Bishop Chapter 11 Amino Acids and Proteins

Question 1

The two major groups of plasma proteins

Answer 1

Albumin and Globulins

Question 2

Analysis of blood specimens will typically include what four protein measurements?

Answer 2

Total protein, albumin, globulins, and albumin-to-globulin ratio (A/G) ratio.

Question 3

What is the alternative name for prealbumin?

Answer 3

Transthyretin

Question 4

What is the reason for giving transthyretin the name prealbumin?

Answer 4

It migrates before albumin in classic serum protein electrophoresis (SPE).

Question 5

Prealbumin acts as a transport protein for which thyroid hormone(s)?

Answer 5

Thyroxine and Triiodothyronine

Question 6

Prealbumin forms a complex with which vitamin for transport?

Answer 6

Forms a complex with retinol-binding protein for transport of retinol (Vitamin A).

Question 7

Prealbumin is rich with which amino acid?

Answer 7

Tryptophan

Question 8

What would cause a decrease in serum prealbumin?

Answer 8

Hepatic damage due to decreased protein synthesis, during an acute-inflammatory response, or as a result of tissue necrosis.

Question 9

How would poor nutritional status effect prealbumin?

Answer 9

Low prealbumin level

Question 10

When would serum prealbumin be elevated?

Answer 10

Patients receiving steroid therapy, issues with alcohol abuse, or who are in chronic renal failure.

Question 11

What protein is the most abundant in plasma?

Answer 11

Albumin

Question 12

What is the rate at which albumin is synthesized?

Answer 12

9 to 12 g/day

Question 13

What does albumin exist in other than in serum?

Answer 13

Extravascular (interstitial) space.

Question 14

The total amount of extravascular albumin exceeds the total intravascular amount by how much?

Answer 14

30%

Question 15

What is the transcapillary escape rate?

Answer 15

The rate at which intravascular albumin leaves the bloodstream per hour.

Question 16

What is the clinical significance of albumin?

Answer 16

The transport of thyroid hormones, unconjugated bilirubin, fat-soluble hormones, iron, fatty acids, calcium, magnesium, and certain drugs such as aspirin.

Question 17

Decreased blood concentrations of albumin are most commonly associated with what conditions?

Answer 17

Acute inflammatory response; liver disease; kidney disease.

Question 18

What condition causes an increase excretion of albumin?

Answer 18

Nephrotic syndrome.

Question 19

What is the clinical significance of high blood albumin?

Answer 19

Not clinically significant; can be the result of dehydration or excessive albumin infusion.

Question 20

What is the main function of alpha1-Antitrypsin?

Answer 20

The inhibition of the protease, neutrophil elastase.

Question 21

In which cells is neutrophil elastase released?

Answer 21

Leukocytes

Question 22

How is the lack of alpha1-antitrypsin typically identified?

Answer 22

By the lack of alpha1-globulin band on serum protein electrophoresis.

Question 23

What is the clinical significance of alpha1-fetoprotein?

Answer 23

Proposed that it protects the developing fetus from immunologic attack by the mother.

AFP can also be used as a tumor marker.

Question 24

What is the primary function of haptoglobin?

Answer 24

To bind free hemoglobin to prevent the loss of its constituent, iron, into the urine.

Question 25

Haptoglobin concentrations are primarily used to evaluate what condition?

Answer 25

Hemolytic anemia

Question 26

If the haptoglobin concentration is normal and the reticulocyte count is increased, what is likely the cause of this?

Answer 26

Anemia is due to destruction of red blood cells in organs such as the spleen and liver.

Question 27

If haptoglobin concentration are decreased without any sign of hemolytic anemia, what is the likely cause?

Answer 27

It is possible the liver is not producing adequate amounts of haptoglobin.

Question 28

Ceruloplasmin is primarily measured along with what to diagnose Wilson's disease?

Answer 28

Blood and urine copper tests.

Question 29

What is Wilson's disease?

Answer 29

An autosomal recessive inherited disorder associated with decreased concentrations of ceruloplasmin.

Question 30

Decreased concentrations of ceruloplasmin can cause what condition(s)?

Answer 30

Hepatic cirrhosis and neurologic damage.

Question 31

What is the clinical significance of transferrin?

Answer 31

Binds and transports iron to its storage sites (i.e. liver), where it is incorporated into apoferritin, which forms ferratin.

Question 32

Transferrin concentrations are routinely measured to determine what conditions?

Answer 32

Anemia, gauge iron metabolism, and to determine the iron-carrying capacity of the blood.

Question 33

Transferrin concentrations are abnormally elevated in what condition(s)?

Answer 33

Iron deficiency anemia.

