: Polymers made from fatty acid monomers OR steroids Mostly made of hydrocarbon chains (C and H) Hydrophobic because the C—C & C—H bonds are nonpolar (C & H have similar electronegativity)

19. Lipids are the class of polymers (macromolecules) that cells use to: • Build coverings on cells (membranes) • Store energy as fats and oils • Protect and insulate the body (waxes, fat around the organs) • Make most hormones and cholesterol (from steroids) • Classes: fats, oils, waxes, steroids

20. Nucleic Acids The molecules that control heredity (ability of cells to divide so that they can reproduce new cells like themselves. Include Deoxyribonuclease (DNA) and Ribonuclease (RNA)

21. DNA (nucleic acid polymer) is a double helix made of nucleotide monomers. It controls heredity & cell function from within the nucleus.

22. DNA is a double helix with anti-parallel, complementary strands made of A, T, C, and G http://bcs.whfreeman.com/thelifewire8e/content/cat_040/0304001.html

23. Another class of nucleic acid is RNA. RNA is a copy of one gene in DNA. RNA carries the instructions for syntheisis of one protein.

24. Ribonucleic acid RNA is less stable than DNA, exits the nucleus, and normally exists as a single strand. During gene expression, it is synthesized to complement one side (template strand) of DNA.

25. Nucleic Acids—The monomers that make up nucleic acids are known as: • Amino acids • Fatty acids • monosaccharides • Nucleotides • Simple sugars

26. Nucleic Acids Nucleotides consist of what 3 parts? • Hydrocarbon tail, oxygens, phosphate groups • C, H, & O in a 1:2:1 ratio • Ribose, phosphate group, nitrogenous base • Carboxyl group, amino group, R group

27. Nucleic Acids What is the function of nucleic acid? • Controls cell traits • Instructions for making protein • DNA, RNA • Stores energy • None of the above • More than one above

28. Nucleic Acids What are the 2 kinds of nucleic acids? • Starch and glycogen • DNA and RNA • Saturated & unsaturated • Hydrophobic & hydrophilic • Ionic and covalent

29. The proteins of most immediate importance in cells; they are the “workers” of the cell. Proteins are monomers of amino acids. Their possible roles include: Regulators of other proteins Receptors to allow cells to receive information Signals like hormones and growth factors that allow cells to send messages to other cells. Transporters controlling movement of substances in and out of cells or membrane bound organelles Energy storage Structural elements like cytoskeletal proteins ENZYMES that control which chemical reactions occur by increasing rates & lowering energy barriers for only particular chemical substrates

30. #25, page 19 RSGWhat is not one of the 4 roles that that proteins usually play in organisms? • Store heredity information & pass it to new cells • Serve as enzymes that speed up reaction • Build structures in the body, like collagen in hair • Serve as receptors and hormones that allow cells to communicate with each other

31. Proteins are polymers of amino acids.Interactions between the R groups (the variable parts—shown in pink & blue on the left picture) of the amino acids causes the protein to fold into a 3D shape necessary for function.When a protein is denatured (loses its shape), it no longer functions. http://www.accessexcellence.org/RC/VL/GG/ecb/ecb_images/04_02_polypeptide_backbone.jpg http://images.google.com/imgres?imgurl=http:/ Campbell’s biology textbook, 7th edition, pearson, prentice hall publishing.

32. #23, page 19 RSGProteins contain what kinds of atoms? • C and H only • C, H, and O • C, H, O and N • C, H, O, N, and P

33. #24, page 19 RSGProteins are polymers of molecules called? • Monosaccharide monomers • Amino acid monomers • Fatty acid monomers • Nucleotide monomers • steroids

34. How do we to protect ourselves from food poisoning (infection by bacteria,protists,fungi or viruses)?Cook it: denature proteins by heating atoms (>vibration) to break between R groupsCure it with salt: break ionic bonds between + acidic R groups & – basic R groupsPickle it: +acidic & -basic R groups form ionic bonds w/ bases,acids in pickle solution instead of each otherShake it: break bonds (like making meringues)With proteins—especially enzymes—denatured, the infecting cells can’t carry out chemical reactions or other protein functions, so they die.

35. Stop here for Chapter 5 test Tuesday, Sept. 18, 2012 • On Friday, September 19, 2012, we will watch the video on proteins (proteins: structure and function) at this website. http://www.learner.org/resources/series61.html or http://www.learner.org/vod/vod_window.html?pid=815 • A transcript and list of questions to direct you to important information is included in the links for organic chemistry at my teacher website at www.mayfieldschools.org • In class Friday, we will also classify amino acids as hydrophilic, hydrophobic, charged (+ basic or – acidic, according to R group structure).

36. Watch these animations about proteins http://wps.aw.com/wps/media/access/Pearson_Default/1663/1703422/login.html Username: mayfieldstudent1 Password: scienceaccount2009 Go to chapter 5 on the top bar, then go to Concept 5.4 Proteins have many structures, resulting in a wide range of functions   Double click to watch Activity: Protein Functions  Double click to watch Activity: Protein Structure   Proteins are polymers made of amino acid monomers • Also called polypeptides because peptide bonds link amino acids • Have optimal 3D shape that controls their function (it depends on the order of the amino acids and on the conditions like pH, temperature) • Are denatured & lose function by breaking (shaking, pH too high or low, too hot or cold, too salty, etc) attractions between amino acid R groups that hold them into their optimal shape at optimal conditions • Include many types of proteins—called the workers of the cell. • Transport proteins that allow materials to move in and out of cells • Receptor proteins that allow cells to use hormones to communicate • Enzymes that catalyze (speed up, lower energy needed) chemical reactions • Hormones and other signal proteins that convey information to other cells • Structural proteins used to build parts of organisms (e.g., collagen in hair)