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Clinical Chemistry Flashcards
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Clinical Chemistry Flashcards
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CC PREMID.pdf Flashcards
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1
Question
What are the two parts of meaningful quantitative results in laboratory results?
Answer
The numerical value and a label identifying the units (e.g., mass, length, time, volume, physical quantity, or dimension).
2
Question
What is the significance of SI Units (Système International d'Units)?
Answer
SI Units provide a global standard for describing physical quantities and were adopted internationally in 1960.
3
Question
What are the seven basic units in the SI system?
Answer
Length (meter), mass (kilogram), time (second), electric current (ampere), thermodynamic temperature (kelvin), amount of substance (mole), and luminous intensity (candela).
4
Question
What is an example of an SI derived unit?
Answer
Velocity (meters per second, m/s).
5
Question
What are some examples of non-SI units?
Answer
Hour, minute, day, gram, and liter.
6
Question
What is a primary standard?
Answer
A primary standard is a highly purified chemical (100.00% purity) with an exact known concentration.
7
Question
Why are NIST certified standard reference materials (SRMs) used in clinical chemistry?
Answer
Because biological constituents can't meet the strict criteria of traditional primary standards, SRMs are used to ensure calibration accuracy and are considered traceable to NIST.
8
Question
What is a secondary standard?
Answer
A secondary standard has lower purity and is measured by comparison with a primary standard; however, true secondary standards don't exist in clinical chemistry due to the lack of primary physiological standards.
9
Question
What are the types of reagent grade water?
Answer
Type I (highest purity), Type II (suitable for most analytic needs), Type III (acceptable for washing glassware but not for analytical use).
10
Question
What storage considerations should be taken for reagent grade water?
Answer
Reagent grade water, especially Clinical Laboratory Reagent Water (CLRW), should be stored carefully to prevent changes in water quality and minimize chemical and bacterial contamination.
11
Question
What is the purpose of quality testing parameters for reagent grade water?
Answer
To measure water quality through resistance (conductivity), resistivity, pH, and the presence of impurities.
12
Question
What does the mnemonic LEO (Lose Electrons Oxidized) and GER (Gain Electrons Reduced) help recall?
Answer
It helps recall redox reactions.
13
Question
What is the definition of a buffer in chemistry?
Answer
Buffers are weak acids or bases along with their related salts that help minimize changes in hydrogen ion concentration by dissociating in a controlled way.
14
Question
How is pH mathematically expressed?
Answer
pH is expressed as the negative logarithm of the hydrogen ion concentration in a solution, where pH = -log[H].
15
Question
What is the pH scale range and what does it indicate?
Answer
The pH scale ranges from 0 to 14; lower pH values indicate more acidic conditions and higher pH values indicate more basic conditions.
16
Question
What are Erlenmeyer flasks used for?
Answer
General use with a wide base and narrow neck; not for exact measurements.
17
Question
What is the main use of a Griffin beaker?
Answer
Flat-bottomed containers with wide mouths used for holding liquids in varying volumes, not for precision.
18
Question
What are graduated cylinders used for?
Answer
Cylindrical vessels with calibration marks used for measuring liquid volumes, but less accurate than volumetric labware.
19
Question
What are the general types of pipets?
Answer
They are used to transfer liquids and classified as TC (to contain) or TD (to deliver).
20
Question
What distinguishes a Mohr pipet?
Answer
Mohr pipets are self-draining but not graduated to the tip.
21
Question
What is the function of a micropipet?
Answer
It holds less than 1 mL for very small liquid transfers.
22
Question
What is the purpose of transfer pipets?
Answer
Transfer pipets are designed to dispense one fixed volume.
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1
Question
What are the varying pore sizes of filter papers used for in clinical chemistry?
Answer
Different filter papers have varying pore sizes; selection depends on separation needs and flow rates. Not suitable for strong acids or bases.
2
Question
Describe the process of using filter paper in clinical chemistry.
Answer
The filter paper is placed in a funnel. The solution drains through the paper into a receiving vessel. The liquid that passes through is termed the filtrate.
3
Question
What is the purpose of dialysis in clinical chemistry?
Answer
Dialysis separates macromolecules from solvents or smaller substances.
4
Question
What historical device popularized dialysis in the 1970s?
Answer
Dialysis gained popularity with the Technicon AutoAnalyzer in the 1970s.
