Chapter 9.1 (E1) Flashcards
Intermolecular forces and rotatable bonds.
Intermolecular interactions between two non-polar molecules that induce temporary dipoles due to proximity.
What are London dispersion forces?
Molecules without a permanent dipole moment are considered…
Nonpolar
What is the purpose of the hydrophobic effect?
To keep an otherwise non-polar drug soluble in the blood until it can bind to its intended target or cross a membrane
The intermolecular force caused by the interaction of 2 polar molecules.
What is a dipole-dipole force?
The intermolecular force caused by the interaction of 1 polar and 1 non-polar molecule.
What is a dipole-induced dipole?
A dipole-dipole interaction caused by the interaction between an H-bond donor and an H-bond acceptor.
What is hydrogen bonding?
Give 2 examples of an H-bond donor.
OH and NH groups
Give 2 examples of strong H-bond acceptors and 2 examples of weaker ones.
Strong - O or N w/ lone pair
Weaker - F or Cl
Chemical bonds with an electronegative difference less than or equal to 0.4.
What is pure covalent?
Chemical bonds with electronegative differences greater than 0.4 but less than or equal to 1.8.
What is polar covalent?
Chemical bonds with an electronegative difference greater than 1.8.
What is ionic?
Interaction between two oppositely charged ions.
What is ion-ion?
Interaction between an ion and a polar molecule.
What is ion-dipole?
Interaction between an ion and a non-polar molecule.
What is ion-induced dipole?
The relative acidity of a compound.
What is pKa?
What is the relationship between pKa and acid strength?
Lower pKa = stronger acid
Ionic forces can occur between the drug and the target within a target’s active site. What 2 things in an active site can a drug form an ionic interaction with?
1) Side chain of a charged amino acid
2) Metal cation
True or false: Ionic forces are pKa and pH-dependent.
True
This formula is used to determine the ratio of a molecule as it exists in its conjugate base and acid forms.
What is Henderson-Hasselbach?
What happens when a molecule has too many rotatable bonds? Why?
It will be too flexible, leading to non-specific target binding
What happens when a molecule has too few rotatable bonds? Why?
It will be too rigid and won’t be able to get into the preferred bioactive confirmation
What are 2 ways to reduce the number of rotatable bonds in a compound?
Rings & multi-bonds
The minimum portion of a molecule required for biological activity.
What is a pharmacophore?
