1.
The biuret reaction for the analysis of serum protein depends on the number of?
Correct Answer
C. Peptide bonds
Explanation
The biuret reaction is a chemical test used to detect the presence of peptide bonds in proteins. It involves the reaction of copper ions with the peptide bonds, resulting in a color change from blue to purple. Therefore, the number of peptide bonds present in a protein sample determines the intensity of the color change, making peptide bonds the key factor in the biuret reaction for the analysis of serum protein. Free amino acids, free carboxyl groups, and tyrosine residues are not directly involved in this reaction.
2.
Calcium concentration in the serum is regulated by?
Correct Answer
B. Parathyroid hormone
Explanation
Parathyroid hormone is responsible for regulating the concentration of calcium in the serum. This hormone is produced by the parathyroid glands, which are located in the neck. When the calcium levels in the blood are low, the parathyroid glands release parathyroid hormone, which stimulates the release of calcium from the bones and increases the absorption of calcium from the intestines. This helps to maintain the balance of calcium in the body and ensure that it is available for important functions such as muscle contraction and nerve transmission.
3.
In the liver, bilirubin is converted to:
Correct Answer
D. Bilirubin diglucuronide
Explanation
In the liver, bilirubin is converted to bilirubin diglucuronide. Bilirubin is a waste product that is formed when red blood cells break down. It is then transported to the liver where it undergoes a series of chemical reactions to become bilirubin diglucuronide. This conjugated form of bilirubin is then excreted into the bile and eventually eliminated from the body through the feces.
4.
The osmolality of a urine or serum specimen is measured by a change in the?
Correct Answer
A. Freezing point
Explanation
The osmolality of a urine or serum specimen is measured by a change in the freezing point. This is because the number of solute particles in a solution affects its freezing point. When solutes are present in a specimen, they lower the freezing point of the solution. By measuring the extent of this change in freezing point, the osmolality of the specimen can be determined.
5.
Which of the following steroids is an adrenal cortical hormone?
Correct Answer
B. Corticosterone
Explanation
Corticosterone is an adrenal cortical hormone. It is produced by the adrenal cortex and plays a role in regulating various physiological processes in the body, including metabolism, immune response, and stress response. It is classified as a glucocorticoid, which means it helps regulate glucose levels in the body. Corticosterone is also involved in the body's response to inflammation and helps suppress the immune system when necessary. Therefore, corticosterone is the correct answer as it is a steroid hormone produced by the adrenal cortex.
6.
Which two conditions can “physiologically” elevate serum alkaline phosphatase?
Correct Answer
C. Growth, third trimester of pregnancy
Explanation
During periods of growth and in the third trimester of pregnancy, the body undergoes physiological changes that can elevate serum alkaline phosphatase levels. This is because alkaline phosphatase is involved in bone formation and is released from growing bones and the placenta during pregnancy. Rickets and hyperparathyroidism can also elevate serum alkaline phosphatase, but they are not considered physiological conditions. Obstructive jaundice, viral hepatitis, and infectious mononucleosis can increase alkaline phosphatase levels, but they are not related to growth or pregnancy.
7.
During an elevation of adrenal function, a patient had plasma cortisol determination is the morning after awakening and in the evening. Laboratory results indicated that the morning value was higher than the evening concentration. This is indicative of?
Correct Answer
A. A normal finding
Explanation
The higher morning value of plasma cortisol compared to the evening concentration is a normal finding. This is because cortisol levels naturally fluctuate throughout the day, with the highest levels occurring in the morning and the lowest levels in the evening. This pattern is known as diurnal variation and is a normal physiological response. Therefore, the laboratory results indicating a higher morning value are within the expected range and do not suggest any abnormality or disease.
8.
In electrophoretic analysis, buffers?
Correct Answer
C. Act as a carrier for ions
Explanation
In electrophoretic analysis, buffers act as a carrier for ions. Buffers are used to maintain a constant pH in the electrophoresis system. They provide a medium for the movement of ions, allowing them to migrate through the gel or solution. This movement of ions is essential for the separation and analysis of molecules in electrophoresis. Buffers help to create an electric field and facilitate the movement of charged particles, such as proteins or DNA, towards the oppositely charged electrode.
9.