5
Question
How does the mechanism of dialysis function?
Answer
A solution is placed in a bag or on one side of a semipermeable membrane. Larger molecules are retained while smaller molecules and solvents diffuse out.
6
Question
What is the efficiency of the dialysis process?
Answer
The process is slow and manual dialysis is largely replaced by gel-filled columns in most analytical procedures.
7
Question
Define significant figures (sig figs) in laboratory mathematics.
Answer
Significant figures or sig figs are the minimum number of digits required to accurately express a value in scientific notation without losing precision.
8
Question
Provide an example of significant figures.
Answer
8142 has four significant figures.
9
Question
How is normality (N) defined in clinical chemistry?
Answer
Normality N is expressed as equivalent weights per liter (Eq/L) or milliequivalents per milliliter (mmol/mL).
10
Question
How is equivalent weight calculated?
Answer
Equivalent weight is calculated as gram molecular weight (gmw) divided by valence (V).
11
Question
What is a key point regarding equivalent weight?
Answer
An equivalent weight of one substance is equal to the equivalent weight of any other chemical, facilitating comparisons across different substances.
12
Question
Define specific gravity in clinical chemistry.
Answer
Specific gravity is the ratio of the density of a material compared to the density of pure water at a given temperature.
13
Question
How is density measured?
Answer
Density is expressed as mass per unit volume, typically in grams per milliliter.
14
Question
In what application is specific gravity commonly used?
Answer
Specific gravity is commonly used for very concentrated materials such as commercial acids (e.g., sulfuric and hydrochloric acids).
15
Question
What are the elements involved in concentration calculation?
Answer
Actual concentration = Specific gravity x Assay or percent purity expressed as a decimal stated on the container label.
16
Question
What does spectrophotometry measure?
Answer
Spectrophotometry measures electromagnetic radiation to determine the concentration of atoms or molecules through absorption or emission of radiant energy.
17
Question
What do photometric instruments measure?
Answer
Photometric instruments measure light intensity without considering wavelength and use filters, prisms, or gratings to isolate a narrow range of incident wavelengths.
18
Question
How is electromagnetic radiation described?
Answer
Electromagnetic radiation is described as photons traveling in waves.
19
Question
What is Planck's formula?
Answer
Planck's formula is E = hν, where E is energy, h is Planck's constant (6.626 x 10^-34 erg·sec), and ν is frequency.
20
Question
What is the relationship between energy and wavelength in electromagnetic radiation?
Answer
Energy is inversely proportional to wavelength.
21
Question
What is the wavelength range of visible light?
Answer
Visible light ranges from violet (400 nm) to red (700 nm).
22
Question
What do double beam spectrophotometers do?
Answer
Double beam spectrophotometers automatically correct for sample and reference absorbance, making them useful for measuring absorption spectra.
23
Question
What modern innovations have replaced double beam instruments?
Answer
Computerized spectrophotometers with continuous zeroing systems have largely replaced double beam instruments, offering more convenience and accuracy in measurement.
24
Question
What does atomic absorption spectrophotometry (AAS) measure?
Answer
AAS measures concentration by detecting the absorption of electromagnetic radiation by atoms, not molecules.
25
Question
What is the usual light source in atomic absorption spectrophotometry?
Answer
The usual light source in AAS is a hollow cathode lamp composed of a cathode made of the metal being measured, an anode, and an inert gas (e.g., helium or argon).
26
Question
What occurs when voltage is applied to the hollow cathode lamp in AAS?
Answer
When voltage is applied, metal atoms are knocked off, become excited, and emit light characteristic of the metal.
27
Question
What is required for sample preparation in atomic absorption spectrophotometry?
Answer
The sample must contain the reduced metal in the atomic vaporized state, often done using a flame sample cell to break chemical bonds and form free atoms.
28
Question
What is the common device used for sample introduction in AAS?
Answer
The premix long path burner is commonly used for sample introduction, aspirating the sample as a fine spray and mixing it with air.
29
Question
What does turbidimetry measure?
Answer
Turbidimetry measures the concentration of particulate matter in a sample using a spectrophotometer, where the amount of light blocked depends on concentration and particle size.
30
Question
What is critical for handling samples in turbidimetry?
Answer
Handling of the sample is critical to prevent particles from aggregating and settling.
