week 2: noncovalent interactions, protein structure, and protein purification

Question 1

how is water oriented around np solutes

Answer 1

highly ordered cages

Question 2

what drives macromolecular structure formation

Answer 2

entropy

Question 3

what stabilizes macromolecular structure formations

Answer 3

enthalpy – noncovalent interaction

Question 4

what drives protein folding of hydrophobic regions in H2O

Answer 4

aggregations of hydrophobic portions frees water from ordered water cages (entropy increases)

Question 5

number of possible structures based on # of residues

Answer 5

20^n structures, n = # residues

Question 6

what is primary structure

Answer 6

sequence of amino acids

Question 7

what does primary structure determine?

Answer 7

sequence determines structure

Question 8

what is secondary structure

Answer 8

folding of backbone

Question 9

constraints to secondary structure

Answer 9

no rotation around peptide bond; limited rotation of R groups due to sterics and electrostatic repulsion (charged group); proline

Question 10

characteristics of regular secondary structure

Answer 10

allowable backbone config, maximizes side chain interactions, satisfies all H bonds available

Question 11

where are H bonds in proteins

Answer 11

peptide bonds:

carbonyl is H bond acceptor and amide is H bond donor

Question 12

where does tertiary and quaternary structure come from

Answer 12

interactions between amino acid side chains

Question 13

what types of bonds contribute to delta H

Answer 13

molecular bonds, IMF

Question 14

what role does enthalpy play in macromolecular structure formation

Answer 14

not much, most interactions can be satisfied in folded or unfolded state