Proteins Back Page Flashcards
1
Q
Protein Conformations
A
- Different levels of protein structure
2
Q
Levels of protein Structures
A
1° Primary
2° Secondary
3° Tertiary
4° Quaternary
3
Q
1° (Primary) Description
A
- Rarely have a function
- A chain of more than 50 amino acids linked by peptide linkages
- Sequence and type of amino acids present varies
4
Q
1° (Primary) Chemical Bonding Involved
A
- Peptide linkage between the NH2 of one amino acid and the carboxylic acid group of the next amino acid
- No R-group interactions
5
Q
2° (Secondary) Description
A
- one or more polypeptide chains individually coiled into an alpha helix or a beta-pleated sheet
- Ex. Some parts of hemoglobin
6
Q
Beta-Pleaded Sheet Example
A
Spider Webs
7
Q
Alpha Helix Example
A
Keratin
8
Q
2° (Secondary) Chemical Bonding Involved
A
- Hydrogen bonding and a peptide link between the carbonyl and nitrogen of amino acids that are 5 amino acids apart
9
Q
3° (Tertiary) Description
A
- The folding of a coiled (helical or pleated sheet) polypeptide chain
- curl on curl
- Ex. Hemoglobin
10
Q
3° (Tertiary) Chemical Bonding Involved
A
- Hydrophilic and hydrophobic R-groups
- Hydrogen bonding between distant amino acids
- Disulfide bridges
- Prosthetic groups
11
Q
Prosthetic Groups
A
- Inorganic attachments
- Ex. Heme
12
Q
4° (Quaternary) Description
A
- The assembly of 2 or more folded helical sub-units
- Ie. 2 or more different peptide molecules
- Ex. Hemoglobin
13
Q
4° (Quaternary) Chemical Bonding Involved
A
- Hydrophobic interactions (centre of molecule)
- Hydrogen bonding
- R-group interactions (more complicated)
- Van Der Waals forces (intermolecular forces)
14
Q
Why are there Van Der Waals forces in quaternary proteins?
A
Since there’s 2 or more polypeptides
15
Q
Protein Denaturing
A
- The unraveling of a protein which could ultimately alter the proteins function
- Does not necessarily affect peptide bonds
