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302 Cards in this Set

  • Front
  • Back
Lipids are soluble in ______ but insoluble in _______
organic solvents, water
Lipids yield ______ or ______ on hydrolysis
fatty acids or complex alcohols
Four major functions of lipids
biological membranes

efficient way to store excess calories

provide readily available energy reserves

serve as essential vitamins and hormones
Fatty acids have what type of structure?
In nature, most fatty acids are ____ and have an ______ number of carbon atoms
unsaturated, even
Structure of triglycerides
glycerol backbone with three fatty acids attached
Most of the lipids that are obtained in the diet are _______
What type of bond is formed between the carboxylic acid of the fatty acid and the hydroxyl group of the glycerol backbone in triglycerides?
ester bond
Phospholipid structure
2 esterified fatty acids (bound to glycerol) + phosphate + polar head group
Cholesterol is a good source of energy (T/F)
False, it is not easily broken down.
Bile acids are more ______ than cholesterol
Bile acids act as _______ in the intestine to break down ______.
emulsifiers/detergents, dietary fat
Lipoproteins are less water soluble than lipids (T/F)
False, lipoproteins are more soluble due to the charge of the amino acids in the protein portion
Which human plasma lipoprotein has the highest amount of protein?
HDL is also known as ______ lipoprotein
LDL is also known as _______ lipoprotein
In a lipoprotein, more lipid means greater _______ and lower _______
size, density
In order to be transported in blood, lipids must combine with ________
water-soluble compounds such as apolipoproteins
Triglyceride must always be on the inside of lipoproteins because __________
of their very hydrophobic nature
Low-density lipoproteins are derived from _________
VLDL by lipolysis
What is lipoprotein (a)?
LDL-like particles that are heterogeneous in size and density. They resemble plasminogen in structure and interfere with fibrinolysis. High plasma levels indicate higher risk for cardiovascular disease.
High-density lipoprotein is capable of removing _________
excess cholesterol from peripheral cells
Apoproteins C and E are released when ______
lipoprotein lipase forms LDL from VLDL
Apoproteins associated with chylomicrons
B48, C1-C3, E
Apoprotein associated with LDL
VLDL apoproteins
B100, C1-C3, E
HDL apoproteins
A1, A2, C1-C3, E
IDL apoprotein
Functions of apoproteins (for lipids)
Activate enzymes involved in lipid metabolism, maintain structural integrity of lipid/protein complex, delivery of lipids to cells via recognition of cell surface receptors
Four major pathways in lipoprotein metabolism
Lipid absorption, Exogenous pathway, Endogenous pathway, Reserve cholesterol transport pathway
Cholesteryl ester is hydrolzed by cholesterol esterase (pancreatic secretion) to form _________ and _______.
free cholesterol, free fatty acid
Triglycerides must be ______ before passing through the intestinal membrane
hydrolyzed by lipase to free glycerol and fatty acids
Lipase cannot directly attack triglyceride because of difference in ______
charge, lipase is hydrophilic while triglyceride is hydrophobic

(bile acids solve this problem by forming micelles)
Once the fatty acids and glycerol are inside the intestinal cell, _____ are reformed and combines with apoproteins to form _______
triglycerides, chylomicrons
Chylomicrons are transferred from intestinal cells to the _______
lymphatic vessels
All lipoprotein generated by the liver is in the form of _______
Function of lecithin cholesterol acyltransferase. What is an important cofactor for this enzyme?
Esterifies a fatty acid to a cholesterol molecule to allow import into cells. Apoprotein A-1.
the deposition of lipids in various tissues within the body
Risk factors for atherosclerosis
>45 years men, >55 years women, family history, cigarette smoking, hypertension, diabetes mellitus, low HDL level, high LDL level, high total cholesterol, severe obesity, physical inactivity, stress
Laboratory guidelines for desirable lipid levels
Total cholesterol < 200 mg/dL
LDL < 100 mg/dL
HDL > 60 mg/dL
Triglyceride level is not directly associated with risk of cardiovascular disease, but the recommended level is _______
< 150 mg/dL
Lipoprotein (a) desired level
<30 mg/dL