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1
Question
What are the most common types of pumps used in clinical chemistry?
Answer
Mechanical reciprocating pumps are the most common, allowing for constant flow.
2
Question
What is the role of stationary phases in chromatography?
Answer
Columns packed with stationary phases, such as silica gel, can operate at ambient or elevated temperatures.
3
Question
What is the function of loop injectors in sample introduction?
Answer
Loop injectors allow for precise and reproducible sample introduction.
4
Question
What is the purpose of detectors in chromatography?
Answer
Detectors monitor the eluate, producing signals proportional to concentration, commonly using UV spectrophotometers.
5
Question
What are some other types of detectors used in chromatography?
Answer
Other detectors include fluorescence and amperometric detectors.
6
Question
What is a chromatogram?
Answer
A chromatogram is created by recording detector signals against time, which helps identify compounds based on retention time and peak area.
7
Question
What is isocratic elution in chromatography?
Answer
Isocratic elution maintains a constant mobile phase composition throughout the separation.
8
Question
What is gradient elution in chromatography?
Answer
Gradient elution varies the mobile phase composition to improve separation of compounds with differing affinities for the stationary phase.
9
Question
What are the applications of chromatography?
Answer
Chromatography is used for separating a wide range of analytes, including drugs and biological samples, allowing for direct analysis without volatilization.
10
Question
What is gas chromatography (GC)?
Answer
Gas chromatography separates volatile compounds or those that can be made volatile.
11
Question
What is the function of Thermal Conductivity (TC) detectors?
Answer
TC detectors measure changes in electrical resistance due to temperature differences caused by the sample.
12
Question
How do Flame Ionization Detectors (FID) work?
Answer
FID detectors are more sensitive than TC detectors; the column effluent is burned in a flame creating ions that produce a current proportional to the concentration of the sample.
13
Question
What is the purpose of mass spectrometry (MS)?
Answer
MS is used for the definitive identification of samples eluting from chromatographic techniques like GC and HPLC.
14
Question
What is the significance of combining GCMS and LCMS?
Answer
The combination of GCMS and LCMS offers powerful analytic capabilities with broad clinical applications.
15
Question
What is the process overview of mass spectrometry?
Answer
Volatilization (conversion to gas), Ionization (creation of charged molecular ions and fragments), Separation (based on mass to charge ratio), Detection.
16
Question
What is the primary energy source for the brain, erythrocytes, and retinal cells in humans?
Answer
Carbohydrates are the primary energy source, stored mainly as glycogen in the liver and muscles.
17
Question
What are some disease states related to carbohydrates?
Answer
Hyperglycemia and hypoglycemia.
18
Question
What is the general formula for carbohydrates?
Answer
CxHOy, containing carbonyl (CO) and hydroxyl (OH) functional groups.
19
Question
How are carbohydrates classified?
Answer
Based on size, location of the carbonyl group, number of sugar units, and stereochemistry.
20
Question
What are examples of monosaccharides?
Answer
Simple sugars such as glucose and fructose.
21
Question
What are disaccharides?
Answer
Two monosaccharides linked together, such as maltose and sucrose.
22
Question
What are oligosaccharides?
Answer
Carbohydrates containing 2 to 10 sugar units.
23
Question
What are polysaccharides?
Answer
Many monosaccharide units linked together, such as starch and glycogen.
24
Question
What are reducing substances in carbohydrates?
Answer
Carbohydrates with aldehyde or ketone groups that can reduce other compounds, examples include glucose, maltose, and lactose.
25
Question
What is hyperglycemia?
Answer
Defined as an elevated level of glucose in the plasma.
26
Question
What is the role of insulin in glucose metabolism?
Answer
Insulin enhances cellular uptake of glucose in the liver, muscle, and adipose tissue, and alters glucose metabolic pathways.
27
Question
What is Diabetes Mellitus?
Answer
A group of metabolic disorders characterized by chronic hyperglycemia stemming from defects in insulin secretion, insulin action, or both.
28
Question
What are the key categories of diabetes as classified by the International Expert Committee?
Answer
Type 1 Diabetes, Type 2 Diabetes, Other Specific Types of Diabetes, and Gestational Diabetes Mellitus.
29
Question
What characterizes Type 1 Diabetes Mellitus?
