Chapter 10 Quiz
Tryptophan residues in lectins interact with carbohydrates
Order the following compounds from fastest-slowest and transport rate across the lipid membrane:
Urea, Butyramide, Acetamide
Butyramide, Acetimide, Urea
Describe lyase
forms double bonds by removing groups
Name the 6 types of enzymes
oxidoreductase
transferases
hydrolases
lyases
isomerases
ligases
Serine protease specificities from trypsin, chymotrypsin, Elastaes
Trypsin (arg, lys)
Chymotrypsin (Phe, Trp, Tyr)
Elastase (Ser, Val)
Which has a lower melting point cis, trans conformation
cis
Describe carrier proteins
they transport substances down a concentration gradient and are selective towards what they transport
What would a 100 fold rate enhancement require if delt G double dagger is 5.7 kj/mol
11.4 kJ/mol
Describe oxidoreductases
REDOX reactions
What is the catalytic triad?
Ser, His, Asp
located in the active site help with orientation of the serine protease mechanism
BPG and oxygen transport at high altitudes.
When in higher altitudes, BPG synthesis increases shift O2 curves for high affinity.
Better oxygen absorption and transport
What is true of primary and secondary active transporters
require free energy input to move a substance against it's concentration gradient
Describe catalytic mechanisms of enzymes
always require specific positioning of substrates and catalytic groups
What do some reactions rely on?
Specify types
cofactors
Metal ions and coenzymes (cosubstrates & Prosthetic groups)
What is the michaelous-menson equation
V0=Vmax[S]/ Km+[S]
True or false:
HbS has a lower affinity for oxygen than normal adult HbA
False, HbA and HbS have the same affinity however HbS has a mutation that changes a val-glu which causes aggregation of insoluble filaments in a deoxy state.
Describe secondary active antiport
Moves one substance down gradient and another up gradient
Which amino acid is most likely to act as a covalent catalyst in an enzyme active site
Serine
what do enzymes do?
help to lower the free energy of the reaction
Make the reaction more efficient
What is Km and Ks
Km= binding constant
Ks= dissociation constant
Mutated HbKansasa is unable to form the bond that stabilizes the R state. Compare HbA to HbK
Higher p50 lower affinity for O2
Protein transports Ca2+ ions up a concentration gradient from cytoplasm to ER. What type of transport protein is this?
Primary active uniport
Explain the frequent appearance of His in side chains
His can act as an acid or base under physiological conditions
How do enzymes increase the rates of reactions?
stabilize transition state
proximity and orientation effects
What is the equation for Km?
Km= K-1 + k2/k1