Chemistry Internship Study Questions Section 1

Define International Unit of Enzyme Activity
Amount of Enzyme that produces 1 umol of product/minute under standardized conditions
Given the same reaction time, what effect will a 10 degree rise in temperature have on enzymatic test results?
Double Results
True or False:
Temperature too HIGH will cause enzymes to denature
True
True or False:
Temperature too LOW will stop the reaction
True
Given the same reaction time, what effect will a 10 degree drop in temperature have on enzymatic test results?
1/2 the results
What is meant by zero order kinetics?
Substrate is provided in excess
What is the final reaction product of zero order kinetics dependent on?
Enzyme Concentration
Which enzymes will be falsely elevated if a sample is hemolyzed?
LD, ACP, ALP, AST
In which enzyme test may hemolysis interfere to cause a falsely DECREASED result?
Lipase
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Liver Function
AST, ALT, GGT, LD, ALP
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Cardiac Function
CK, CKMB, AST
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Pancreatitis
AMS, LPS
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Skeletal Muscle Injury/Disease
CK, AST
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Biliary Obstruction
GGT, ALP
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Bone Disease
ALP
What Enzyme OR PANEL of Enzymes is commonly used to evaluate the following:
Organophosphate Poisoning
PCHE
What enzyme is the MOST SENSITIVE indicator of Alcohol Ingestion
GGT
If a GGT is Normal, and the ALP is Increased, what is the probably organ source?
Bone
If a ALT is Normal, and the AST is Increased, what is the probably organ source?
Muscle/Heart
In which Disease are the HIGHEST Levels of AST/ALT Seen?
Hepatitis
AMI, Liver Disease, Pulmonary Infarction, and Pernicious Anemia will all cause an INCREASE in Which Enzyme?
LD
Why must a patient’s age be considered when interpreting ALP results?
Adolescents have INCREASED levels due to NORMAL Bone Growth
In what other “normal” condition is an ELEVATED ALP Observed?
Pregnancy
– produced by the placenta
What is the clinical usefulness for running an Ostase test?
Bone specific;
Determines response to therapy for osteoporosis in post-menopausal women
What specific assay has REPLACED the ACP for evaluation of possible PROSTATE carcinoma?
PSA
What legal significance might an ACP level have if detected on a vaginal swab?
Positive Result is indicative of the presence of seminal fluid
If a specimen for LD cannot be analyzed right away, Why should it NOT be stored in the Fridge?
It is Cold Labile;
Causes a False Decreased Value
List the order of appearance of Cardiac Markers following an AMI
1. Myoglobin
2. Troponin I / CKMB
3. Troponin T
Which cardiac marker is MOST SPECIFIC for Cardiac Tissue?
Troponin
Which cardiac marker is also Markedly Elevated in cases of Skeletal Muscle Trauma?
Myoglobin
What is the formula for the CK Relative Index?
(CKMB x 100) / (Total CK)
What info does the CK-Relative Index provide?
Differentiates CKMB from heart vs CKMB from Muscle
Which cardiac marker is used to diagnose / monitor congestive heart failure?
BNP
In regards to cardiac testing, what is the purpose of performing hsCRP?
To predict future coronary events
What is the purpose of measuring N-telopeptide?
Indicator of bone resorption