(independent risk factor)
How does lipoprotein (a) contribute to cardiovascular disease?
Lp(a) has a structure very similar to plasminogen, and competes with plasminogen for activators, blocking their action. Plasmin is therefore unable to form and lyse clots.
High HDL levels are associated with what populations?
pre-menopausal women, people who exercise regularly, people with a low but healthy weight.
Insulin, estrogen and thyroxine have what relationship with total cholesterol levels?
How do statin drugs work?
They inhibit HMG-CoA reductase (an enzyme which converts acetyl coA to cholesterol). This increases HDL and reduces LDL.
How do fibrate drugs work?
Activate LPL, promote rapid VLDL turnover, decrease VLDL secretion

However, these drugs are somewhat toxic to the liver
Cholestyramine decreases plasma cholesterol by ________
binding bile acids to prevent reabsorption by the liver

Not very well tolerated
elevation of low density and high density lipoproteins

Primary: inborn error of metabolism
Seconday: diabetes, hormone replacement, nephrotic syndrome, hepatic disorder, blood pressure medication
Hypertriglyceridemia primarily results from __________
lipoprotein lipase deficiency
The portal triad consists of
a vein, an artery and a bile duct
Reticuloendothelial cells break down hemoglobin into ________
Indirect or unconjugated bilirubin is bound to ________
Bilirubin diglucuronide is known as _________
conjugated or direct bilirubin
Urobilinogen may be excreted in ______
urine or feces
excess bilirubin in body, can produce yellow pigment in skin or eyes
Excess unconjugated bilirubin in brain tissue
Delta bilirubin is ________
a type of conjugated bilirubin that is bound to albumin covalently
Unconjugated bilirubin is never excreted by the ______. This is because __________.
kidney, the albumin molecule is too large to pass through the glomerulus
Prehepatic jaundice is caused by _________.
increased hemoglobin breakdown (i.e. hemolytic anemia, shortened hemoglobin lifespan, pernicious anemia)
Prehepatic jaundice laboratory results
indirect bilirubin increased
direct bilirubin normal

direct bilirubin negative
urobilinogen increased

urobilinogen increased
Hepatic jaundice laboratory results (due to cell damage)
increased indirect bilirubin
increased direct bilirubin

positive direct bilirubin
increased urobilinogen

variable urobilinogen
Posthepatic jaundice laboratory results
increased indirect bilirubin
increased direct bilirubin

direct bilirubin positive
decreased to negative urobilinogen

decreased to negative urobilinogen
Causes of hepatic jaundice
Conjugation failure, transport failure, cell damage
Cause of post-hepatic jaundice
obstruction of the bile duct
Specimen requirements for bilirubin assay
protected from light, serum/heparinized plasma, not hemolyzed
The most common elevated element in hypercholesterolemia is _______ secondary to other disease
LDL cholesterol
Familial hypercholesterolemia is due to a defect or deficiency in ________
LDL receptos
Familial hypercholesterolemia results in an increased risk for ________
The treatment of choice for familial hypercholesterolemia is ______ because they decrease _______ LDL and increase _______
statin drugs, endogenous, LDL receptors
Triglceridemia may occur secondary to ______
diabetes mellitus or hormonal abnormalities
Severe hypertriglyceridemia may occur due to deficiency of ____ or _____
LPL, apoprotein CII
When LPL is absent, increased levels of chylomicrons cause lipemia even in fasting states (T/F)
True, serum triglyceride levels may exceed 500 mg/dL
Combined hyperlipoproteinemia consists of what?
presence of increased serum cholesterol and triglyceride
Familial combined hyperproteinemia is due to an overproduction of _____ and _____
VLDL and B100
Familial dysbetalipoproteinemia is due to _________ and results in increased _______ and _______
presence of a rare form of apoE, VLDL, chlyomicron remnants
Hypoalphalipoproteinemia is caused by
decrease in HDL exhibited from absence or non-detectable levels of apo A-1.
The sample of choice for analysis of lipids is ______