Question 34

Low transferrin concentrations can lead to what conditions?

Answer 34

Impair hemoglobin production which leads to anemia.

Question 35

What precipitates in tissue as a result of inappropriate accumulation and precipitation of iron?

Answer 35

Hemosiderin

Question 36

When does transferrin produce a low result?

Answer 36

Liver disease or not enough protein in the diet.

Question 37

Define atransferrinemia.

Answer 37

An autosomal recessive trait due to mutation of both transferrin genes, with a resulting absence of transferrin.

Question 38

How does iron deficiency effect the following analytes: Total serum Iron, total iron-binding capacity, and transferrin saturation.

Answer 38

Total serum iron: DECREASED Total iron-binding capacity: INCREASED Transferrin saturation: DECREASED

Question 39

Lipoproteins are complexes of proteins and lipids whose function is to do what?

Answer 39

Transport cholesterol, triglycerides, and phospholipids in the bloodstream.

Question 40

What causes elevated serum levels for beta-2-microglobulin?

Answer 40

The result of impaired clearance by the kidney or overproduction of the protein that occurs in a number of inflammatory diseases.

Question 41

The complement system is a natural defense mechanism that does what?

Answer 41

Protects the human body from infections.

Question 42

What condition(s) are indicative of increased C3 and C4 levels?

Answer 42

Acute inflammatory disease and tissue inflammation.

Question 43

What condition(s) are indicative to decreased levels of complement C3?

Answer 43

Autoimmune disease, neonatal respiratory distress syndrome, bacteremia, tissue injury, and chronic hepatitis.

Question 44

What condition(s) are indicative of decrease complement C4 levels?

Answer 44

Disseminated intravascular coagulation (DIC), acute glomerulonephritis, chronic hepatitis, and SLE.

Question 45

What is the function of fibrinogen?

Answer 45

To form fibrin clot when activated by thrombin.

Question 46

Decreased levels of fibrinogen is indicative of what?

Answer 46

Extensive coagulation, during which fibrinogen is consumed.

Question 47

What condition(s) causes an elevated C-Reactive Protein (CRP)?

Answer 47

Atherosclerosis (fatty deposits accumulating in the inner lining of the arteries).

Question 48

hsCRP is most commonly used to detect what condition?

Answer 48

Cardiovascular Disease

Question 49

What is the most abundant class of antibodies found in both plasma and lymph?

Answer 49

IgG

Question 50

IgG antibodies act on what?

Answer 50

Bacteria, fungi, viruses, and foreign particles by agglutination, opsonization, and complement activation and by neutralizing toxins.

Question 51

IgG is increased in which conditions?

Answer 51

Liver disease, infections, IgG myeloma, parasitic disease, and rheumatic diseases.

Question 52

Decreased IgG levels are associated with what conditions?

Answer 52

Acquired immunodeficiency, hereditary deficiency, and non-IgG myeloma.

Question 53

Where does secretory IgA remain active?

Answer 53

In the digestive and respiratory tracts.

Question 54

In what condition(s) is serum IgA increased?

Answer 54

Liver disease, infections, and autoimmune diseases.

Question 55

Myoglobin is the primary oxygen-carrying protein found where?

Answer 55

In striated skeletal muscle and cardiac muscle.

Question 56

Cardiac troponins are considered the "gold standard" for diagnosis of what syndrome?

Answer 56

Acute Coronary Syndrome (ACS)

Question 57

Fetal fibronectin (fFN) is used to help predict what?

Answer 57

The short-term risk of premature delivery.

Question 58

Where is fFN produced?

Answer 58

At the boundary between the amniotic sac and the lining of the uterus.

Question 59

What types of samples are unacceptable for serum total protein testing?

Answer 59

Hemolyzed specimens.

Question 60

What total protein quantitation method measures the amount of nitrogen in the specimen?

Answer 60

Kjeldahl

Question 61

Why is the Kjeldahl method no longer used in clinical laboratories?

Answer 61

It is time consuming and relies on some assumptions that are not always true.

Question 62

What total protein quantitation method is most commonly used in clinical laboratories?

Answer 62

Biuret

Question 63

What is the principle of the Biuret reaction?

Answer 63

Based on the principle that in an alkaline medium and the presence of at least two peptide bonds, cupric ions (Cu2+) will complex with groups involved in the peptide bond to form a violet-colored chelate.

Question 64

During the Biuret reaction, at what absorbance is the colored chelate measured?

Answer 64

540 nm

Question 65

During the Biuret reaction, the absorbance is proportional to what?

Answer 65

The number of peptide bonds present which reflects the total protein concentration of the specimen.