Answer
Results from autoimmune destruction of pancreatic cells leading to an absolute deficiency of insulin, often with sudden onset in childhood or adolescence.
30
Question
What is the Hyperosmolar Nonketotic State related to Type 2 Diabetes?
Answer
Marked by overproduction of glucose and a failure to excrete it in urine, often with severe dehydration and high glucose levels.
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1
Question
What is the revised recommendation for screening nondiabetic pregnant women for GDM?
Answer
All nondiabetic pregnant women should be screened for GDM at 24 to 28 weeks of gestation using a 2-hour OGTT with a 75 g glucose load.
2
Question
What are the glucose measurement criteria for diagnosing GDM?
Answer
Fasting plasma glucose: 92 mg/dL (5.1 mmol/L), 1-hour plasma glucose: 180 mg/dL (10.0 mmol/L), 2-hour plasma glucose: 153 mg/dL (8.5 mmol/L). Any one of these criteria met is diagnostic for GDM.
3
Question
When should GDM testing be performed?
Answer
Testing should be performed in the morning after an overnight fast of at least 8 hours.
4
Question
What is hypoglycemia characterized by?
Answer
Hypoglycemia is characterized by decreased plasma glucose levels.
5
Question
What are some causes of hypoglycemia?
Answer
Hypoglycemia can have various causes ranging from transient and minor to life-threatening conditions.
6
Question
What is the critical plasma glucose concentration for the release of glucagon and other glycemic factors?
Answer
The critical plasma glucose concentration for the release of glucagon and other glycemic factors is between 65 and 70 mg/dL (3.6 to 3.9 mmol/L).
7
Question
At what glucose levels do symptoms of hypoglycemia typically appear?
Answer
Symptoms of hypoglycemia typically appear when glucose levels drop to around 50 to 55 mg/dL (2.8 to 3.1 mmol/L).
8
Question
What is the hormonal response when plasma glucose levels fall?
Answer
When plasma glucose levels fall, glucagon is released from the pancreas to raise glucose levels, while epinephrine from the adrenal glands increases glucose metabolism and inhibits insulin release. Cortisol and growth hormone also contribute by increasing glucose metabolism.
9
Question
What are some warning signs of hypoglycemia related to the central nervous system?
Answer
Increased hunger, sweating, nausea, dizziness, nervousness, shaking, blurred speech and vision, and mental confusion.
10
Question
What is the D-glucose enzymatic method used for?
Answer
The D-glucose enzymatic method is specific for converting D-glucose to gluconic acid and producing hydrogen peroxide.
11
Question
What are some interferences in the D-glucose enzymatic method?
Answer
The D-glucose enzymatic method is subject to interference from substances like uric acid and ascorbic acid.
12
Question
What is the Hexokinase Method?
Answer
The Hexokinase Method is a more accurate and specific method where glucose is converted to glucose 6-phosphate, which is then measured by the production of NADPH.
13
Question
What makes the Hexokinase Method preferred?
Answer
The Hexokinase Method is not affected by ascorbic acid or uric acid, making it a preferred reference method.
14
Question
How often does the American Diabetes Association recommend individuals with Type 1 Diabetes monitor their blood glucose levels?
Answer
Individuals with Type 1 Diabetes should monitor their blood glucose levels 3 to 4 times daily.
15
Question
How frequently should individuals with Type 2 Diabetes monitor their blood glucose levels?
Answer
Frequency of blood glucose monitoring in individuals with Type 2 Diabetes may vary based on individual needs.
16
Question
What is the purpose of glucose tolerance testing (GTT)?
Answer
The 2-hour postprandial test involves administering a standardized 75 g glucose load and measuring plasma glucose levels.
17
Question
What does the enzymatic method detect related to 3-hydroxybutyrate?
Answer
The enzymatic method uses the enzyme 3-hydroxybutyrate dehydrogenase to detect either 3-beta hydroxybutyric acid or acetoacetic acid depending on pH.
18
Question
What is microalbuminuria and its significance in diabetic nephropathy?
Answer
Microalbuminuria is defined as persistent albuminuria in two out of three urine collections with 30 to 300 mg/24h (20 to 200 µg/min). It indicates early detection of nephropathy which can help delay progression through aggressive glycemic control.
19
Question
What is the definition of macroalbuminuria?
