1. Avogadro-Scale Molecular Self-Assembly in Biological Systems Avogadro-Scale Engineering: Form and Function November 18, 19 2003 The Bartos Theater Building E15, MIT Shuguang Zhang Center for Biomedical Engineering, Center for Bits & Atoms Massachusetts Institute of Technology Cambridge, MA 02139, USA

2. Interior of a cell: billions of biomolecules form structures & allow cells to function with little errors.

3. A walking Avogadro being Each adult human is made of ~100 trillion cells (10 14 cells)! Guyton, A.C. & Hall, J.E. (2000) Text Book of Medical Physiology 10th ed. W.B. Saunders. http://www.nobel.se/medicine/laureates/1999/press.html

4. Water Molecules Per Person If each person weighs ~70 kilograms, or 70,000 grams, ~ 70% of that is water, i.e. 70,000 grams x 70% = 49,000 grams of water. Each molecule of water has a molecular weight of 18 daltons (oxygen = 16) + (2 hydrogens). Therefore: 18 grams = 1 mole (6.023x10 23 water molecules = the Avogadro number) And… 49,000 grams divided by 18 gram/mole = 2,722 moles, or 2,722 x 6.023x10 23 water molecules per person! A molecule of water.

5. Numbers of Nucleotides in DNA per Person Each cell in a person contains 2 copies of the genome (3.164x10 9 bases)-- one from the mother and one from the father: 2 x 3.1647x10 9 bases/cell, or ~6.33x10 9 bases/cell. Each adult person is made of ~10 14 cells, or 6.33x10 9 bases/cell x 10 14 cells/person = 6.33x10 23 bases/person!

6. Numbers of Protein in Cells per Person http://www.nobel.se/medicine/laureates/1999/press.html Each cell contains ~ 1 billion (10 9 ) proteins. Each adult is made of 10 14 cells, or 10 9 proteins/cell x 10 14 cells/person = 10 23 proteins/person! The hemoglobin molecule has 4 polypeptide chains -- 2  and 2 .

7. Number of Lipid per Cell per Person Each cell plasma membrane is made of ~200 million lipids. However, each cell also has a nuclear membrane, mitochondrial membranes, Golgi apparati, endo- plasmic reticulum, etc. Collectively, the number of lipids is ~10 9 per cell. Each person is made of ~10 14 cells, or 10 9 lipids/cell x 10 14 cells/person = ~10 23 lipids/person! Myelin surrounds spinal cord nerve fibers.

8. The Ribosome

9. Steve Santoso Yang, Biology/CBA Ph.D. Student

10. Monomeric Surfactant Peptides: A6D, V6D, V6D2, L6D, KL6, KV6 Sylvain Vauthey & Steve Santoso (CBE)

11. V 6 D Peptide Nanotubes 100 nm V6DV6D

12. Sylvain Vauthey PNAS, 4/2002, Steve Santoso, NanoLetters, 7/2002 Geoffrey von Maltzahn Langmuir, 5/2003

13. Peptide Nanotubes are made up of trillions of peptides Vauthey, et al., PNAS, April 16, 2002 Billions of molecules self-assemble into ordered structures

14. What do they have in common? Made by HumanMade by Nature MachinesMolecular machines TransportationHemoglobin Assembly linesRibosomes Digital databaseNucleosomes Copy machinesPolymerases Bulldozer/DestroyerProteases/proteosome Chain couplersLigases Train control centerCentrosome Train tracksActin filament network Mail sorting machineProtein sorting Electric Fences Membranes Gates/keys & passesIon channels Internet/wwwNeuron synapse