Molecules of life intro


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Molecules of life intro

  1. 1. The Molecules of Life Chapter 3
  2. 3. The Simplest Hydrocarbon <ul><li>Methane = Carbon + Hydrogen </li></ul>
  3. 4. Organic Molecules <ul><li>A cell is mostly water but the rest consists mainly of carbon based molecules </li></ul><ul><li>Compounds that contain carbon are called organic compounds </li></ul><ul><li>Carbon has the ability to form the large, complex diverse, molecules necessary for life functions </li></ul><ul><li>Why are carbon atoms so versatile as molecular ingredients? </li></ul>
  4. 5. Carbon Chemistry <ul><li>Carbon a versatile atom has 4 electrons in an outer shell that holds 8 </li></ul><ul><li>- carbon can share its electrons with other atoms to form up to 4 covalent bonds </li></ul><ul><li>Carbon can use its bonds to attach to other carbons </li></ul><ul><li>to form an endless diversity of carbon skeletons </li></ul><ul><li>- each carbon in an organic molecule can branch off in up to 4 directions </li></ul><ul><li>Carbon atoms of organic molecules can also bond with other elements (hydrogen, oxygen, nitrogen) </li></ul>Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings
  5. 6. Variations in Carbon Skeletons <ul><li>Simplest organic compounds are hydrocarbons </li></ul><ul><li>Hydrocarbons consist of carbon and hydrogen </li></ul><ul><li>Each C atom forms 4 bonds; each H atom forms 1 bond </li></ul>Fig 3.2
  6. 7. Larger Hydrocarbons <ul><li>Main molecules in the gasoline we burn in our cars </li></ul><ul><li>Hydrocarbons of fat molecules provide energy for our bodies </li></ul>Fig 3.4
  7. 8. Functional Groups <ul><li>Each type of organic molecule has a unique 3-dimensional shape that defines its function in an organism </li></ul><ul><li>- the molecules of your body recognize one another based on their shapes </li></ul><ul><li>The unique properties of an organic compound depend not only on its carbon skeleton but also on the atoms attached to the skeleton </li></ul><ul><li>- these atoms are called functional groups </li></ul><ul><li>Functional groups behave consistently from one organic molecule to another </li></ul>
  8. 9. 4 Important Functional Groups <ul><li>Many biological molecules have 2 or more functional groups </li></ul><ul><li>How do cells make large molecules out of smaller organic molecules </li></ul>
  9. 10. Size of Molecules <ul><li>Monomers </li></ul><ul><ul><li>Molecules used as subunits to </li></ul></ul><ul><ul><li>build larger molecules (polymers) </li></ul></ul><ul><li>Polymers </li></ul><ul><ul><li>Larger molecules that are chains of monomers </li></ul></ul><ul><ul><li>May be split and used for energy </li></ul></ul>
  10. 11. Building Blocks <ul><li>On a molecular scale, many of life’s molecules are gigantic </li></ul><ul><li>- biologists call them macromolecules (macro = ‘big’) such as DNA, carbohydrates, proteins </li></ul><ul><li>Most macromolecules are polymers </li></ul><ul><li>- polymers are made by stringing together many smaller molecules called monomers </li></ul><ul><li>- cells link monomers together through a dehydration reaction (removes a molecule of water) </li></ul><ul><li>Organisms break down macromolecules (digestion) </li></ul><ul><li>- cells do this by a process called hydrolysis (hydro = ‘water’ lyse = ‘break’; to break with water) </li></ul>
  11. 12. Dehydration Reaction <ul><li>Synthesis – a polymer grows in length when an incoming monomer and </li></ul><ul><li>the monomer at the end of the existing chain contribute to the formation </li></ul><ul><li>of a water molecule, the monomers then replace their lost covalent </li></ul><ul><li>bonds with a bond to each other </li></ul>
  12. 13. Hydrolysis <ul><li>Breaking a polymer chain – hydrolysis reverses the process by </li></ul><ul><li>breaking down the polymer with the addition of water molecules, which </li></ul><ul><li>break the bonds between monomers </li></ul>
