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Chapter 6.3 Life Substances

Chapter 6.3 Life Substances. The role of carbon in organisms. Carbon atoms have four electrons available for bonding in their outer most energy level Stable Carbon formation = 4 covalent bonds Carbon can bond with other elements & with other carbon atoms

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Chapter 6.3 Life Substances

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  1. Chapter 6.3Life Substances

  2. The role of carbon in organisms • Carbon atoms have four electrons available for bonding in their outer most energy level • Stable Carbon formation = 4 covalent bonds • Carbon can bond with other elements & with other carbon atoms • Single Bonds- covalent bonds formed w/2 electrons shared btwn atoms • Represented by • Double Bonds- covalent bonds formed w/4 electrons shared btwn atoms • Represented by • Triple Bonds- covalent bonds formed w/6 electrons shared btwn atoms • Represented by

  3. The role of carbon in organisms • Carbon atoms bond to each other and can form: • Straight chains • Branched chains • Rings • Chains or rings can have almost any # of carbons or other elements on them • Many Carbon formations = lots of carbon structures possible • Cmpds with same chemical formula can have different 3-D structures

  4. The role of carbon in organisms • Isomers-compounds with same chemical formula but different 3-dimensional structures • Draw Glucose & Fructose-Note the same chemical formula, different structures • Carbon cmpds vary in size • Biomolecules –large organic cmpds • Ex/Proteins, Fats, Nucleic Acid, Carbohydrates

  5. The role of carbon in organisms • Polymer-def- a large molecule formed when many smaller molecules bond together • How are Polymers formed? • Condensation Rxn • How are Polymers broken down? • Hydrolysis Rxn

  6. The structure of Carbohydrates • Carbohydrates- a biomolecule composed of carbon, hydrogen, and oxygen with a ratio of 2H : 1 O : 1 C • Monosaccharide- a simple sugar • Ex/ Glucose & fructose • Disaccharide-a two sugar carbohydrate • How does a disaccharide form? • Ex/Sucrose (table sugar) -formed when glucose & fructose combine via condensation rxn

  7. The structure of Carbohydrates • Polysaccharides = Largest carbohydrate molecules composed of many monosaccharids • Ex/Polysaccharide Examples • Starch-consist of branched chains of glucose units • Used as energy storage by plant cells and as food reservoirs in seeds & bulbs • Glycogen-consists of highly branched glucose polymer • Used by mammals to store energy in the liver • Cellulose-consists of long chains of glucose units that are linked together in a chain-link fence arrangement. • Used to form cell walls of plants and gives plants structural support

  8. The structure of Lipids • Lipids-def-pg.160-large biomolecules that are made mostly of carbon and hydrogen with sm. Amt of oxygen • Ex/ fats, oils, waxes, & steroids • Insoluble in water (meaning they don’t dissolve in water)-b/c these molecules are nonpolar &  are not attracted by water molecules • Lipids generally contain: • 3 Fatty acids (long chains of carbon&hydrogen) • 1 glycerol molecule

  9. The structure of Lipids • Types of Fatty Acids • Saturated-each carbon in the chain bonded to 1 other carbon by single bonds • Unsaturated- each carbon in the chain is bonded by a double bond • Polyunsaturated-fatty acids with more than one double bond

  10. The structure of Lipids • Importance of Lipids: • Needed for propering fxn’ing of org • Cells use it for energy storage • Cells use it for insulation & protective coverings • Lipids major component of cell membrane (phospholipids)

  11. The structure of Nucleic Acids • Nucleic acid-def-pg.163-a complex biomolecule that stores cellular information in the form of a code. • Nucleotides-def-pg.163-nucleic acids are polymers made up of smaller subunits called nucleotides which consists of the following elements: • Carbon -Oxygen • Hydrogen -Nitrogen • Phosphorous • Parts of a Nucleotide: • Nitrogenous base • Simple sugar • Phosphate grp

  12. The structure of Nucleic Acids • DNA-def-pg.163- Deoxyribonucleic acid-master copy of an organism’s information code • RNA-def-pg.163-Ribonucleic acid, nucleic acid that forms a copy of DNA for use in making proteins

  13. The Structure of Proteins • Proteins are essential to all life • Protein Components • Proteins-def-pg.160- a lrg, complex polymer that is composed of H2, O2, N2 & S. • Amino acids-def-pg.161- Basic building blocks of proteins = amino acids (A.A.) • 20 common A.A.  various diff combos can = thousands of proteins

  14. The Structure of Proteins • How are A.A.s linked together? • –H from the amino grp & -OH grp from the hydroxyl grp are removed to form a peptide bond • –H & -OH come together to form a water molecule • Peptide bond-def-pg.161-the covalent bonds that are formed btwn A.A.s • Video-hippocampus video • http://www.hippocampus.org/homework-help/Biology/Biomolecules_Structure%20and%20Function%20of%20Proteins.html

  15. The Structure of Proteins • Protein Structures & Fxns: • Protein Structure • Proteins come in lrg varieties of shapes & sizes • A.A. sequence & # that make up protein are imp in determining a protein’s shape • 3-D shape of protein is imp to a proteins’ fxn • Proteins imp in: • Contracting of muscle tissue • Transporting O2 in bloodstream • Providing immunity • Regulating other proteins • Carrying out chemical rxns & metabolism (enzymes) • Provide structure for tissue & organs

  16. The Structure of Proteins • ALL ENZYMES ARE PROTEINS BUT NOT ALL PROTEINS ARE ENZYMES • Enzyme-def-pg161- a protein that changes the rate of a chemical rxn • Involved in nearly all metabolic processes. • Parts of the Enzyme: • Substrates-reactants in an enzymatic rxn • Active sites-the small part of the enzyme where the substrate binds • Activity of enzyme depends on: • temperature • ionic conditions • pH of surroundings • concentration of enzyme

  17. The Structure of Proteins • How enzymes work? Action of Enzymes • Enzymes act on a specific substrate • Each substrate fits into an active site (lock & key theory) • Enzyme may can shape a little to fit with substrate • Enzyme-substrate complex puts a stress on the substrate due to the binding of the substrate to the enzyme this facilitates the reaction • Once reaction is complete the products are released from the enzyme • Enzyme is unchanged and retains its original shape & can now carry out more enzymatic rxns-process repeats Video-Yahoo Videos-”how enzymes works”- www.zo.utexas.edu & Enzyme Animation

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