9-14-09_lecture_proteinIDA

9-14-09_lecture_proteinIDA - Poets say science takes away...

Info icon This preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Poets say science takes away from the beauty of the stars - mere globs of gas atoms. I, too, can see the stars on a desert night, and feel them. But do I see less or more?” - Richard Feynman “Marge: Homer! There's someone here who can help you... Homer: Is it Batman? Marge: No, he's a scientist. Homer: Batman's a scientist?! Marge: It's not Batman!”
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Announcements Answers to the review questions will be passed out today Papers for your research article summary are available in Blackboard. First exam – This Friday, September 18 th
Image of page 2
Noncovalent bonds are critical for the formation of protein secondary and tertiary structures from a given amino acid chain (primary structure)
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Hydrophobicity also plays an important role in determining protein structure Alberts et al. Molecular Biology of the Cell
Image of page 4
All structures are Gibbs free energy minimizers, and proteins are particularly studied in this manner 2200 G= E +p V –T S, where G is the Gibbs free energy, E is the energy (assume constant pressure), V is volume, T is temperature in Kelvin, and S is entropy Given some starting configuration of a structure, want to minimize G (make G as negative as possible) Changes in potential energy result from electrostatic interactions (covalent, hydrogen bonds, van der Waals) “Hydrophobicity results from depriving water molecules of some of their configurational entropy” (from Physical Biology of the Cell)
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Can compute energetic cost function of different protein configurations to determine stable states Computationally very expensive for a realistic sized protein Can have a stable state without having a global free energy minimum Relative minimum (stable) Global minimum (stable) Local minimum (unstable)
Image of page 6
Changes in free energy paths are dynamic due to a changing environment and changing protein conformation In this analogy, we can consider the offense as trying to find a low energy path for the ball to reach the stable state of the endzone, while the defense is trying to find a “low” energy path to reach the stable state of the ground or a change in possession. The point is that, from the ball’s point of view, the free energy paths to stable states are in constant flux due to changes in the conformations of the different components www.directsnapfootball.com
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Second string: One major type of secondary structure is the alpha helix conformation • Discovered by Linus Pauling and Robert Corey and confirmed using X-ray crysallography
Image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern