These three amino acids go by the abbreviations of Phe, Cys, and Val.
What are Phenylalanine (Phe, F), Cysteine (Cys, C), and Valine (Val, V)?
100
If you know Ka, this is how you can find pKa.
What is -logKa?
100
This type of bond forms between two cysteine residues, and has a stabilizing effect on proteins.
What is a Disulfide Bond?
100
This protease cleaves peptide bonds at F, Y, and W.
What is Chymotrypsin?
100
This constant is a measure of the strength of an acid in a solution.
What is Ka: Acid Dissociation Constant?
200
These amino acids are classified as acidic at neutral pH.
What are Aspartic Acid (Asp, D), and Glutamic Acid (Glu,E)?
200
This is the Henderson-Hasselbach Equation.
What is pH=pKa + log[A-]/[HA]?
200
Predict the charge on the predominant species of the peptide E-D-K-R-A-S-T at pH 5.0.
What is 0?
200
This is the equation to find specific activity of a protein.
What is [uM product formed]/[min/mg protein]?
200
This principle states that a system will react to maintain equilibrium.
What is Le Chatlier's Principle?
300
These amino acids are classified as basic at neutral pH.
What are Lysine (Lys,K), Arginine (Arg, R), and Histidine (His, H)?
300
A buffer solution is made using a weak acid, HA, with a pKa of 5. If the ratio of A– to HA is 0.001, what is the pH of the buffer?
What is 2?
Solution:
pH=pKa + log [A-/HA]
pH=5 + log [.001]
pH=2
300
These amino acids present in a protein can absorb UV light.
What are Phenylalanine, Tyrosine, and Tryptophan?
300
This compound cleaves peptide bonds after MET, and changes MET to homoserine lactone.
What is CNBr (Cyanogen Bromide)?
300
This is the pH value at which the sum of the positive and negative electrical charges in a protein is 0.
What is Isoelectric Point?
400
These amino acids have a pKa of about 13.
What are Threonine (Thr, T), and Serine (Ser, S)?
400
What is the ratio of [A–]/[HA] at pH 5.75? The pKa of formic acid (H–COOH) is 3.75.
What is 100?
Solution:
pH=pKa + log [A-/HA]
Solving for the ratio of [A–]/[HA] we get:
[A–]/[HA] = 10^[pH-pKa]
[A–]/[HA] = 10^[5.75-3.75]
[A–]/[HA] = 100
400
These are 4 common types of posttranslational modifications that newly synthesized proteins can undergo.
What are phosphorylation, proteolysis, carboxylation, addition of hydrophobic groups?
400
In this purification technique, compounds with a lower molecular weight travel a longer distance in the gel.
What is SDS-Page?
400
This is the point when the concentration of [A-]=[HA] and is the best buffer zone in a titration.
What is the equivalence point? (Also known as the 50:50 point)
500
These two amino acids have a pKa of approximately 10.5.
What are Lysine (Lys, K) and Tyrosine (Tyr, Y)?
500
If you want to make 1000mL of CAPS buffer in the lab, this is the value (in mols) of NaOH that is necessary to bring the pH up to 11.0.
(pKa CAPS = 10.4)
What is .008 mol?
Solution:
pH=pKa + log [A-/HA]
11.0=10.4 + log[A-/HA]
0.6=log[A-/HA]
10^0.6=[A-/HA]
3.98HA=A, A+HA=.01M
3.98HA + 1HA = .01M
4.98HA=.01M
[HA]= .002M
[A-]=.008M
The molarity of [A-] is the molarity of NaOH that must be added.
.008M/1 L = .008 mol per 1000 mL
500
This sequencing method can give us information to homology of proteins by detecting local as well as global alignments where protein sequences are in close agreement.
What is BLAST (Basic Local Alignment Search Tool)?
500
This compound is a cation exchanger (1) and is used in this technique (2).
(two answers)
What is (1) Cellulose phosphate, and (2) Ion Exchange Chromatography
500
This is the term to describe an amino acids that carries 2 charges at a certain pH which gives the amino acid ionic properties.