The T3 resin uptake test is a measure of?
Correct Answer
C. Binding capacity of thyroxine-binding globulin
Explanation
The T3 resin uptake test measures the binding capacity of thyroxine-binding globulin. This test is used to assess the levels of thyroxine-binding globulin in the blood, which is a protein that binds to thyroid hormones. By measuring the binding capacity of this protein, the test can provide information about the availability of thyroid hormones in the blood.
10.
Blood PCO2 may be measured by?
Correct Answer
B. Calculations of blood pH and total CO2 concentration
Explanation
Blood PCO2 can be measured by calculating the blood pH and total CO2 concentration. This is because the PCO2 value is indirectly related to the blood pH and total CO2 concentration. By measuring the blood pH and total CO2 concentration, the PCO2 level can be estimated using various equations and calculations. This method is commonly used in clinical settings to assess the acid-base balance and respiratory function of a patient.
11.
Which of the following serum constituents is unstable if a blood specimen is left standing at room temperature for 8 hours before processing?
Correct Answer
D. Glucose
Explanation
Glucose is the correct answer because it is a rapidly metabolized substance and can be broken down by enzymes present in the blood. When a blood specimen is left standing at room temperature for 8 hours, the metabolic activity in the blood continues, leading to a decrease in glucose levels. Therefore, glucose is unstable if left standing at room temperature for a prolonged period before processing.
12.
Total iron-binding capacity measures the serum iron transporting capacity of?
Correct Answer
C. Transferrin
Explanation
Total iron-binding capacity (TIBC) measures the serum iron transporting capacity. Transferrin is a protein in the blood that binds to iron and transports it throughout the body. TIBC is a measure of how much transferrin is available to bind with iron. Therefore, the correct answer is Transferrin.
13.
In a spectrophotometer, light of a specific wavelength can be isolated from white light with a(n)?
Correct Answer
B. Diffraction grating
Explanation
A diffraction grating is a device that can separate white light into its component wavelengths by causing the light to diffract. It consists of a large number of closely spaced parallel slits or lines, which act as sources of secondary waves. These secondary waves interfere with each other, resulting in constructive and destructive interference patterns. By adjusting the spacing between the slits or lines, a specific wavelength of light can be isolated and passed through the spectrophotometer. Therefore, a diffraction grating is used to isolate light of a specific wavelength from white light in a spectrophotometer.
14.
Absorbance (A) of a solution may be converted to percent transmittance (%T) using the formula?
Correct Answer
D. 2 - Log %T
15.
A condition in which erythrocyte protoporphyrin is increased is?
Correct Answer
B. Iron Deficiency anemia
Explanation
Iron deficiency anemia is a condition characterized by a decrease in the production of hemoglobin, which is essential for the formation of red blood cells. In this condition, the body compensates by increasing the production of erythrocyte protoporphyrin, a precursor molecule in the synthesis of hemoglobin. Therefore, an increased level of erythrocyte protoporphyrin is indicative of iron deficiency anemia.
16.
The formula for calculating serum osmolaliity that incorporates a correction for the water content of plasma is?
Correct Answer
C. 2 Na + Glucose/20 + (BUN/3)
Explanation
The correct answer is 2 Na + Glucose/20 + (BUN/3). This formula is used to calculate serum osmolality and incorporates a correction for the water content of plasma. The formula takes into account the concentrations of sodium (Na), glucose, and blood urea nitrogen (BUN) in the plasma. The correction for the water content of plasma is achieved by dividing the glucose concentration by 20 and the BUN concentration by 3. The formula then adds the product of 2 times the sodium concentration, the glucose concentration divided by 20, and the BUN concentration divided by 3.
17.
The first step to be taken when attempting to repair a piece of electronic equipment is?
Correct Answer
C. Turn the instrument off
Explanation
The first step to be taken when attempting to repair a piece of electronic equipment is to turn the instrument off. This is important for safety reasons as it eliminates the risk of electric shock. By turning off the instrument, you ensure that there is no power running through it, reducing the chances of accidents or further damage. It also allows you to work on the equipment without any interference from electrical currents.
18.
Most of the carbon dioxide present in the blood is in the form of?