plasma with lithium heparin may also be used
What is the minimum fast for a triglyceride sample?
12 hour fast
Is fasting necessary for cholesterol analysis?
No, however fasting is necessary if a lipid panel is being performed
Chylomicrons will be distributed throughout a serum sample (T/F)
False, chylomicrons will generally float to the top. This is helpful in determining if a sample is fasting or not. Additionally, it is important to mix the sample well before analysis for this reason.
HDL cholesterol analysis requires isolation of HDL by _______ of LDL/VLDL followed by ________. The supernatant HDL may then be measured with the same method as _______.
precipitation, centrifugation, total cholesterol
An alternative method of isolating cholesterol from HDL involves treatment of the serum with ______, which lyses HDL but _____ LDL and VLDL without lysis.
a detergent, coats
Friedewald formula
total cholesterol = HDL + LDL + VLDL

as long as the sample is fasting (triglyceride < 400 mg/dL)
Measurement methods for LDL
direct immunoassay, ultracentrifugation
In congestive heart failure, liver function is compromised by _______
Conjugated or direct bilirubin is ______ is water
Unconjugated or indirect bilirubin is _______ in water
What enzyme is responsible for bilirubin conjugation?
Uridyldiphosphate glucuronyl transferase
Prehepatic jaundice results in increased ________ bilirubin
Total bilirubin reference range
0.2 to 1.2 mg/dL
Causes of prehepatic jaundice
hemolytic anemia, ineffective erythropoiesis, neonatal physiological jaundice
In prehepatic jaundice, bilirubin levels rarely exceed 5 mg/dL (T/F)
True, this is because the liver is still functioning normally
Unconjugated bilirubin (can/can not) cross the blood-brain barrier
Can, this may result in kernicterus causing severe neurologic damage
Treatment for neonatal physiological jaundice
phototherapy with monochromatic blue like to oxidize bilirubin to more soluble end products to enhance renal excretion
Intrahepatic jaundice
problem is within the liver (impaired uptake, absent/decreased enzyme activity, defective excretion due to absence of transport molecule)

Liver enzymes ALT and AST will be highly elevated compared to LD
Visible icterus occurs above ______ bilirubin
3 mg/dL
Posthepatic jaundice
caused by physical barrier to bile excretion (obstructive, artesia), highly increased conjugated bilirubin, will be excreted in urine

Biliary enzymes will be elevated (GGT and ALP)
Alcoholic jaundice is characterized by
osmolalic increase, very high GGT (as compared to ALP)
LD stands for
Lactate dehydrogenase
If true hepatic disease exists, what enzymes will be increased?
AST, ALT, LD, usually with ALT>AST
Decreased albumin is a very good marker for _______
liver disease
Amino acids are linked to each other through _____ bonds with the ______ group of one amino acid combining with the _______ group of another
peptide, carboxyl, amino
inherited enzyme defects that inhibit metabolism of certain amino acids

cause several medical complications due to build-up of toxic amino acids and byproducts in blood
For amino acid analysis in adults, sample should be collected in a tube containing ______ and should be drawn after a ________.
lithium heparin, 6-8 hour fast
______ may be used as a sample for screening amino acid analysis.
Random urine
Primary structure of a protein is determined by _________
number and types of amino acids and their sequence in the polypeptide chain
Tertiary structure is determined by ________
the way the twisted chains or pleated sheets of amino acids fold back on themselves to form a 3D structure
Zwitterion or ampholyte
amino acid that at physiologic pH has both carboxyl and amino sites ionized
Reference range for protein
6.5-8.3 g/dL
Factors influencing the rate of an enzymatic reaction
pH, temperature, concentration of enzyme
Increased temperature ________ the rate of an enzymatic reaction unless the temperature is too high (greater than 40 degrees celsius) which ________ the protein
increases, denatures
Hydrogen ion concentration changes the ionizable groups on enzymes and ______ the rate of the enzymatic reaction due to a change in ________
decreases, shape of the protein
Most enzymes work best between the pH of ____________. One exception is _______.
7 to 8, gastric enzymes
Ionic strength is the ____________
cumulative concentration of all solutes
Body enzymes are optimized for ______ conditions (osmolality)
isotonic (300 mmol/L)
A change in ionic strength changes the _______ of the medium in an enzymatic reaction, resulting in a _________ of the enzyme, resulting in a _________ rate of reaction.
polarity, change in shape, decreased
Enzymes are measured in terms of _______

