Unit 3 - Protein

Question 1

Primary Structure

Answer 1

Amino acid sequence determined by DNA

Question 2

Secondary structure

Answer 2

more complex a.a. chain

Question 3

Tertiary structure

Answer 3

Complex folding, 3D structure

Question 4

Quaternary Structure

Answer 4

More than on protein chain

Question 5

When is biological activity lost in a protein?

Answer 5

When secondary/tertiary/quaternary structure denatured

Question 6

Simple protein

Answer 6

No other major chemical class associated with them

Question 7

Conjugated proteins

Answer 7

Nonamino acid chemical associated with protein
(prosthetic group)

Question 8

Lipoprotein

Answer 8

proteins with fat
(cholesterol, triglyceride, phospholipids)

Question 9

Metalloproteins

Answer 9

Contain a metal
(hemoglobin)

Question 10

Glycosylated proteins

Answer 10

Contain carbohydrate
(HgbA1c)

Question 11

Types of measurement methods

Answer 11

Light absorption
Light refraction
Dye bonding/Colorimetric
Electrophoresis

Question 12

215nm

Answer 12

Peptide bond

Question 13

280 nm

Answer 13

Aromatic rings present in a.a.

Question 14

What proteins are detected at 280 nm?

Answer 14

Tyrosine
Tryptophan
Phenylalanine

Question 15

What measurement method is best for a known or pure protein?

Answer 15

Light absorption

Question 16

What measurement method is nondestructive for proteins?

Answer 16

Light absoprotion

Question 17

What is a total protein measurement that is rapid?

Answer 17

Light refraction

Question 18

What specimen is worst for light refraction?

Answer 18

CSF
Low protein specimen

Question 19

What are the physical properties used to detect and measure proteins

Answer 19

Molecular size
Electrical charge
Solubility

Question 20

What affects electrical charge?

Answer 20

pH

Question 21

How does solubility measure proteins

Answer 21

A protein is dissolved or precipitated out of a mixture

Question 22

What is used to manipulate solubility

Answer 22

SUlfosalicylic acid

Question 23

What does increased turbidity mean for a solubility sample?

Answer 23

More protein was precipitated out

Question 24

What are the major components of biuret?

Answer 24

Sodium Hydroxide + Copper sulfate

Question 25

What dye bonding test is used to measure total protein

Answer 25

Biuret

Question 26

What dye bonding test is used to measure albumin?

Answer 26

BCG BCP

Question 27

How does biuret work to bond to the protein?

Answer 27

Copper ions react with carbonyl oxygen and amide nitrogen in peptide bond

Question 28

How many peptide bonds are required for biuret analysis?

Answer 28

At least two

Question 29

Are dipeptides measured by biuret ?

Answer 29

No, two amino acids with one peptide bond

Question 30

What is a positive color change for biuret?

Answer 30

Blue biuret makes a violet color with protein

Question 31

Color intensity increases as ___ increases

Answer 31

Peptide bonds amount

Question 32

Total protein reference range in serum

Answer 32

6-8 g/dL

Question 33

What's the difference in tp concentration from serum and other fludis

Answer 33

Serum has highest concentration, others are measured in mg or ng quantities

Question 34

When would a pink color be produced in biuret method

Answer 34

In presence of small peptides

Question 35

How is biuret calibrated?

Answer 35

With albumin alone because other protein concentrations are too diverse and unpredictable

Question 36

What samples are not appropriate for biuret

Answer 36

CSF Urine

Question 37

What dye is used to measure lower protein levels like in CSF or Urine

Answer 37

Coomasie Blue Ponceau S Amido black Pyrogallol red

Question 38

When is insensitivity in dye bonding for globulins NOT a problem?

Answer 38

A leaky glomerulus in the kidney because albumin spills into urine

Question 39

When is insensitivity in dye ending for globulins a problem?

Answer 39

Multiple myeloma because free light chains spill into urine

Question 40

Which test would you choose for clinical decisions based on serum albumin? BCG or SPE?

Answer 40

BCG/BCP

Question 41

Total Protein formula

Answer 41

Alb + Glob

Question 42

Globulin formula

Answer 42

TP - Albumin

Question 43

A/G ratio

Answer 43

Albumin divided by globulin

Question 44

Albumin reference range in serum

Answer 44

3.5-5 g/dL

Question 45

Globulins reference range in serum

Answer 45

2.5-3 g/dL

Question 46

Protein reference range in urine

Answer 46

1-14 mg/dL <100 mg/24 hours

Question 47

Protein reference range in CSF

Answer 47

15-45 mg/dL Note small window

Question 48

Calculation of protein in urine using 24 hours specimen

Answer 48

(given total protein mg/dL divided by 100mL) = (xmg/given total mL)

Question 49

What urine specimen eliminated biological variation and dilution effects?

