W2L2: Tools to Study Proteins

Question 1

Ion-Exchange Chromatography

Answer 1

separates proteins by charge; charged beads hold back positive or negative ions in the column, then release them

Question 2

Gel Filtration Chromatography

Answer 2

separates proteins by size; smaller proteins can enter pores in beads so they flow more slowly; larger proteins flow through the columns faster

Question 3

Affinity Chromatography

Answer 3

separates proteins based on specific interactions; ex. antibodies bind a specific protein

Question 4

Epitope

Answer 4

the unique region on the antigen that is recognized by the antibody; can be used for protein tagging so antibodies can tag it to purify the protein

Question 5

Immunoblotting (Western Blotting)

Answer 5

identifies the presence of certain proteins in a sample; after electrophoresis, transfer to membrane, wash with first and secondary antibody, and visualize with autoradiogram

Question 6

Immunoprecipitation

Answer 6

isolate specific proteins and binding partners

Question 7

Immunofluorescence

Answer 7

localize specific proteins in within cells

Question 8

SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis)

Answer 8

protein samples are separated by size using charge through a gel

Question 9

Sodium Dodecyl Sulfate (SDS)

Answer 9

strong ionic detergent; denatures proteins and coats proteins with a uniform negative charge

Question 10

Beta-Mercaptoethanol (BME)

Answer 10

reducing agent that removes disulfide bond; applied before protein gel electrophoresis

Question 11

Secondary Antibody

Answer 11

Western blotting, amplifies signal output and is radioactively tagged

Question 12

Autoradiogram

Answer 12

image produced by the pattern of decay emissions (ex. beta particles or gamma rays) from a radioactive antibody

Question 13

Fluorescence

Answer 13

image produced by light emission by a fluorescent antibody

Question 14

Chemiluminescence

Answer 14

image produced by light emission from an enzymatic reaction

Question 15

GFP (green fluorescent protein)

Answer 15

small protein from a jellyfish that can be fused to other proteins to visualize them in a living thing

Question 16

Co-Immunoprecipitation

Answer 16

if protein of interest binds other proteins or functions within a complex of proteins, you will also immunoprecipitate the complex