Correct Answer
C. Bicarbonate ion
Explanation
The majority of carbon dioxide in the blood is transported in the form of bicarbonate ions. When carbon dioxide diffuses into red blood cells, it combines with water to form carbonic acid. Carbonic acid then dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are transported in the plasma, while the hydrogen ions bind to hemoglobin. This bicarbonate ion transport mechanism helps maintain the acid-base balance in the body.
19.
The statistical term for the average value is the?
Correct Answer
C. Mean
Explanation
The statistical term for the average value is the mean. The mean is calculated by summing up all the values in a dataset and dividing it by the total number of values. It is commonly used to represent the central tendency of a set of data and provides a measure of the typical value.
20.
An index of precision is statistically known as the?
Correct Answer
D. Coefficient of variation
Explanation
The coefficient of variation is a statistical measure that represents the index of precision. It is calculated by dividing the standard deviation by the mean and multiplying it by 100. The coefficient of variation is used to compare the variability of different datasets, especially when the means are different. Therefore, the coefficient of variation is the correct answer for this question.
21.
The most frequent value in a collection of data is statistically known as the?
Correct Answer
A. Mode
Explanation
The most frequent value in a collection of data is known as the mode. The mode is the value that appears the most number of times in the data set. It is a measure of central tendency and is used to describe the typical or most common value in the data. Unlike the mean and median, the mode does not consider the magnitude of the values, only their frequency of occurrence. Therefore, the mode is the correct answer in this case.
22.
The middle value of a data set is statistically known as the?
Correct Answer
B. Median
Explanation
The middle value of a data set is statistically known as the median. The median is calculated by arranging the data set in ascending order and finding the value that falls exactly in the middle. It is a measure of central tendency that is not affected by extreme values or outliers in the data. The median is useful when the data set has a skewed distribution or contains outliers.
23.
In a specimen collected for plasma glucose analysis, sodium floride?
Correct Answer
D. Inhibits glycolysis
Explanation
Sodium fluoride inhibits glycolysis. Glycolysis is the process by which glucose is broken down to produce energy in the form of ATP. Sodium fluoride acts as an inhibitor of the enzyme enolase, which is involved in the glycolysis pathway. By inhibiting enolase, sodium fluoride disrupts the glycolysis process, leading to a decrease in ATP production.
24.
The serum that contributes to most serum osmolality is?
Correct Answer
B. Sodium
Explanation
Sodium is the major cation in extracellular fluid and plays a crucial role in maintaining osmotic balance. It contributes significantly to serum osmolality, which is a measure of the concentration of solutes in the blood. Glucose, chloride, and urea also contribute to osmolality, but sodium has the greatest impact.
25.
Which family of steroid hormones is characterized by an unsaturated A ring?
Correct Answer
B. Estrogens
Explanation
Estrogens are a family of steroid hormones that are characterized by an unsaturated A ring. This means that the A ring of the estrogen molecule has one or more double bonds, which gives it a different structure compared to other steroid hormones such as progestins, androgens, and glucocorticoids. Estrogens play a crucial role in the development and regulation of female reproductive system and secondary sexual characteristics. They are primarily produced in the ovaries and also in smaller amounts in the adrenal glands and fat cells.
26.
Which of the following serum protein fractions is most likely to be elevated in patients with nephrotic syndrome?
Correct Answer
C. AlpHa-2 globulin and beta globulin
Explanation
Patients with nephrotic syndrome often have increased levels of alpha-2 globulin and beta globulin in their serum protein fractions. This is because nephrotic syndrome is characterized by increased permeability of the glomerular filtration barrier, leading to the loss of proteins in the urine. Alpha-2 globulin and beta globulin are larger proteins that are more likely to be lost in the urine compared to smaller proteins like alpha-1 globulin. Therefore, the levels of alpha-2 globulin and beta globulin are typically elevated in patients with nephrotic syndrome.
27.
The following lab results were obtained from arterial blood:
sodium 136 mEq/L
pH 7.32
Potassium 4.4 mEq/L
PCO2 79 mm Hg
Chloride 92 mEq/L
Bicarbonate 40 mEq/L
these results are compatible with?
