Bioc 2580 Midterm UPDATED Exam
Questions and CORRECT Answers
Partition Chromatography - CORRECT ANSWER - Separation
Stationary phase: solid (silica gel) can H-bond polar AA
Mobile phase: solvent flows past particles
Polar move slower, non-polar move faster
Polarity
Thin Layer Chromatography - CORRECT ANSWER - Silica gel in thin layer
Lower edge has samples, placed in solvent, travels up
Very polar = low Rf, non-polar = high Rf
Polarity
Column Chromatography - CORRECT ANSWER - Sample mix added to column
Buffer added, elution volume characteristic of compound
Ion Exchange Chromatography - CORRECT ANSWER - Charged stationary phase
Cation exchanger = bind cations
Anion exchanger = bind anions
Elution by competition or pH change, each AA has unique elution volume
Greater charge = more tightly bonded
Polarity
Metal Affinity Chromatography - CORRECT ANSWER - His-tag added to protein gene
His binds tightly to Ni2+, resin has Ni2+
Elution by flooding with imidazole
, Gel Filtration or Molecular Exclusion - CORRECT ANSWER - Beads with different sized
pores
Proteins can enter pores if they fit
Large proteins excluded, travel faster than smaller that can enter
Size
Ultracentrifugation - CORRECT ANSWER - Forces cause molecules to sediment at rate
dependent on size and shape
Can determine apparent molecular mass
Size and Shape
Electrophoresis - CORRECT ANSWER - Separation based on movement of charged
molecules in electric field
Done in gel (polyacrylamide gel)
Size, shape, charge
SDS-PAGE - CORRECT ANSWER - SDS-polyacrylamide gel electrophoresis
Protein treated with SDS unfolding it and giving it uniform negative charge
Small proteins fit in pores and move faster than large that take more time to move through gel
Size
Isoelectric Focusing - CORRECT ANSWER - Isoelectric point - pH where net charge = 0
Gradient of decreasing pH where protein starts at negative electrode and moves toward positive
until net charge = 0
Each protein has different isoelectric point
Charge
Two Dimensional Gel - CORRECT ANSWER - Complex samples
Isoelectric focusing and SDS electrophoresis
Questions and CORRECT Answers
Partition Chromatography - CORRECT ANSWER - Separation
Stationary phase: solid (silica gel) can H-bond polar AA
Mobile phase: solvent flows past particles
Polar move slower, non-polar move faster
Polarity
Thin Layer Chromatography - CORRECT ANSWER - Silica gel in thin layer
Lower edge has samples, placed in solvent, travels up
Very polar = low Rf, non-polar = high Rf
Polarity
Column Chromatography - CORRECT ANSWER - Sample mix added to column
Buffer added, elution volume characteristic of compound
Ion Exchange Chromatography - CORRECT ANSWER - Charged stationary phase
Cation exchanger = bind cations
Anion exchanger = bind anions
Elution by competition or pH change, each AA has unique elution volume
Greater charge = more tightly bonded
Polarity
Metal Affinity Chromatography - CORRECT ANSWER - His-tag added to protein gene
His binds tightly to Ni2+, resin has Ni2+
Elution by flooding with imidazole
, Gel Filtration or Molecular Exclusion - CORRECT ANSWER - Beads with different sized
pores
Proteins can enter pores if they fit
Large proteins excluded, travel faster than smaller that can enter
Size
Ultracentrifugation - CORRECT ANSWER - Forces cause molecules to sediment at rate
dependent on size and shape
Can determine apparent molecular mass
Size and Shape
Electrophoresis - CORRECT ANSWER - Separation based on movement of charged
molecules in electric field
Done in gel (polyacrylamide gel)
Size, shape, charge
SDS-PAGE - CORRECT ANSWER - SDS-polyacrylamide gel electrophoresis
Protein treated with SDS unfolding it and giving it uniform negative charge
Small proteins fit in pores and move faster than large that take more time to move through gel
Size
Isoelectric Focusing - CORRECT ANSWER - Isoelectric point - pH where net charge = 0
Gradient of decreasing pH where protein starts at negative electrode and moves toward positive
until net charge = 0
Each protein has different isoelectric point
Charge
Two Dimensional Gel - CORRECT ANSWER - Complex samples
Isoelectric focusing and SDS electrophoresis
