Shared Flashcard Set

Details

Biochem 3 - Protein Folding
by Chelsea (Complete)
19
Medical
Graduate
11/19/2008

Additional Medical Flashcards

 


 

Cards

Term
What are three types of noncovalent forces that drive protein folding?
Definition
Ionic/electrostatic interactions, hydrogen bonds, hydrophobic interactions
Term
What are two examples of ionic/electrostatic interactions?
Definition
salt bridges and dipoles
Term
What are two noncovalent forces that must be overcome so that a protein can fold?
Definition
enthalpic forces (ie: when unfolded polypeptide wants to bond with the solvent) and entropic forces
Term
How are secondary structures stabilized?
Definition
By hydrogen bonding between peptide amide (N-H) and carbonyl groups (C=O)
Term
How many residues are in a typical helix?
Definition
10-14
Term
What does it mean when you way "Helices are often amphipathic"
Definition
They have distinct hydrophobic and hydrophilic sides
Term
What amino acid breaks alpha helices?
Definition
Proline
Term
What arrangement of the polypeptide chains in a beta-pleated sheet is the most stable?
Definition
anti-parallel (parallel and mixed are less stable)
Term
Where would you find a "turn" in a peptide chain?
Definition
Usually at protein surfaces. They contain hydrophilic residues (ie: proline, glycine)
Term
How could you have charged or hydrophilic residues in a generally hydrophobic protein core?
Definition
They form complementary interactions (like salt bridges)
Term
What is tertiary structure?
Definition
The final arrangement of domains within the folded protein
Term
What are the steps in protein folding?
Definition
primary structure --> "molten globule complex" (exhibit secondary structures of alpha helices and beta sheets) --> tertiary structure --> quaternary structure
Term
What are chaperones called "heat shock proteins?"
Definition
They are induced during stress (eg: heat shock)
Term
What does prolyl cic-trans isomerase do?
Definition
Accelerates the rotation around the peptide bond of proline (which is typically very slow)
Term
How does ubiquitin link to lysine?
Definition
amide bonds with the Ub C-terminus
Term
What enzyme series activates ubiquitin?
Definition
E1, E2, E3s
Term
What enzyme series activates ubiquitin?
Definition
E1, E2, E3s
Term
What happens when a protein is marked by a chain of at least 4 ubiquitin molecules?
Definition
It is degraded by proteasomes
Term
What are 5 examples of amyloid diseases?
Definition
Alzheimer's, Parkinsons, PolyQ, Prion, Systemic amyloidosis
Supporting users have an ad free experience!