Unit 1

Question 1

What are two major groups of identifying proteins?

Answer 1

(1) protein labeling

(2) protein tracking

Question 2

What are four examples of protein labeling?

Answer 2

(1) radioactivity
(2) fluorescence
(3) chemical tags (His Myc)
(4) chemical cross linking

Question 3

How are protein tracking v. protein labeling distinguished?

Answer 3

protein labeling - tell different types of proteins apart

protein tracking - find where protein is

Question 4

what are five strategies of protein tracking?

Answer 4

visual
(1) FACS
(2) microscopy
biochemical
(3) size
(4) charge
(5) enzymatic assays

Question 5

what are four ways of protein size separation?

Answer 5

(1) SDS page
(2) liquid gel chromatography
(3) differential centrifugation
(4) density grade centrifugation

Question 6

what are compartmental enzymes?

Answer 6

all of the closed parts within the cytosol of a eukaryotic cell, usually surrounded by a single or double lipid layer membrane. These compartments are often, but not always, defined as membrane enclosed regions. The formation of cellular compartments is called compartmentalization.

Question 7

what are three membrane bound organelles involved in protein processing

Answer 7

(1) nucleus
(2) ER
(3) Golgi appartus

Question 8

what are four other organelles?

Answer 8

(1) peroxisome
(2) endosome
(3) lysosome
(4) vacuoles

Question 9

what is the function of the smooth ER?

Answer 9

lipid generation and detoxification of hydrophobic chemicals

Question 10

what is the function of the rough ER?

Answer 10

protein synthesis, folding and quality control (including degradation)

Question 11

what are two other functions of the ER

Answer 11

(1) lipid donation to other organelles

(2) Ca2+ homeostasis

Question 12

What is the purpose/strength of the Western blot?

Answer 12

(1) use specific Abs to probe for P of interest after SDS-PAGE
(2) very common technique to determine presence of specific P

Question 13

What are two weakness of Western blot?

Answer 13

(1) background depending on Ab

(2) follows SDS-PAGE, time comsuming

Question 14

What is the purpose/strength of the IP?

Answer 14

(1) clean WB by pre-selection

(2) co-IP proteins bound with IP to be collected and rung on SDS page

Question 15

Brightfield MS?

Answer 15

not very useful for in depth question

Question 16

Fluorescent MS, pros and cons?

Answer 16

(+) useful in determining where P is

(-) very difficult determine exactly which compartment that P is in

Question 17

EM MS, pros and cons?

Answer 17

(++) even more useful in telling where P is

(-) long time, difficult,cyro even harder

Question 18

How can unstained living cells be visualized?

Answer 18

phase contrast microscope and DIC differential interference constrast

Question 19

What is phase contrast microscopy primary used for and what no?

Answer 19

examining location and movement of larger organelles

works for single cells and thin layers but not thick layers

Question 20

What two additional parts does phase contrast microscope have to work?

Answer 20

(1) phase plate in the objective

(2) annular diaphragm

Question 21

What can DIC do?

Answer 21

see extremely small details and thick objects

Question 22

What is typical for preparing specimens to be observed with light microscope?

Answer 22

(1) fix with chemical cross linking
(2) embed on paraffin or plastic
(2) section with mircotome
(3) stain with chemical dye

Question 23

What are steps to prepare sample for observation by fluorescent microscope?

Answer 23

(1) chemically fix and make permeable
(2) incubate primary Ab and wash
(3) incubate with secondary Ab and wash
(4) mount on specialized mounting medium

Question 24

How does DIC work?

Answer 24

gradient of refractive index of two beams across speciman

Question 25

How does phase contrast work?

Answer 25

variations in thickness or thinness across speciman

Question 26

What does DIC stand for?

Answer 26

differential interference contrast