international unit per liter = micromoles of substrate used up per minute of incubation per liter
Enzyme concentration (zero order) =
change in absorbance per minute/(extinction coefficient*length of light path) x 10^6 micromoles/mole x dilution factor
Advantages of kinetic enzyme assay
can inspect the data and use only the zero order reaction, can detect and eliminate lag phase or substrate exhaustion
Advantage of one-point enzyme assay
Faster, batching
Name the three isoenzymes of CK and where each is found.
CK-1 (BB) - brain and intestine
CK-2 (MB) - mostly cardiac muscle
CK-3 (MM) - skeletal and cardiac muscle

CK may also be found in the kidney, uterus, thyroid, liver and prostate.
Total CK levels are always increased in ______ and ______. These enzymes are increased ______ the upper limit of normal.
acute myocardial infarction, muscular dystrophy, 50-100x
Reference range of CK
25-170 U/L, slightly higher in men than women
A hemolyzed sample will cause a falsely ______ value for CK due to the presence of ________
increased, AK (similar enzyme)
Isoenzymes of LD and where each is found
LD1 - heart, RBC, kidney
LD2 - heart, RBC, kidney
LD3 - lungs
LD4 - liver/skeletal muscle
LD5 - liver
LD6 - CAD with liver disease
Describe the change in LD in acute myocardial infarction
LD1 > LD2

In health individuals, LD2 > LD1
Reference range for LD
100 - 225 U/L
Aspartate aminotransferase is found in:
liver, cardiac and skeletal muscle
Aspartate aminotransferase increases in
myocardial infarction (peaks @ 24 hours), pulmonary embolism, acute hepatocellular disorders (very high levels), skeletal muscle disorders
Alanine aminotransferase is predominantly in the ______
Alanine aminotransferase is ______ than AST in acute inflammatory conditions of the liver
Oxidation of NADH + H+ results in a _______ in absorbance
Alkaline phosphatase is most significant in ______ and _____ disorders
hepatobiliary, bone
The Regan isoenzyme of ALP is a ________
tumor marker
Reference range for ALP
30-90 U/L (can be as high as 125 depending on what method is used)
Acid phosphatase is specific for the _______
prostate gland
Major significance of ACP is ________. However, it is not _______.
prostatic carcinoma (particularly metastasized carcinoma), specific (mostly used to monitor therapy)
Gamma-glutamyl transferase has clinical applications in ______ and _______ disorders.
liver, biliary.
_______ induces synthesis of GGT.
alcohol abuse
Amylase catalyzes the breakdown of ______ and ______
starch, glycogen
Amylase is utilized in the diagnosis of _________.
acute pancreatitis
Reference range of amylase
35-125 U/L
Lipase hydrolyzes __________
ester linkages of fats to produce alcohols and fatty acids.
An increase in lipase is specific for ________.
Cholinesterase hydrolyzes _______.
esters of choline to destroy poisons or drugs.
Cholinesterase is found in ______, _____ and _______.
liver, heart, white matter of brain
Cholinesterase is a sensitive marker for ___________.
organophosphate poisoning
A decrease in cholinesterase is seen in ________, ______, ______ and _______.
liver disease, starvation, burns and insecticide poisoning,
lack of oxygenation due to interrupted blood flow to an organ
angina pectoris
chest pain from lack of oxygen to the heart muscle

characteristic crushing pain, often radiation to left arm, neck or shoulder blade

