Chapter 1: 1.1 Bonds in Biochemistry Flashcards
Describe:
Hydrogen Bonds
Requires an H-bond donor (hydrogen bound to an electronegative atom - O, N, or S) and an H-bond acceptor (an electronegative atom - O, N, or S)
What are hydrogen bonds also known as?
Permanent dipole - Permanent dipole (PD-PD) bonds
What do hydrogen bonds do in an organism?
Plays an important role in protein structure
* Amino acid backbone, cysteine, methionine etc.
List:
Basic bonds in biochemistry (5)
- Hydrogen bonds
- Hydrophobic interactions
- Electrostatic/Ionic interactions
- Van der Waals Forces
- Disulfied bond
Describe:
Hydrophobic interactions
- Hydrophobic: Non-polar. Will repel polar solvents and functional groups
- Hydrophilic: Polar/charged. Will interact with and attract polar solvents and functional groups
How are hydrophobic amino acids arranged?
Arranged in the interior of proteins where they do not interact with the external aqueous environment
How are hydrophilic amino acids arranged?
Arranged on the external surface of proteins where they interact with the external aqueous environment
In hydrophobic interactions:
How do ambivalent amino acids behave?
Equally happy in a hydrophobic environment and a hydrophilic enviroment
In hydrophobic interactions:
Why are ambivalent amino acids happy in either environment?
Water binds strongly to itself
List:
The 20 amino acids in decreasing hydrophobicity
- Isoleucine
- Phenylalanine
- Valine
- Leucine
- Tryptophan
- Methionine
- Alanine
- Glycine
- Cysteine
- Tyrosine
- Proline
- Threonine
- Serine
- Histidine
- Glutamic acid
- Asparagine
- Glutamine
- Aspartic acid
- Lysine
- Arginine
Describe:
Electrostatic/Ionic interactions
Bonds formed between opositely charged molecules
* Electrons are completely transferred over from one valence shell to another
True or False:
The strongest type of covalent bonds is electrostatic/ionic interactions
False, electrostatic/ionic interactions are the strongest type of NON-covalent bonds
In proteins, where do electrostatic/ionic interactions occur? Give an example
Occurs between charged side chains
* E.x. Arginine (+ve) —- Aspartic Acid (-ve)
What are Van der Waals Forces also known as?
Induced-Dipole - Induced-Dipole (ID - ID) bonds
True or False:
Van der Waals Forces are strong
Conditional. They are weak on their own and require tight packing, but are quite strong when many are present in one area
