Organic Macromolecules

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Introduction to organic macromolecules

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Organic Macromolecules

  1. 1. Chapter 5 The Structure and Function of Macromolecules BIO 101 Southwest Virginia Community College Kevin Stilwell Assistant Professor of Biology BIOLOGY 7th edition Neil Campbell, Jane Reece and Chris Romero
  2. 2. <ul><li>Macromolecules “macro” = large </li></ul><ul><ul><li>Are large molecules composed of smaller molecules </li></ul></ul><ul><ul><li>Are complex in their structures </li></ul></ul><ul><ul><li>4 Major categories of macromolecules are Carbohydrates, Lipids, Proteins, Nucleic Acids </li></ul></ul>
  3. 3. <ul><li>For each of the 4 major groups of macromolecules know the </li></ul><ul><ul><li>Elements they are composed of </li></ul></ul><ul><ul><li>Know their chemical structures </li></ul></ul><ul><ul><li>Know specific examples within each group and each subgroup. For example </li></ul></ul><ul><ul><ul><li>Monosaccharides, disaccharides, and polysaccharides </li></ul></ul></ul><ul><ul><ul><li>Phospholipids </li></ul></ul></ul><ul><ul><ul><li>Primary, Secondary, Tertiary and Quaternary structures of proteins </li></ul></ul></ul>
  4. 4. <ul><li>Most macromolecules are polymers, built from monomers </li></ul><ul><li>A polymer </li></ul><ul><ul><li>Is a long molecule consisting of many similar building blocks called monomers </li></ul></ul><ul><li>Three of the classes of life’s organic molecules are polymers </li></ul><ul><ul><li>Carbohydrates- consist of three elements: C, H, and O in a 1:2:1 ratio such as C 6 H 12 O 6 or C 12 H 22 O 11 </li></ul></ul><ul><ul><li>Proteins – consist of the elements C, H, O, N </li></ul></ul><ul><ul><li>Nucleic acids – consist of the elements C, H, O, N, P </li></ul></ul>
  5. 5. The Diversity of Polymers <ul><li>Each class of polymer </li></ul><ul><ul><li>Is formed from a specific set of monomers </li></ul></ul><ul><ul><li>Large carbohydrate polymers are made of monomers called monosaccharides (simple sugars) </li></ul></ul><ul><ul><li>Large polypeptide and protein polymers are made of monomers called amino acids </li></ul></ul><ul><ul><li>Large nucleic acid polymers (DNA and RNA) are made of monomers called nucleotides </li></ul></ul>1 2 3 HO H
  6. 6. <ul><li>Although organisms share the same limited number of monomer types, each organism is unique based on the arrangement of monomers into polymers </li></ul><ul><li>An immense variety of polymers can be built from a small set of monomers. </li></ul><ul><ul><li>Variation is accomplished by rearranging the order of the monomers within the polymer. (scrambling the components that make up a polymer creates a different polymer with different biological and chemical and physical properties) </li></ul></ul>
  7. 7. Carbohydrates <ul><li>Carbohydrates serve as fuel (energy source) for metabolism and serves as a building material </li></ul><ul><li>Carbohydrates - Include sugars and their polymers </li></ul><ul><li>Monosaccharides – Are Simple Sugars , such as glucose, fructose and galactose </li></ul><ul><ul><ul><li>Are the simplest sugars (have about 3 to 7 carbon atoms in their chemical structure) </li></ul></ul></ul><ul><ul><ul><li>Can be used for fuel (energy) Glucose is the most important energy source for cells </li></ul></ul></ul><ul><ul><ul><li>Can be converted into other organic molecules </li></ul></ul></ul><ul><ul><ul><li>Can be combined into polymers </li></ul></ul></ul>
  8. 8. Polysaccharides <ul><li>Polysaccharides or Complex Carbohydrates </li></ul><ul><ul><li>Are polymers of sugars </li></ul></ul><ul><ul><li>Serve many roles in organisms </li></ul></ul><ul><ul><li>Examples of polysaccharides are: </li></ul></ul><ul><ul><ul><li>Starch </li></ul></ul></ul><ul><ul><ul><li>Cellulose </li></ul></ul></ul><ul><ul><ul><li>Glycogen </li></ul></ul></ul><ul><ul><ul><li>Chitin (pronounced “Kite – in” ) </li></ul></ul></ul>
  9. 9. <ul><li>Lipids are a diverse group of hydrophobic molecules consisting of the elements C, H, and O, ( not a 1:2:1 ratio) because there is less oxygen in Lipids than in carbohydrates </li></ul><ul><li>Lipids </li></ul><ul><ul><li>Are the one class of large biological molecules that do not consist of polymers </li></ul></ul><ul><ul><li>All types of lipids share the common trait of being hydrophobic </li></ul></ul><ul><ul><li>Insoluble in water – They do not dissolve in water due to their nonpolar, hydrophobic properties </li></ul></ul><ul><ul><li>Contain twice as much energy per gram as carbohydrates or proteins </li></ul></ul>
