1b; chemistry, molecules


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1b; chemistry, molecules

  1. 1. Lecture 1b <ul><li>Basic Chemistry </li></ul><ul><li>Biological Molecules </li></ul><ul><li>Introduction to Cells </li></ul>
  2. 2. Basic Chemistry <ul><li>Atomic theory </li></ul><ul><li>All matter is made of atoms </li></ul><ul><li>Molecules are atoms bonded together </li></ul><ul><li>Not all atoms can bind; depends on their nature </li></ul><ul><li>Types of bonds </li></ul><ul><ul><li>Ionic - electrons ‘donated’, creating charge </li></ul></ul><ul><ul><li>Covalent - electrons shared </li></ul></ul><ul><ul><li>H bonds </li></ul></ul>
  3. 3. Basic Chemistry <ul><li>Bonds can be strong or weak </li></ul><ul><li>Chemicals form different shapes and the shape influences the activity of the chemical </li></ul><ul><li>Chemical reactions are the basis for most life processes </li></ul>
  4. 4. Chemical bonds <ul><li>Ionic bond </li></ul>
  5. 5. Covalent Bond
  6. 6. WATER <ul><li>Water has polarity </li></ul><ul><li>Leads to H bonds </li></ul>
  7. 7. Water <ul><li>Water is a solvent </li></ul><ul><ul><li>Dissolves ionic substances and other polar nonionic substances </li></ul></ul>
  8. 8. Water <ul><li>Cohesion </li></ul><ul><ul><li>Water clings to itself </li></ul></ul><ul><ul><ul><li>Surface tension </li></ul></ul></ul><ul><li>Adhesion </li></ul><ul><ul><li>Water clings to other stuff too </li></ul></ul><ul><ul><ul><li>How it gets in everywhere </li></ul></ul></ul>
  9. 9. Water <ul><li>High heat capacity </li></ul><ul><ul><li>T of water rises and falls slowly </li></ul></ul><ul><ul><ul><li>How organisms are able to live in a changing environment </li></ul></ul></ul><ul><li>High heat of vaporization </li></ul><ul><ul><li>Has to be really hot to break H bonds and turn to steam </li></ul></ul>
  10. 10. Water <ul><li>Ice is less dense than liquid water </li></ul><ul><ul><li>Allows aquatic organisms to live underneath ice because it is on the surface </li></ul></ul>
  11. 11. Carbon <ul><li>Because C forms 4 bonds, it is very versatile </li></ul><ul><li>C chains are the basis of organic molecules (molecules containing C and H) </li></ul><ul><li>Organic molecules are divided into 4 groups: Carbohydrates, Lipids, Proteins, Nucleic Acids </li></ul><ul><li>Most are made up of polymers of different types of monomers </li></ul>
  12. 12. Carbohydrates <ul><li>Polymers of saccharides (sugars) </li></ul><ul><ul><li>Energy use </li></ul></ul><ul><ul><ul><li>Glucose </li></ul></ul></ul><ul><ul><li>Energy storage </li></ul></ul><ul><ul><ul><li>Starch in plants; glycogen in animals </li></ul></ul></ul><ul><ul><li>Structure </li></ul></ul><ul><ul><ul><li>Cellulose in plants; chitin </li></ul></ul></ul>
  13. 13. Lipids <ul><li>NOT soluble in water </li></ul><ul><ul><li>Fatty acid tails (usually 3) keep from dissolving </li></ul></ul><ul><li>Fats and oils; primary energy storage </li></ul><ul><ul><li>Fatty acid tails come in three varieties: </li></ul></ul><ul><ul><ul><li>Unsaturated, saturated, and trans </li></ul></ul></ul>
  14. 14. Lipids <ul><li>Not all lipids are bad! </li></ul><ul><li>Phospholipids </li></ul><ul><ul><li>Have polar heads (water soluble); but non-polar tails (not soluble) </li></ul></ul><ul><ul><li>This makes them arrange themselves in a bilayer </li></ul></ul><ul><ul><li>These create the membranes of cells </li></ul></ul>
  15. 15. Proteins <ul><li>Important to structure and function of cells </li></ul><ul><ul><li>Support </li></ul></ul><ul><ul><li>Metabolism </li></ul></ul><ul><ul><li>Transport </li></ul></ul><ul><ul><li>Defense </li></ul></ul><ul><ul><li>Regulation </li></ul></ul><ul><ul><li>Motion </li></ul></ul>
  16. 16. Proteins <ul><li>Amino acids are the building blocks of proteins </li></ul><ul><ul><li>There are 20 amino acids- combine in different ways to form thousands of different proteins </li></ul></ul><ul><ul><li>The ‘chain’ of amino acids determines its shape, and therefore its function </li></ul></ul>
  17. 17. Proteins <ul><li>Function of protein is determined by its shape </li></ul><ul><li>There are 4 levels of structure: </li></ul><ul><ul><li>Primary: the sequence of aa </li></ul></ul><ul><ul><li>Secondary: alpha helix, pleated sheet- formed by H bonds between aa </li></ul></ul><ul><ul><li>Tertiary: the globular shape </li></ul></ul><ul><ul><li>Quaternary: more than one </li></ul></ul>
  18. 18. Nucleic Acids <ul><li>DNA and RNA are the nucleic acids in cells </li></ul><ul><li>Nucleotides are the monomers </li></ul><ul><li>DNA stores genetic info </li></ul><ul><li>RNA takes genetic info to site of protein synthesis </li></ul>
  19. 19. DNA <ul><li>Each nucleotide in DNA contains one of 4 different bases: adenine, guanine, cytosine, thymine </li></ul><ul><ul><li>G always bonds to C; A always bonds to T in double helix structure </li></ul></ul><ul><ul><li>Very important to replication </li></ul></ul><ul><li>Every 3 bases stands for one amino acid </li></ul><ul><ul><li>So, if you know sequence of gene, you know sequence of protein </li></ul></ul>
  20. 20. RNA <ul><li>RNA is single stranded </li></ul><ul><li>The complementary pairs allow information to be passed to RNA from DNA; protein synthesis actually occurs from RNA </li></ul>
  21. 21. Nucleic Acids to Proteins <ul><li>Very small changes in a gene can potentially result in very large changes in protein </li></ul><ul><ul><li>Ex. Sickle cell: one aa difference </li></ul></ul>
  22. 22. Cells! <ul><li>Why are cells small? </li></ul><ul><ul><li>Surface to volume ratio- gives adequate surface area for exchange of chemicals </li></ul></ul><ul><li>All cells have an outer plasma membrane , which encloses the cytoplasm </li></ul>
  23. 23. Cells <ul><li>Two main types of cells: prokaryotic and eukaryotic </li></ul><ul><ul><li>Prokaryotes do not have a membrane bound nucleus, eukaryotes do </li></ul></ul><ul><ul><li>Bacteria are prokaryotes </li></ul></ul><ul><ul><li>Extremely successful, widespread and necessary </li></ul></ul>
  24. 24. Prokaryotic structure <ul><li>The membrane is surrounded by cell wall and sometimes capsule </li></ul><ul><li>DNA of bacterium is in a region called the nucleoid </li></ul><ul><li>Ribosomes produce proteins </li></ul><ul><li>Appendages include flagella, fimbriae, and conjugation pilli </li></ul>
  25. 25. Bacteria <ul><li>Fun fact: bacteria can smell! </li></ul>