accompanied by sweating and "feeling of doom"
abnormal rhythm of heart beat due to abnormal stimulation or interruption of the nerve impulse
myocardial infarction
heart attack, necrosis of cardiac muscles due to interruption in blood flow and oxygen to the heart
hardening, roughing and narrowing of the blood vessels due to fatty plaque accumulation
congestive heart failure
inadequacy of pumping by the heart, decreased circulation of blood
7 classic symptoms of heart disease
dyspnea, chest pain, syncope, edema, cyanosis, fatigue, palpitations
S-T elevation on an ECG is diagnostic for ________, however it is only seen in ______ of patients.
myocardial infarction, 50%
In myocardial infarction _____ > ______ (LD isoenzymes).
LD1 > LD2
CKMB is elevated _______ after myocardial infarction and peaks at _______.
6-8, 18-24
CKMB index =
(CKMB activity/total CK activity) * 100

Reference range 1.5-6%
CKMB levels return to normal _____ after MI.
2-3 days
Troponin I is the most sensitive and specific marker for _______
myocardial infarction
Troponin rises above normal level ______ after myocardial infarction
6-8 hours
Troponin peaks at ______ after myocardial infarction
2-4 days
Myoglobin increases ______ after myocardial infarction
2-4 hours
Myoglobin is an early marker for ______ but it is not ______.
myocardial infarction, specific
CRP is a marker for ______
The level of CRP increases when in relationship to MI?
a few hours to a few days before a heart attack
Increased levels of homocysteine have recently been recognized as a _______
cardiac risk factor
An increase in homocysteine is correlated with _______
damage to the endothelial lining of blood vessels
In congestive heart failure, weakness in the left ventricle leads to ________.
edema of the tissues
Symptoms of CHF include
edema, increase blood pressure, shortness of breath, easy fatigue, dizziness, difficulty in walking short distances, compromised renal function
Patients who have had severed or repeated myocardial infarctions are at high risk for ________
congestive heart failure
B-type natriuretic peptide is a specific marker of ________
edema due to heart failure
BNP increases the _______ of the kidney to compensate for _________.
urine output, fluid accumulation associated with CHF.
Ischemia modified albumin
when in contact with ischemic tissue, albumin is altered, decreasing its ability to bind certain metals (esp. cobalt)
Separation techniques depend on differential ________.
physical characteristics
Common separation techniques in the clinical laboratory include _____ and ______.
electrophoresis, chromatography
Separation of charged particles during electrophoresis occurs because _________.
different molecules move at different rates
In electrophoresis, if the pH of the buffer is more basic than the pI, the protein carries a net _____ charge and will migrate to the ______.
negative, anode (positive pole)
Negatively charged molecules will move toward the _______ charged electrode known as the _____.
positively, anode
In addition to the electrical potential and the charge of the molecule, what forces can affect the movement of molecules in electrophoresis?
Friction due to shape (symmetry) and size
How is the voltage in the electrophoretic system chosen?
to minimize heat and buffer evaporation while maximizing resolution
The buffer in an electrophoretic system moves in the _____ direction to the flow of negatively charged sample molecules
Large highly charged proteins may migrate towards the like-charged electrode because they absorb OH ions from the buffer
Velocity of migration of molecules in electrophoresis is controlled by _________.
the net charge of the particle, size and shape of the particle, strength of the electric field, chemical and physical properties of the supporting medium and electrophoretic temperature.
Hepatic cirrhosis shows what patten on protein electrophoresis?
beta-gamma bridging and decreased albumin peak
Alpha-1-antitrypsin deficiency may cause what conditions?
emphysema, hepatic cirrhosis
A hemolyzed sample will cause what electrophoretic pattern?
Free hemoglobin peak between alpha-2 and beta or
Hemoglobin-haptoglobin complex peak in the alpha-2 region
(T/F) Significant protein is normally found in the urine
False, protein in urine is usually in negligible amounts
Elevated urine protein is an early indicator of ______.
renal impairment
What are Bence Jones proteins? They are present in what disorder?
Ig light chains, multiple myeloma
What is the proper sample for measurement of urine protein?
24 hour urine collection
What pattern will be seen in CSF electrophoresis in multiple sclerosis?
oligoclonal banding of gamma proteins
Major lipids
fatty acids, triglyceride, cholesterol, cholesteryl esters, phospholipids, bile acids
Cholesterol is slightly polar due to the ______
free OH group at C3
Cholesteryl ester is esterified at the _______
C3-OH group
Chylomicrons are _____ triglyceride and ______ cholesterol.
84%, 7%
VLDL is _____ triglyceride and ______ cholesterol
44-60%, 16-22%
IDL is ______ triglyceride and _____ cholesterol
23%, 29%
LDL is _______ triglyceride and ______ cholesterol
11%, 62%
HDL is _______ triglyceride and _______ cholesterol
3%, 19%
IDL and VLDL migrate near the ____ region in electrophoresis
LDL is readily taken up via LDL receptors in ______ and ______ cells.
liver, peripheral
plasma protein collects triglycerides from VLDL or LDL and exchanges them for cholesteryl esters from HDL, and vice versa.
Insulin, estrogen and thyroxine have what type of relationship with total cholesterol level?
Hypoalphalipoproteinemia is associated with increased risk of ____ due to _____.
CHD, build-up and blockage of blood vessels from excess LDL
Hyperbetalipoproteinemia results in lack of _______ because of poor ______. This leads to _______.
LDL uptake in steroid generating tissue, receptor specificity, deposition of cholesterol esters in tissues
Triglyceride analysis reactions
Detergent reagent breaks up lipoprotein particles into
their parts, releasing triglycerides into the solution

