Determine the Ka for the biotin-avidin reaction in Question 3.
A. 1015 M
B. 1015 M
C. 1015 M1
D. 1015 M1
E. 108 M
The helix contains ______________ amino acids residues per turn. One full turn of the helix is ______________ long.
A. 5.4, 3.6
B. 36, 54
C. 3.6, 5.4
D. 5.4, 1.5
E. 3.6, 1.5
Avidin binds biotin with a Kd of 1015 mol/L. A protein of interest can be covalently linked to biotin and subsequently isolated by incubating with beads coated with avidin.
If the concentration of biotinylated protein is 10-8 M at the beginning of the assay and the beads provided an excess of avidin-binding sites, then one could expect the beads to bind:
A. a small fraction of the protein in the sample.
B. approximately half the protein in the sample.
C. almost all of the protein in the sample.
D. 1015 mol of protein per 1 mL of sample.
E. This cannot be predicted.
The Kd for a protein-ligand interaction is:
A. the rate at which the protein binds ligand.
B. the square root of the equilibrium constant.
C. the fraction of ligand-binding sites occupied at equilibrium.
D. the ligand concentration at which half of the available ligand-binding sites are occupied.
E. None of these choices is correct.
At pH 11, a peptide with the sequence G-M-G-V-S-D-P-D-A has the net charge of:
A. -3
B. -2
C. -1
D. +1
E. +2