BCH210 EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
structure of glucose transporter - Answer-many trans helices, packed into bundles, 12
segments all together
- 2 conformational states; inward facing and outward facing
insulin receptor structure - Answer-2 subunits made up of alpha and beta chains joined
by disulfide bonds
what stabilizes ribonuclease? - Answer-disulfide bonds
urea - Answer-disrupts non covalent bonds
b-mercaptoethanol - Answer-breaks disulfide bonds
4 approaches to genetic engineering - Answer-clone the gene of interest, insert gene
into a replication vector, insert the plasmid into a bacterial host, grow the bacteria
4 components of plasmids - Answer--origin of replication, selectable marker, multiple
cloning sites, promoter
endonucleases - Answer-cleave DNA at palindromic sites
polymerases - Answer-extend DNA chains by forming phosphoester bonds
ligases - Answer-join two phosphoester bonds together
SDS - Answer-denaturing detegent, dissolves membranes and solubilizes proteins
polyacrylamide gel - Answer-gel matrix to separate proteins
3 amino acids involved in serine protease active site - Answer-ser, his, asp
steps of subtilisin catalytic triad - Answer-1) transition state is stabilized, peptide bond
cleavage occur, substrate covalently binds to enzymes Ser221, second transition state
occurs, enzyme active site is recovered
protease - Answer-enzymes that catalyze breaking of peptide bonds
subtilisin - Answer-protease that initiates nucleophilic attack on peptide bonds through a
serine residue at an active site
, when they tried to engineer disulphide bonds into subtilisin; what aa switch did they
make? - Answer-Serine to Cysteine
how many consecutive helical aa before its classified as Alpha Helix - Answer-4
how many consecutive b sheet aa before its called a Beta Sheet - Answer-min 3
how many consecutive position of b-turns before its called b-turn - Answer-4
top alpha helix forming residues - Answer-Glu, Met, ala, leu, lys
poor alpha helix residues - Answer-gly, pro
top beta sheet forming residues - Answer-val, ile, tyr
poor beta sheet forming aa - Answer-glu, asp, pro
top b-turn - Answer-asn, pro, gly, asp, ser
poor b-turn aa - Answer-ile, val, leu, phe, met
best beta turn - Answer-asn-pro-gly-gly
fusion protein - Answer-found in expression vectors, aid in solubilization of expressed
protein
components of fusion protein - Answer-thioredoxin, his tag, wb tag, desired protein
glucagon structure - Answer-n terminal is beta strand, c terminal is alpha helix
glucagon at high concentration forms what structure (likely what location) - Answer-beta
sheet (pancreas)
glucagon at low concentration forms what structure (likely what location) - Answer-alpha
helix (blood)
what form is glucagon when bound to receptor - Answer-alpha helix
types of protein chromatography - Answer-gel filtration, ion exchange, hplc, affinity
chromatography
gel filtration - Answer-separates proteins based on size
ion exchange - Answer-separates proteins based on net charge
hplc - Answer-separates proteins based on hydrophobicity