Answer 49

24 hour urine

Question 50

Why would 24 hour urine be required?

Answer 50

Evaluate urine and eliminate biological variation and dilution effects

Question 51

What is the point where the number of positive charges equal the number of negative charges?

Answer 51

Isoelectric point

Question 52

If the isometric point of albumin is 4.6, what is its charge at 4.6?

Answer 52

No net charge Neutral

Question 53

Albumin Iso point is 4.6, what is its charge at 5.1

Answer 53

Positive charge

Question 54

What is the isoelectric point of globulins

Answer 54

5.1-6.2

Question 55

Which protein has the highest net negative charge at a buffer pH of 8.6

Answer 55

Albumin

Question 56

What is the usual pH of the buffer for SPE

Answer 56

8.6

Question 57

Anode

Answer 57

Positive pole

Question 58

Cathode

Answer 58

Negative pole

Question 59

Where do anions move?

Answer 59

To the anode

Question 60

Where do cations move?

Answer 60

To the cathode

Question 61

The more the negative charge, the __ the movement?

Answer 61

faster

Question 62

What causes the visible application point on SPE?

Answer 62

Precipitated protein from a thawed specimen or debris

Question 63

A molecule has no charge, where will it move in an electrical field?

Answer 63

Nowhere

Question 64

What does the buffer make the molecules do?

Answer 64

Take on a negative charge to move towards the anode

Question 65

Where is the origin of the application point?

Answer 65

Cathode, negative pole

Question 66

Fast equivalent to

Answer 66

Positive end

Question 67

Slow equivalent to

Answer 67

Negative end

Question 68

Frictional coefficient

Answer 68

Medium resists particle movement

Question 69

how do larger, more complex molecules move if the pores in the medium are small?

Answer 69

Slowly

Question 70

If the support medium has small pores, what is separation based on?

Answer 70

Size and charge

Question 71

If the support medium has large pores, what Is separation based on?

Answer 71

Charge only

Question 72

High voltage can cause

Answer 72

High temps that denature proteins

Question 73

Usually, the slab or room should be...

Answer 73

Cold

Question 74

What is the standard buffer for SPE?

Answer 74

Sodium barbital required for electrons to flow

Question 75

What kind of ionic strength do you want your buffer to have?

Answer 75

Low, the extra ions will impede migration by adding charge

Question 76

What is wick flow caused by

Answer 76

Evaporation of the buffer

Question 77

What does wick flow look like

Answer 77

Proteins make a trail

Question 78

How do you fix wick flow

Answer 78

Cool the system or buffer Keep lid on electrophoresis chamber Change buffer/use new buffer every time

Question 79

What is electroendosmosis

Answer 79

Weak anions bump into strong cations and move behind the application point

Question 80

Tracer dyes

Answer 80

Stick to albumin and make the band look fat

Question 81

Two albumin bands can be caused by

Answer 81

Genetic bisalbuminemia or Drugs

Question 82

Why would drugs cause two albumin bands

Answer 82

They can bind to the albumin

Question 83

Split beta bands have

Answer 83

Transferrin and C3

Question 84

If a split beta gel wasn't being used, what would the C3 band make you think?

Answer 84

If the peak is a monoclonal spike or If specimen is fresh

Question 85

What does fresh specimen look like eon SPE?

Answer 85

Monoclonal spike in beta band, split beta band

Question 86

What does fibrinogen do to SPE

Answer 86

Looks like a spike if plasma used

Question 87

Where does fibrinogen migrate to on SPE

Answer 87

Between beta and gamma

Question 88

How to solve the spike caused by fibrinogen?

Answer 88

Allow serum to fully clot Add thrombin so blood will clot (if can't be recollected)

Question 89

Where does hemolysis appear on SPE?

Answer 89

Between a2 and B

Question 90

What Ig are most commonly seen on SPE?

Answer 90

G, A, M

Question 91

Why aren't IgD or IgE seen on SPE?

Answer 91

Too low concentration, unless monoclonal

Question 92

Where does CRP appear on SPE

Answer 92

Gamma region toward beta side

Question 93

When would CRP be elevated on SPE?

Answer 93

Acute phase reactant May mimic monoclonal spike

Question 94

Isoelectric focusing

Answer 94

Electrophoresis done in pH gradient

Question 95

How does isoelectric focusing work

Answer 95

Proteins stop moving when they reach the pH of their isoelectric point