Answer
Macroalbuminuria is defined by an albumin creatinine ratio of 300 mg/24h (200 µg/min) or 300 µg/mg creatinine.
20
Question
What is the preferred screening method for microalbuminuria?
Answer
The preferred method is a random spot collection for the albumin creatinine ratio.
21
Question
What are chylomicrons responsible for?
Answer
Chylomicrons transport dietary triglycerides from the intestines to the liver.
22
Question
What do very low density lipoproteins (VLDLs) do?
Answer
VLDLs distribute triglycerides to peripheral tissues for energy or storage.
23
Question
What is the role of low density lipoproteins (LDLs)?
Answer
LDLs deliver cholesterol to cells after offloading triglycerides.
24
Question
What is the function of high density lipoproteins (HDLs)?
Answer
HDLs collect excess cholesterol from tissues and transport it back to the liver for disposal.
25
Question
What is the importance of lipids in the body?
Answer
Lipids, primarily triglycerides, phospholipids, and cholesterol, serve as energy sources, structural components of cell membranes, and precursors for hormones.
26
Question
What is a significant health concern associated with elevated blood lipid levels?
Answer
Elevated blood lipid levels are associated with coronary heart disease (CHD), especially in populations with high fat intake.
27
Question
What are fatty acids composed of?
Answer
Fatty acids are linear chains of carbon and hydrogen ending with a carboxyl group (COOH). They exist mainly as part of triglycerides or phospholipids.
28
Question
How are intermediate density lipoproteins (IDLs) classified?
Answer
IDLs are transitional particles between VLDL and LDL, generally do not accumulate in normal plasma but can be elevated in type III hyperlipoproteinemia.
29
Question
What are some characteristics of LDLs?
Answer
LDLs are cholesterol-rich particles formed from VLDL lipolysis, primarily contain apo B-100, and infiltrate vessel walls contributing to atherosclerosis by macrophage uptake forming foam cells.
30
Question
What is lipoprotein(a) [Lp(a)]?
Answer
Lipoprotein(a) [Lp(a)] are LDL-like particles containing apo(a) linked to apo B-100, associated with increased risk of CHD and stroke, and competes with plasminogen affecting clotting processes.
CC PREMID.pdf Flashcards
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1
Question
What is Hyperlipoproteinemia?
Answer
A disorder characterized by elevated levels of lipoproteins in serum.
2
Question
What are Dyslipidemias?
Answer
Disorders that can be divided into Hyperlipoproteinemias, which are characterized by elevated lipoprotein levels, and Hypolipoproteinemias, which are characterized by decreased lipoprotein levels.
3
Question
What are the types of Hyperlipoproteinemias?
Answer
1. Hypercholesterolemia 2. Hypertriglyceridemia 3. Combined hyperlipidemia (elevations in both cholesterol and triglycerides).
4
Question
What is Hypercholesterolemia?
Answer
A condition characterized by elevated levels of cholesterol in the blood.
5
Question
What is Hypertriglyceridemia?
Answer
A condition characterized by elevated levels of triglycerides in the blood.
6
Question
What is Combined hyperlipidemia?
Answer
A condition characterized by elevations in both cholesterol and triglycerides.
7
Question
What are Hypolipoproteinemias?
Answer
Disorders characterized by decreased lipoprotein levels.
8
Question
How is Hypercholesterolemia associated with Heart Disease?
Answer
It is strongly linked to coronary heart disease (CHD).
9
Question
What is Familial Hypercholesterolemia (FH)?
Answer
A genetic disorder that results in high cholesterol levels.
10
Question
What are the characteristics of Homozygotes in Familial Hypercholesterolemia?
Answer
Rare, with total cholesterol that can exceed 800 mg/dL, leading to early heart attacks in teens.
11
Question
What are the characteristics of Heterozygotes in Familial Hypercholesterolemia?
Answer
More common, with total cholesterol ranging from 300 to 600 mg/dL, leading to symptoms typically appearing in their twenties to fifties.
12
Question
What are the symptoms of Hypercholesterolemia?
Answer
Tendinous and tuberous xanthomas, arcus.
13
Question
What is the mechanism behind Familial Hypercholesterolemia?
Answer
Defective LDL receptors lead to cholesterol accumulation.
14
Question
What are LDL Receptor Mutations?
Answer
Several classes (1-5) affecting receptor function and transport.