{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

LS3-3-10 - Lecture 3 Weak strong Interactions between atoms...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 3 Weak (& strong) Interactions between atoms DNA Structure DNA helical stability Allison: p 22-28
Image of page 1

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

View Full Document Right Arrow Icon
Chemical bonds Two atoms interact by sharing electrons -- holds atoms within a molecule together ( intra-molecular bonding) -- Single bond: two atoms sharing 1 pair of electrons, free rotate -- Double bonds: two atoms sharing 2 pairs of electrons, can not rotate -- Bond strength is ~110 kcal/mol = the energy needed to break the bond STRONG - Covalent bonds
Image of page 2
Polar and non-polar molecules -the structure of a water molecule Polar molecules Water H 2 O Nonpolar molecules Oxygen O 2 Methane CH 4
Image of page 3

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

View Full Document Right Arrow Icon
- Attractive force between positively and negatively charged atoms - In ionic bonds, atoms gain or lose electrons completely to its partner - Strongest noncovalent bond (7 kcal/mol) Four WEAK (noncovalent) Interactions Ionic, Hydrogen bonds, Hydrophobic interactions, And Van der Waals Forces (1-7 kcal/mol) (1) Ionic Interactions
Image of page 4
- H bond is the electrical attraction between a hydrogen atom of one molecule and highly electronegative atom in another molecule. -form when a hydrogen atom is “sandwiched” between two electron- attracting atoms such as O and N. e.g. O-H O O-H N N-H O N-H N Hydrogen bond (2) Hydrogen bonds 3.4Å 2.7Å 3.1Å Involves polar molecules ~3 kcal/mol
Image of page 5

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

View Full Document Right Arrow Icon
- H bonds are particularly important for the high-order structures of polymers, e.g.
Image of page 6
Image of page 7
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