Correct Answer
B. Respiratory acidosis
Explanation
The lab results show a low pH (7.32) and an elevated PCO2 (79 mm Hg), indicating respiratory acidosis. Respiratory acidosis occurs when there is inadequate removal of carbon dioxide (CO2) from the body, leading to an accumulation of CO2 in the blood. This can be caused by conditions such as hypoventilation or lung diseases that impair gas exchange. The other electrolyte levels (sodium, potassium, chloride, and bicarbonate) are within normal ranges and do not provide evidence for metabolic acidosis or alkalosis.
28.
Which of the following statements about fluorometry are true?
Correct Answer
A. A compound is said to fluoresce when it absorbs light at one wavelength and emits light at a second wave length
Explanation
Fluorometry is a technique that involves the measurement of fluorescence, which occurs when a compound absorbs light at one wavelength and emits light at a different wavelength. This statement accurately describes the concept of fluorescence. The other statements are not true. Detectors in fluorometers are typically placed at a 90-degree angle from the excitation source, not 180 degrees. Fluorometry is actually more sensitive than spectrophotometry because it can detect lower concentrations of compounds. Finally, complexing of components may still be necessary in fluorometry depending on the specific experiment or analysis being conducted.
29.
Two standard deviations is the acceptable limit of error in the chemistry laboratory. If you run the normal control 100 times, how many of the values wou;d be out of control due to random error?
Correct Answer
B. 5
Explanation
In a normal distribution, approximately 5% of the values fall outside of two standard deviations from the mean. Therefore, if the normal control is run 100 times, it can be expected that approximately 5 of the values would be out of control due to random error.
30.
Serum anion gap is increased in patients with?
Correct Answer
D. Lactic acidosis
Explanation
Lactic acidosis is a condition characterized by the accumulation of lactic acid in the body. This can occur due to various reasons such as impaired metabolism, tissue hypoxia, or liver dysfunction. An increased serum anion gap is commonly seen in lactic acidosis. The anion gap is a measure of the difference between the cations and anions in the serum and is used to evaluate the presence of unmeasured anions. In lactic acidosis, the accumulation of lactic acid leads to an increase in the anion gap. Therefore, the correct answer is lactic acidosis.
31.
The nanometer is used as a measure of?
Correct Answer
D. Wavelength of radiant energy
Explanation
The nanometer is used as a measure of wavelength of radiant energy. A nanometer is equal to one billionth of a meter and is commonly used to measure the length of electromagnetic waves, including visible light. It is particularly useful in determining the color of light as different colors have different wavelengths.
32.
A common cause of respiratory alkalosis is?
Correct Answer
D. Hyperventilation
Explanation
Hyperventilation is a common cause of respiratory alkalosis. When a person hyperventilates, they breathe rapidly and shallowly, leading to a decrease in carbon dioxide levels in the blood. This results in a shift towards alkalinity in the body's pH balance, causing respiratory alkalosis. Hyperventilation can be triggered by anxiety, panic attacks, or certain medical conditions.
33.
Major actions of angiotensin II include?
Correct Answer
B. Increased vasoconstriction
Explanation
Angiotensin II is a hormone that plays a key role in regulating blood pressure and fluid balance in the body. One of its major actions is increased vasoconstriction, which means it causes the blood vessels to constrict or narrow. This narrowing of blood vessels leads to an increase in blood pressure. Therefore, increased vasoconstriction is a significant effect of angiotensin II.
34.
The anion gap is useful for QC of laboratory results for?
Correct Answer
C. Sodium, potassium, chloride, and total CO2
Explanation
The anion gap is useful for quality control (QC) of laboratory results for sodium, potassium, chloride, and total CO2. The anion gap is calculated by subtracting the sum of the measured anions (chloride and total CO2) from the sum of the measured cations (sodium and potassium). It helps to ensure that the electrolyte levels are correctly measured and balanced in the body. By monitoring the anion gap, any discrepancies or errors in the laboratory results can be identified and corrected, thus improving the accuracy and reliability of the tests.
35.
Which of the following electrolytes is the chief plasma cation whose main function is maintaining osmotic pressure?