  10. 10. Phospholipids p 76 <ul><li>Phospholipids </li></ul><ul><ul><li>Have only two fatty acids </li></ul></ul><ul><ul><li>Have a phosphate group instead of a third fatty acid </li></ul></ul><ul><ul><li>Make up an important component of the plasma membrane (called the phospholipid bilayer) of cells </li></ul></ul>
  11. 11. Enzymes, Polypeptides, and Proteins <ul><li>Enzymes p 78 </li></ul><ul><ul><li>Are a type of protein that function as catalysts, speeding up chemical reactions </li></ul></ul><ul><li>Polypeptides </li></ul><ul><ul><li>Are polymers of amino acids (containing fewer than 100 amino acids) </li></ul></ul><ul><li>Proteins </li></ul><ul><ul><li>Consist of one or more polypeptides </li></ul></ul><ul><ul><li>Are large polymers of amino acids with more than 100 amino acids, usually several hundred to over 1000 amino acids linked together by peptide bonds </li></ul></ul>
  12. 12. Amino Acid Monomers <ul><ul><li>Are organic molecules possessing both carboxyl (COOH) and amino groups (NH 2 ) </li></ul></ul><ul><ul><li>Differ in their properties due to differing side chains, called R groups (the R part of an amino acid may consist of a single element or a much larger group of elements) </li></ul></ul><ul><ul><li>The carboxyl group and amino group are always found on opposite ends of an amino acid </li></ul></ul><ul><ul><li> R </li></ul></ul><ul><ul><li>HOOC C NH 2 </li></ul></ul><ul><ul><li> H </li></ul></ul><ul><li>20 different amino acids make up proteins p. 79 </li></ul><ul><ul><li>Each shares a similar structure, but each varies in the R group which gives each amino acid its own characteristic physical and chemical properties </li></ul></ul>
  13. 13. Determining the Amino Acid Sequence of a Polypeptide <ul><li>Amino Acid sequences within a cell are determined by the cell’s genetic information (DNA) </li></ul><ul><li>In the laboratory, the amino acid sequences of polypeptides </li></ul><ul><ul><li>Were first determined using chemical means </li></ul></ul><ul><ul><li>Can now be determined by automated machines </li></ul></ul>
  14. 14. <ul><li>Nucleic acids store and transmit hereditary information </li></ul><ul><li>Genes – segments of DNA on a chromosome </li></ul><ul><ul><li>Are the units of inheritance </li></ul></ul><ul><ul><li>Contain the program (or genetic code) that sets the amino acid sequence of polypeptides </li></ul></ul><ul><ul><li>Are made of nucleic acids and are located on chromosomes </li></ul></ul>
  15. 15. The Roles of Nucleic Acids <ul><li>There are two types of nucleic acids </li></ul><ul><ul><li>Deoxyribonucleic acid ( DNA ) </li></ul></ul><ul><ul><li>Ribonucleic acid ( RNA ) </li></ul></ul>
  16. 16. RNA <ul><li>Is synthesized in the nucleus </li></ul><ul><li>Is single stranded and contains the pentose sugar called ribose </li></ul><ul><li>Plays an important role in the synthesis of proteins </li></ul><ul><ul><li>By transporting the genetic information encoded in DNA to other parts of a cell where the protein is actually synthesized </li></ul></ul><ul><li>DNA transcription RNA translation Protein </li></ul>
  17. 17. DNA <ul><li>Stores information for the synthesis of specific proteins </li></ul><ul><li>Directs RNA synthesis </li></ul><ul><li>Contains the instructions for protein synthesis through RNA </li></ul><ul><li>The double helix structure of DNA is illustrated to the right  </li></ul><ul><li>Source: http://creativecommons.org/ search engine; file from Flickr.com Uploaded on June 12, 2007 by ynse file retrieved June 19, 2009. </li></ul>
  18. 18. The DNA Double Helix <ul><li>Cellular DNA molecules </li></ul><ul><ul><li>Have two polynucleotides that spiral around an imaginary axis </li></ul></ul><ul><ul><ul><li>Often referred to as being “double stranded” </li></ul></ul></ul><ul><ul><li>DNA exhibits a structure called a double helix </li></ul></ul><ul><ul><ul><li>The double helix structure of DNA is often compared to a spiral staircase </li></ul></ul></ul>

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