Enzymology

Question 1

CK-MB

Answer 1

Creatine Kinase with MB subunits.

is found in high % of total CK in the heart. (30% CK-MB and 70% CK-MM)

Used as an indicator of MI. Levels peak 24hrs. after MI but is back to baseline by 48hrs.

Question 2

Early Myocardial Infarction Indicators

Answer 2

CK-MB (peaks 24hrs. indicates severity)
Myoglobin increase
Increased Cardiac Troponin I and T levels.

Question 3

Late Myocardial Infarction indicators

Answer 3

cTnI and cTnT
Lactate dehydrogenase (LDH) 1,2 flip

Question 4

Alkaline phosphatase

Answer 4

ALP cleaves phosphate groups from nucleotides (DNA,RNA) and proteins. It is found primarily in liver, bone, intestine and placenta

Obstructive processes induce ALP synthesis and lead to release of ALP into the serum.

Question 5

Alanine aminotransferase

Answer 5

ALT makes pruvate from Ala

Marker for liver damage along with AST. ALT levels are higher than AST except in cirrhosis and ethanol abuse

Question 6

Aspartate aminotransferase

Answer 6

AST makes Oxaloacetate from Asp

AST is a marker for liver damage along with ALT. ALT levels are higher than AST except in cirrhosis and ethanol abuse

Question 7

DFP - Diisopropyl fluorophosphate

Answer 7

Nerve gase

irreversibly inhibits acetylcholinesterase (binds to a Ser) results in over stimulation of acetylcholine

This leads to blurred vision, bronchoconstriction, seizures, respiratory arrest and death

Question 8

Allopurinol

Answer 8

suicide inhibior of xanthine oxidase in uric aid formation

treats gout.

Question 9

Acetyl Salacilic Acid (ASA)

Answer 9

Aspirin

irreversibly inhibits COX1 and COX2

Question 10

Competitive inhibition

Answer 10

structural analog of the enzyme substrate that competes for the active binding site of the enzyme.

results in an apparent Km shift

Question 11

Noncompetitive inhibition

Answer 11

inhibitor does not bind to the active site, but elsewhere on the enzyme distorting the enxyme shape. can become irreversible if a covalent bond forms.

results in a lower Vmax

Question 12

Markers or liver cirrhosis

Answer 12

an AST/ALT ratio >2

Elevated GGT and ALP1

Question 13

Markers for billiary tree disease

Answer 13

ALP, GGT

Question 14

Markers for ethanol abuse

Answer 14

AST/ALT ration >2, Hight GGT for chronic abuse

Elevated GGT for acute abuse

(an alpha amylase / Lipase ratio >2 is indicative of ethanol induced pancreatitis)

Question 15

Marker for Bone disease

Answer 15

ALP (absence of GGT)

Question 16

Markers for pancreatitis

Answer 16

increase serum in alpha-amylase

Question 17

Liver, testicular, and Ovarian cancer

Answer 17

Elevated Alpha-fetoprotein

Question 18

Prostate Cancer

Answer 18

Prostate specific antigen test (PSA-test)