Correct Answer
D. Sodium
Explanation
Sodium is the chief plasma cation that plays a crucial role in maintaining osmotic pressure. Osmotic pressure is the force that keeps fluids balanced inside and outside of cells. Sodium helps regulate fluid balance by attracting and retaining water in the bloodstream. It also aids in nerve function, muscle contraction, and maintaining blood pressure. Calcium, potassium, and chloride are also important electrolytes, but they do not have the same primary function as sodium in maintaining osmotic pressure.
36.
What is the molarity of a solution that contains 18.7 g of KCI (MW=74.5) in 500 ml of water?
Correct Answer
B. 0.5
Explanation
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution in liters. In this case, we need to first convert the mass of KCI to moles by dividing it by the molar mass of KCI (74.5 g/mol). Then, we divide the number of moles by the volume of the solution in liters (500 ml = 0.5 L). Therefore, the molarity is 0.5 M.
37.
The buffering capacity of blood is maintained by a reversible exchange process between bicarbonate and?
Correct Answer
D. Chloride
Explanation
The buffering capacity of blood is maintained by a reversible exchange process between bicarbonate and chloride. Chloride ions play a crucial role in maintaining the acid-base balance in the body. When there is an excess of acid in the blood, bicarbonate ions combine with hydrogen ions to form carbonic acid, which then breaks down into water and carbon dioxide. In this process, chloride ions move out of the red blood cells to maintain electrical neutrality. Similarly, when there is an excess of base in the blood, chloride ions move into the red blood cells to maintain balance. Therefore, chloride is essential for the buffering capacity of blood.
38.
The different water content of erythrocytes and plasma makes true glucose concentrations in whole blood a function of the?
Correct Answer
A. Hematocrit
Explanation
The different water content of erythrocytes and plasma means that the concentration of glucose in whole blood is affected by the hematocrit. Hematocrit refers to the volume percentage of red blood cells in the blood, and since erythrocytes have a lower water content compared to plasma, the hematocrit will affect the true glucose concentrations in whole blood.
39.
Acidosis and alkalosis are best defined as fluctuations in blood pH and CO2 content due to changes in?
Correct Answer
C. Bicarbonate buffer
Explanation
Acidosis and alkalosis refer to imbalances in blood pH and CO2 content. The bicarbonate buffer system plays a crucial role in maintaining the pH balance in the blood. It consists of bicarbonate ions (HCO3-) and carbonic acid (H2CO3), which can either accept or donate hydrogen ions (H+). When there is an excess of acid in the blood, the bicarbonate ions act as a base and bind with the hydrogen ions, helping to neutralize the acidity. Conversely, when there is an excess of base in the blood, the carbonic acid can release hydrogen ions, helping to restore the pH balance. Therefore, changes in the bicarbonate buffer system can lead to fluctuations in blood pH and CO2 content, resulting in acidosis or alkalosis.
40.
Metabolic acidosis is described as a(n)?
Correct Answer
D. Decrease in CO2 content and PCO2 with a decreased pH
Explanation
Metabolic acidosis is a condition characterized by a decrease in the content of carbon dioxide (CO2) and partial pressure of carbon dioxide (PCO2) in the body, leading to a decreased pH. This means that there is an imbalance in the body's acid-base levels, resulting in an acidic environment. The decrease in CO2 and PCO2 levels indicates that the body is unable to properly eliminate carbon dioxide, leading to an accumulation of acids and a decrease in pH.
41.
The normal range for the pH of arterial blood measured at 37 degrees Celsius is?
Correct Answer
C. 7.35-7.45
Explanation
The normal range for the pH of arterial blood measured at 37 degrees Celsius is 7.35-7.45. This range is considered normal because it reflects the optimal pH level for the body's metabolic processes to function properly. Any deviation from this range can indicate an imbalance in the body's acid-base balance, which may be a sign of an underlying health condition.
42.
Hydrogen ion concentration (pH) in blood is usually determined by means of which of the following electrodes?
Correct Answer
B. Glass
Explanation
Glass electrodes are commonly used to measure the pH of a solution, including the hydrogen ion concentration in blood. These electrodes work by using a thin glass membrane that is sensitive to changes in pH. The glass membrane allows for the exchange of hydrogen ions between the sample and the internal reference solution within the electrode. As the pH of the sample changes, a potential difference is generated, which can be measured and used to determine the pH. Therefore, the glass electrode is the most suitable option for determining hydrogen ion concentration in blood.