triglycerides + H2O + lipase yields fatty acids + glycerol

glycerol + ATP(Mg+2) + glycerol kinase yields glycerol-1-phosphate +ADP
glycerol-1-phosphate + O2 + glycerol phosphate oxidase yields DHAP + H2O2

H2O2 + 4-AAP + dye-precursor + peroxidase yields H2O + quinonimine dye (colored)
Potential problems with triglyceride analysis
free glycerol in the sample, standards are water soluble but triglyceride is water-insoluble (lipase and detergents must work), average molecular weight assumption, redox contaminants
Total cholesterol analysis reactions
detergent reagent breaks up lipoprotein particles into their parts, releasing cholesterol and cholesterol esters into the solution

cholesterol-ester + H2O + cholesterol esterase yields cholesterol + fatty acids

cholesterol + O2 + cholesterol oxidase yields cholestenone + H2O2

2H2O2 + reduced dye + peroxidase yields 4H2O + oxidized dye (colored)
Problems in total cholesterol analysis
interference from redox agents
Define enzymes
organic molecules that accelerate biochemical reactions
Enzymes act as ______ and emerge from reactions ______.
catalysts, unchanged
Why does the clinical laboratory usually measure enzymes?
To identify or monitor presence and amount of damaged tissue
AST conducts what reaction?
Transamination on aspartate
Most transaminases require what cofactor?
pyridoxal phosphate (a derivative of B6)
Most oxidases use what as a cofactor?
Creatine kinase performs what reaction?
Phosphorylation of creatine
Amylase conducts what reaction?
hydrolysis of starch (amylose)
Alkaline phosphatase conducts what reaction?
Removal of phosphate at alkaline pH
Enzymes ____ the rate of reaction but do not change the ______.
increase, equilibrium constant
Enzymes work by _____ the activation energy of the reaction. This happens because enzymes form _____ with the substrate.
decreasing, temporary intermediate bonds
Enzymes reduce the ______ needed to activate reactions
free energy
Define zero-order kinetics
Substrate concentration is high enough to saturate all enzyme present, reaction velocity is at max, rate is dependent only on enzyme concentration
Michaelis-Menten equation
V = Vmax[S] / (Km = [S])
Lineweaver-Burk equation
1/V = Km/Vmax[S] + 1/Vmax
Y intercept of Lineweaver-Burk plot
X-intercept of Lineweaver-Burk plot
Enzyme activity is extremely sensitive to its ______.
Measurement Reaction for CK (from creatine)
Creatine + ATP + CK ↔ Creatine phosphate + ADP

