Lecture 2 Flashcards
What is the distinction between amide and peptide bonds?
Not every amide bone is a peptide bond but every peptide bond is an amide bond. A peptide bond is an amide bond that is specifically used in the formation of polypeptides. Basically a peptide bond is a type of amide bond
Why is water so important?
Because it is the environment in which we find every biological molecule
Where does water’s special properties come from?
The difference in electronegativity between oxygen and hydrogen atoms
What is the shape of water molecules?
It has a tetrahedral position
How many lone pairs does a water molecule have?
2 pairs of lone pairs
What does the net dipole of water molecules allow?
It allows water to form hydrogen bonds with other water molecules
What is Hydrogen Bonding?
When one hydrogen is being shared by two electronegative atoms
What is the Hydrogen in the hydrogen bond donor attracted to?
The lone pair of the oxygen on the water molecule
What is the relative strength between hydrogen bonds and covalent bonds?
Hydrogen bonds are weaker than covalent bonds
How many hydrogen bond interactions can be formed per water molecule?
There are four: Two as a donor and two as an acceptor
What is the relative length for hydrogen bond vs covalent bonds?
Hydrogen bond interactions are over a greater length than covalent bonds
What must a hydrogen bond acceptor have?
A lone pair that must be in a hybridized orbital
Why does ice form a lattice?
Because of the regular orientation of hydrogen bonding
What are the hydrogen bonds like in water form?
Hydrogen bonds are constantly reforming and braking
How many hydrogen bonds per a water molecule are usually forming?
Usually 2-3 hydrogen bonds but can form up to four
What is energy like when releasing and forming hydrogen bonds?
There is an input of energy required to break hydrogen bonds and a release of energy when forming hydrogen bonds
how many hydrogen bonds can a hydronium ion form?
Four: Three as a donor and one as an acceptor
What are the two non-covalent biological interactions of importance?
- Electrostatic forces
* Hydrophobic effects
What are the three types of electrostatic forces?
- Ionic interactions
- Hydrogen bonds
- Van der Waals
What are the two types of Van Der Waals forces?
- Dipole-Dipole interactions
* London dispersion forces
What are Van der Waals interactions?
Interactions between permanent dipoles or induced dipoles
What are Hydrophobic effects?
Interactions that favor bringing non polar groups together that have a preference for not interacting water
What do Dipole Dipole interactions occur between?
Polar non-charged groups
What do London dispersion forces occur between?
Nonpolar molecules that have an induced dipole