43.
The conversion of glucose or other hexoses into lactate or pyruvate is called?
Correct Answer
D. Glycolysis
Explanation
Glycolysis is the correct answer because it is the process of converting glucose or other hexoses into lactate or pyruvate. During glycolysis, glucose is broken down into two molecules of pyruvate, which can then be further metabolized to produce energy. This process occurs in the cytoplasm of cells and is an important step in both aerobic and anaerobic respiration. Glycogenesis, glycogenolysis, and gluconeogenesis are all different processes involved in the regulation of glucose metabolism, but they are not specifically related to the conversion of glucose into lactate or pyruvate.
44.
A reciprocal relationship exists between?
Correct Answer
B. Calcium and pHospHorus
Explanation
Calcium and phosphorus have a reciprocal relationship because they both play crucial roles in maintaining strong and healthy bones. Calcium is necessary for bone formation, while phosphorus helps in the formation and repair of bones and teeth. They work together to regulate the levels of calcium and phosphorus in the body, ensuring proper bone mineralization and overall bone health. The balance between calcium and phosphorus is essential for optimal bone strength and function.
45.
Respiratory acidosis is described as a(n)?
Correct Answer
A. Increase in CO2 content and PCO2 with a decreased pH
Explanation
Respiratory acidosis is a condition characterized by an increase in carbon dioxide (CO2) content and partial pressure of carbon dioxide (PCO2) in the blood, leading to a decrease in pH. This occurs when the lungs are unable to effectively remove CO2 from the body, causing it to accumulate in the bloodstream. The increased CO2 levels result in the production of carbonic acid, which lowers the pH of the blood, leading to acidosis. Therefore, the correct answer is an increase in CO2 content and PCO2 with a decreased pH.
46.
Which of the following hemoglobins has glucose-6-phosphate on the amino-terminal valine of the beta chain?
Correct Answer
D. A1c
Explanation
A1c hemoglobin, also known as glycated hemoglobin, is formed when glucose in the blood binds to the amino-terminal valine of the beta chain of hemoglobin. This occurs when blood glucose levels are high over a prolonged period of time. A1c hemoglobin is commonly used as a marker for long-term glucose control in individuals with diabetes.
47.
The function of the major lipid components of the very low density lipoproteins (VLDL) is to transport?
Correct Answer
D. Endogenous triglycerides
Explanation
The major lipid components of very low density lipoproteins (VLDL) are primarily responsible for transporting endogenous triglycerides. VLDL is synthesized in the liver and carries triglycerides synthesized in the liver to peripheral tissues for energy storage. This process is important for regulating lipid metabolism and maintaining energy balance in the body.
48.
A hospitalized patient is experiencing increased neuromuscular irritability (tetany). Which of the following tests should be ordered immediately?
Correct Answer
A. Calcium
Explanation
A hospitalized patient experiencing increased neuromuscular irritability (tetany) should have their calcium levels tested immediately. Tetany is often caused by low levels of calcium in the blood, which can lead to muscle spasms and twitching. By ordering a calcium test, healthcare providers can determine if the patient's tetany is due to hypocalcemia and take appropriate measures to correct it. The other tests listed (phosphorus, BUN, and glucose) may be important in certain clinical situations, but they are not as directly related to the symptoms of tetany as calcium.
49.
Sixty to seventy-five percent of the plasma cholesterol is transported by?
Correct Answer
C. LDL
Explanation
LDL (low-density lipoprotein) is responsible for transporting 60 to 75% of the plasma cholesterol. LDL carries cholesterol from the liver to the cells throughout the body. High levels of LDL cholesterol are associated with an increased risk of heart disease.
50.
Measurement of total T4 by competitive protein binding or displacement is based on the specific binding properties of?
Correct Answer
C. Thyroxine-binding globulin
Explanation
The measurement of total T4 by competitive protein binding or displacement is based on the specific binding properties of thyroxine-binding globulin. Thyroxine-binding globulin is a protein in the blood that binds to thyroxine (T4) and carries it throughout the body. By measuring the amount of T4 that is bound to thyroxine-binding globulin, the total T4 level can be determined. This measurement is important in assessing thyroid function and diagnosing thyroid disorders.