  13. 14. Biological Molecules <ul><li>There are 4 categories of large molecules in cells: </li></ul><ul><li>Carbohydrates </li></ul><ul><li>Lipids </li></ul><ul><li>Proteins </li></ul><ul><li>Nucleic Acids </li></ul>
  14. 15. Carbon-Carbon Macromolecules <ul><li>Aka: Organic Molecules </li></ul><ul><li>Fall into 4 groupings: </li></ul><ul><li>Carbohydrates </li></ul><ul><li>Lipids </li></ul><ul><li>Proteins </li></ul><ul><li>Nucleic Acids </li></ul>
  15. 16. Carbohydrates <ul><li>‘ Carbs ’ - from small sugar molecules in soft drinks to long starch molecules in pasta and potatoes </li></ul><ul><li>- serve as a primary source of dietary energy </li></ul><ul><li>- used as building material to form the body of a plant </li></ul><ul><li>Monosaccharides (mono = ‘one’, and sacchar = ‘sugar’) are simple sugars: </li></ul><ul><li>- glucose found in sports drinks </li></ul><ul><li>- fructose found in fruits </li></ul><ul><li>Monosaccharides glucose and fructose are isomers </li></ul><ul><li>- they have the same molecular formula, but their atoms are arranged differently </li></ul>
  16. 17. Glucose <ul><li>Monosaccharides, particularly glucose, are the main fuel that cells use for cellular work </li></ul><ul><li>Cells break down glucose molecules and extract their stored energy </li></ul><ul><li>- give off CO2 as waste </li></ul><ul><li>Monosaccharides also provide cells with carbon skeletons that can be used as raw material </li></ul>
  17. 18. Polysaccharides <ul><li>Long repeating chains of monosaccharides </li></ul><ul><li>Often used for Energy storage </li></ul><ul><li>Animals form Glycogen from glucose units </li></ul><ul><li>Stored in Liver and muscles </li></ul><ul><li>Plants also store glucose polysaccarides </li></ul><ul><li>Starch </li></ul>
  18. 19. Carbohydrate Complexity <ul><li>Monosaccharides : useable Energy </li></ul><ul><li>Disaccharides : transport form </li></ul><ul><li>Polysaccharides : Storage and structural forms </li></ul>
  19. 20. Lipids: Fats & Oils <ul><li>Insoluble in water, but soluble in oil </li></ul><ul><li>Examples include: </li></ul><ul><li>Oils (olive, corn…) </li></ul><ul><li>Waxes (bee’s, ear) </li></ul><ul><li>Fats </li></ul><ul><li>Lipids have two ends. </li></ul><ul><li>Hydrophilic – water loving head </li></ul><ul><li>Hydrophobic – water fearing tail </li></ul>
  20. 21. Other Lipids <ul><li>Phospholipids … important in cell membranes </li></ul><ul><li>Steroids … testosterone, cholesterol, hormones </li></ul>
  21. 22. Proteins <ul><li>Contain C, H, O, N, sometimes P and S </li></ul><ul><li>Polymers of amino acids </li></ul><ul><li>Functions: Basis of Protein hormones (eg., insulin, growth hormone), structural components of muscle (actin and myosin), & skin (collagen & keratin), antibodies (immunoglobulins), transport molecules (hemoglobin), cell surface receptors and channels, enzymes, pigments </li></ul>
  22. 23. Proteins <ul><li>Make up skin and muscles. </li></ul><ul><li>Used as catalysts in the form of enzymes. </li></ul><ul><li>Amino acids (monomers) are linked together to form peptides. </li></ul>
  23. 24. Protein Structure
  24. 26. Nucleic Acids (RNA and DNA) <ul><li>Polymers of nucleotides </li></ul><ul><li>A single nucleotide: </li></ul><ul><li>Carry and transmit hereditary information </li></ul><ul><li>Direct the synthesis of proteins </li></ul>Adenine, guanine, thymine, cytosine or uracil (RNA only)
  25. 29. Got all that? <ul><li>Knight Starts Monday. </li></ul><ul><li>Check wall for room assignment. </li></ul><ul><li>Unit 1 test next Friday!!!! Covers EVERYTHING since beginning of year. Review all notes and vocabulary. </li></ul><ul><li>Characteristics of life. </li></ul><ul><li>Scientific Method </li></ul><ul><li>Chemistry. </li></ul><ul><li>Molecules of life. </li></ul>