Proteins

Question 1

Primary Structure

Answer 1

the number and types of amino acids in the specific amino acid sequence

Question 2

Hemoglobin S

Answer 2

substitution of valine for glutamic acid in the alpha chain of Hemoglobin A. Causes Sickle Cell Anemia

Question 3

Secondary Structure

Answer 3

structures stabilized by hydrogen bonds between amino acids within the protein. Common secondary structure are alpha helix, beta pleated sheet, and turns; add strength and flexibility to protein

Question 4

Tertiary Structure

Answer 4

overall shape or conformation of protein; known as the fold (spatial relationship of secondary structures); 3D and involve interactions of side chains stabilized through hydrophobic effect, ionic attraction, hydrogen bonds, and disulfide bonds; equates to function and chemical properties

Question 5

Quaternary structure

Answer 5

shape or structure that results from interaction of more than one protein molecule

Question 6

pI

Answer 6

Isoelectric point; if pH is greater than pI, proteins are negatively charged; if pH is less than pI, proteins are positively charged

Question 7

denaturation

Answer 7

loss of native, or naturally occurring, folded structure of the protein

Question 8

anabolism

Answer 8

protein synthesis

Question 9

catabolism

Answer 9

protein breakdown

Question 10

Plasma proteins

Answer 10

albumin and globulins

Question 11

Prealbumin

Answer 11

(transthyretin) migrates before albumin in classic protein electrophoresis; transport protein for thyroid hormones; thyroxine (T4); and triiodothyronine (T3); rich in tryptophan and complex with retinal binding protein to transport retinol;

Question 12

Prealbumin normal range

Answer 12

0.1-0.4 g/L in adults

Question 13

Prealbumin decreases

Answer 13

hepatic damage; acute-phase inflammatory response; tissue necrosis; poor nutritional status

Question 14

Prealbumin increase

Answer 14

steroid therapy; alcohol abuse; chronic renal failure

Question 15

Albumin

Answer 15

most abundant protein in plasma; binds and transports substances in the blood, ie thyroid hormones, unconjugated bilirubin, fat-soluble hormones, iron, fatty acids, calcium, magnesium, and drugs such as aspirin; glycated albumin as sensitive indicator of short-term hyperglycemic control over 1 month.

Question 16

Albumin decrease

Answer 16

acute inflammatory response; liver and kidney disease; malnutrition and/or malabsorption

Question 17

Albumin increase

Answer 17

seldom clinically important

Question 18

Albumin normal range

Answer 18

35-55 g/L in adults

Question 19

Globulins

Answer 19

alpha1, alpha2, beta, and gamma

Question 20

alpha 1 antitrypsin

Answer 20

glycoprotein; inhibition of protease; neutrophil elastase; mutations in SERPINA1 gene cause deficiency in alpha1 antitrypsin or an abnormal form; accounts for 90% of alpha1 globulin fraction; migrates immediately following albumin

Question 21

alpha1 antitrypsin normal range

Answer 21

2-4 g/L in adults

Question 22

alpha1 antitrypsin increases

Answer 22

inflammatory reactions; pregnancy and contraceptive use;

Question 23

increase in alpha1 antitrypsin abnormal form

Answer 23

cirrhosis

Question 24

alpha1 antitrypsin decreases

Answer 24

homozygous ZZ individual greatest risk for hepatic and pulmonary disease; identified in lab by lack of band on serum protein electrophoresis; confirmation done by radial immunodiffusion and automated immunonephelometric assays

Question 25

alpha1-fetoprotein

Answer 25

synthesized in utero by developing embryo; decrease gradually after birth; may protect the developing embryo from immunologic attack by the mother;

Question 26

alpha1 fetoprotein normal range

Answer 26

1x10^5 g/L

Question 27

increased fetoprotein

Answer 27

spina bifida; neural tube defects; abdominal wall defects; anencephaly, general fetal distress; twins

Question 28

decreased fetoprotein

Answer 28

trisomy 21 and trisomy 18