From ADP: (optimal pH = 9.0)
ADP + phophoenolpyruvate + PK ↔ pyruvate + ATP

Pyruvate + NADH + H+ + LD ↔ Lactate + NAD+
Measurement reaction for CK (from creatine phosphate)
(faster, optimal pH = 6.8)

Creatine phosphate + ADP + CK ↔ Creatine + ATP

ATP + Glucose + HK↔ Glucose- 6-phosphate + ADP

Glucose- 6-phosphate + NADP+ + G6PD ↔ 6-Phosphogluconate + NADPH + H+
Sources of error for CK analysis
hemolysis, exercise
Measurement reaction of LD
Lactate + NAD+ + LD ↔ Pyruvate + NADH + H+
Sources of error in measuring LD
hemolysis, refrigeration
AST reference range
15-30 U/L
Measurement reaction of AST
2-oxoglutarate + L-aspartate + AST ↔ L-glutamate + oxaloacetate

Oxaloacetate + NADH + H+ + MD ↔ NAD+ + L-Malate
At what wavelength does NADH/NADPH have peak absorbance?
340 nm
AST must use ______ serum.
ALT reference range
6-37 U/L
Increased levels of ALT are seen in what type of disorder?
Measurement reactions for ALT
alanine + alpha-ketoglutarate + ALT ↔ pyruvate + glutamate

pyruvate + NADH + H+ + LD ↔ lactate + NAD+
4 major isoenzymes of ALP. These enzymes differ in _____ stability.
bone, liver, placenta, intestine, heat
Phenylalanine inhibits ____ and ____ isoenzymes of ALP more than ______ and ______.
intestinal, placental, bone, liver
Measurement reactions for ALP
p-Nitropphenyl + ALP ↔ p-Nitrophenol + Phosphate ion

Increase in Abs. of p-nitrophenol is measured @ 405nm
Sources of error for ALP measurement
high fat, left at room temp or refrigerated
ACP is measured by what reaction?
p-nitrophenol reaction (pH = 5)
What are potential sources of error for ACP measurement?
hemolysis, sample left at room temperature (loss of CO2 resulting in pH change)
Reference range of GGT
up to 45 U/L
In addition to alcohol abuse, what other conditions result in increased GGT?
diabetes, MI, pancreatitis
Measurement reactions for GGT
gamma-glutamyl-p-nitroanilide + glycylglycine + GGT yields p-nitroaniline (colored dye) + gamma-glutamylglycylglycine
Tissue sources of amylase
salivary glands and pancreas
Sources of error in amylase measurement
high triglyceride, EDTA or citrate anticoagulant
Lipase is specific for diagnosis of _____.
acute pancreatitis
Reference range for lipase
10-200 U/L
Measurement reaction for lipase
triglycerides + lipase yields fatty acids + glycerol

glycerol + ATP(Mg+2) + glycerol kinase yields glycerol-1-phosphate + ADP

glycerol-1-phosphate + O2 + glycerol oxidase yields DHAP + H2O2

H2O2 + 4-AAP + dye-precursor yields H2O + quinonimine dye (colored)
Source of error in cholinesterase measurement
hemolysis (RBCs contain acetylcholinesterase)
In the body, iron is utilized in what 3 types of molecules?
enzymes, hemoglobin, myoglobin
As iron decreases, hepcidin synthesis ______. This results in release of iron from the _____ and _______ absorption in the duodenum.
decreases, spleen, increased
What test is the gold standard for iron assessment?
bone marrow examination
The serum iron assessment is sensitive to ________
mild iron deficiency
Transferrin saturation
The ratio of serum iron or iron-binding capacity

Serum iron/TIBC * 100
Which assessment is the most accurate indicator of iron supply to bone marrow?
Transferrin saturation
The serum transferrin receptor assay determines the cells' ______. It becomes _______ in iron deficiency.
need for iron, elevated
The best diagnostic test for iron deficiency is _______ as it measures the _______ in the body.
serum ferritin, iron stores
R/F ratio
sTfr/serum ferritin

used to provide estimate of iron stores
Iron levels can become transiently increased by iron ingestion so samples should be fasting. (T/F)
True. Additionally, iron has a diurnal variation so morning samples are best.
Colorimetric iron measurement reactions
Fe3+:Transferrin + acid yields Fe3+ + apotransferrin

Fe3+ + Reducing Agents yields Fe2+

Fe2+ + Complexing chromogen yields Colored complex
TIBC measurement
Saturate all binding sites with excess Fe+3
Remove excess unbound iron
Measure protein-bound iron (per iron method)
Various methods are used to remove the excess iron
TIBC - Serum iron
Oral contraceptives can increase serum ____ levels
UIBC measurement
Adds a fixed amount (in excess) Fe+3 at a neutral pH to saturate iron binding sites

The uptake of iron by the unoccupied serum iron-binding sites is measured by a serum iron method as a decrease in free iron.
Ferritin may be measured by ______.
Transferrin may be directly measured by _______.
immunological methods
Serum iron reference range
50-160 micrograms/dL
TIBC reference range
250-410 micrograms/dL
Laboratory results for iron deficiency anemia
decreased serum iron, increased TIBC, decreased % saturation, decreased ferritin
iron laboratory results for hemolytic anemia
increased iron, decreased to normal TIBC, increased percent saturation, increased ferritin
iron laboratory results for hemochromatosis
increased serum iron, normal to decreased TIB, increased percent saturation, increased ferritin
iron laboratory results for lead poisoning
decreased serum iron, normal TIBC, normal to increased % saturation, normal to increased ferritin
What is the normal blood lead level for children?
<10 mcg/dL
The free erythrocyte protoporphyrin assay is sensitive for low lead levels (T/F)
False, this test is not sensitive below 35 mcg/dL
Is the zinc protoporphyrin test specific for lead poisoning?
No, this test is also sensitive for iron deficiency and anemia of chronic disease
What enzymes of the heme synthesis pathway are blocked by lead poisoning?
ALA dehydratase, coproporphyrinogen oxidase, ferrochelatase
What treatment is curative for congenital erythropoietic porphyria?
bone marrow transplant
Define porphyrin
cyclic compound formed by methylene linkage of 4 pyrrole rings
Uro and coproporphyrinogens are soluble in _______.
protoporphyrin is soluble in ______.
Both porphyrinuria and porphyrinemia are (primary or secondary) conditions.
Categories of porphyrias
hepatic, erythropoietic
cutaneous, acute
Acute intermittent porphyria
hereditary defect of hepatic porphobilinogen deaminase, increased delta-ALA in urine, increased porphobilinogen in urine
Congenital erythropoietic porphyria
Gunther's disease, deficiency in uroporphyrinogen III cosynthase, increased ALA, uroporphyrinogen and coproporphyrinogen
Porphyria cutanea tarda
Most common porphyria, deficiency of uroporphyrinogen carboxylase, hepatic, increased uroporphyrin in urine, normal ALA and PBG
Watson-Schwatz test
Tests for porphobilinogen

PBG + Ehrlich’s gives red color

Must do extractions to prevent interference
Porphyrin test
Add amyl alcohol, ethel ether and glacial acetic acid to urine

Shake, allow to separate

Upper, organic layer will fluoresce if porphyrins are present
Reference range for free or zinc protoporphyrin
20 – 80 μg/dL
Serum level of LD peaks at _____ hours and returns to normal ____ to ____ days following AMI.
12, 7-14
Troponin levels return to normal _____ days after MI.
What compounds have been shown to help reduce homocysteine levels in the blood?
B vitamins, folic acid
In congestive heart failure, _____ slows, allowing _______ to accumulate in tissues.
circulation, water/waste
In patients with congestive heart failure, BNP serum levels are usually greater than _______.
100 pg/mL