MMSC 407 Exam 1 Questions With Complete Solutions
"out of control" Correct Answers errors can lead the WC
control to be out of the accepted +/- 2 standard deviation from
the mean range
absorbance assumptions Correct Answers to read absorbance 2
factors are assumed
-monochromatic light: it is assumed that only a single
wavelength of light is being used
-logarithmic relationship: as absorbance increases the %T (%
transmission of light) goes down logarithmically
absorbance Correct Answers a value that is CALCULATED
(not measured) based on %T to determine how much of the light
is absorbed
-%T is measured and then that value is used with a logarithmic
equation to calculate A
-calculated using Beer Lambert law
-has no units (units cancel each other out in the equation)
absorbed light Correct Answers light that enters a solution, and
is absorbed by the material
-the light comes into the solution does NOT pass through the
solution
absorption of hexoses Correct Answers hexoses will be used
depending on what the body needs at the time of absorption
-can be metabolized for energy (CO2 and H2O produced)
-glycogen storage in liver (until stores are full)
,-excess beyond glycogen needs is stored as triglycerides in fat
tissues (macromolecules in the body can be interconverted)
accuracy Correct Answers how close a measured result is to the
"desired" or "true" result
-was the measured result close to the acceptable value
ACTH (adrenocorticotropic hormone) Correct Answers
hormone that is released from the pituitary gland
-involved in feedback regulation of the release of cortisol
(causes the release of cortisol, but when cortisol is too high, this
hormone responds to negative feedback)
affinity chromatography (HbA1c) Correct Answers preferred
method for hemoglobin A1c
-normal hemoglobin is not attracted to tube, comes out in early
fraction
-hemoglobin A1c with extra sugar is attracted to tube and comes
out in late fraction
-not temperature dependent, takes 15 minutes, no reaction
interference with non-glycated hemoglobins
albuminuria Correct Answers increase in urinary albumin
excretion
-early sign of renal nephropathy
-diabetics should have annual urinary albumin excretion to
measure microablumin, checking for assessment of kidney
function
-persistent albuminuria: persistent contents in urine of 30-300
mg/g of creatinine is considered to be high
,amplitude Correct Answers the height of a wave
analytical activities (QC) Correct Answers evaluation of
activities occurring in the laboratory that deal with the analysis
of the patient sample
-calibration of instrument
-quality control (data analysis of acceptable control ranges)
-reference ranges: specific acceptable ranges based on different
patient populations
analytical measurement range Correct Answers the range of
analyte values that a test method can directly measure
-the range from the lowest to highest value that a instrument can
measure (wihtin the linearity of a method)
-the range of values which can be accurately measured by an
instrument (e.g. lithium can be measured between 0- 2.5
mmol/L)
-**if a patient sample is too high and not able to be read you
have to make a dilution and then multiple the result obtained by
the dilution factor**
Beer's law Correct Answers A=abc
-absorbance (A) is directly proportional to the concentration (c)
of the absorbing substance in a solution
-A= absorbance
-a= molar absorptivity
-b= light path through the solution
-c= concentration of substance
-all of the units that are multiplied together cancel each other
out, so there is no units for A
, blood glucose measurement Correct Answers -can be measured
in serum, plasma or whole blood
-serum or plasma tested within 1 hour of collection (decreases
occur due to use of glucose by RBCs and WBCs)
-fasting glucose should be measured after 8 to 10 hour fast (no
longer than 12 hours because glucagon spikes and causes blood
glucose to spike and falsely increase)
-common methods: glucose oxidase or hexokinase enzyme
assays
calculating absorbance Correct Answers **absorbance cannot
be directly measured**
-instrument is used to read %T
-instrument converts %T into absorbance
-instrument compares the sample absorbance with the known
absorbance of a standard (a known value at a certain
wavelegnth), and uses this to calculate the concentration of
analyte (using Beer's law)
calculating quality control range Correct Answers mean + and -
2 standard deviations
calibration curve Correct Answers establishes the relationship
between instrument signal (readings) and the concentration of
the analyte
-can be used to equate a certain absorbance value (given from
spectrophotometer) with concentration
calibrator (spectrophotometry) Correct Answers a single value
that establishes the relationship between instrument signal and
the concentration of an analyte
"out of control" Correct Answers errors can lead the WC
control to be out of the accepted +/- 2 standard deviation from
the mean range
absorbance assumptions Correct Answers to read absorbance 2
factors are assumed
-monochromatic light: it is assumed that only a single
wavelength of light is being used
-logarithmic relationship: as absorbance increases the %T (%
transmission of light) goes down logarithmically
absorbance Correct Answers a value that is CALCULATED
(not measured) based on %T to determine how much of the light
is absorbed
-%T is measured and then that value is used with a logarithmic
equation to calculate A
-calculated using Beer Lambert law
-has no units (units cancel each other out in the equation)
absorbed light Correct Answers light that enters a solution, and
is absorbed by the material
-the light comes into the solution does NOT pass through the
solution
absorption of hexoses Correct Answers hexoses will be used
depending on what the body needs at the time of absorption
-can be metabolized for energy (CO2 and H2O produced)
-glycogen storage in liver (until stores are full)
,-excess beyond glycogen needs is stored as triglycerides in fat
tissues (macromolecules in the body can be interconverted)
accuracy Correct Answers how close a measured result is to the
"desired" or "true" result
-was the measured result close to the acceptable value
ACTH (adrenocorticotropic hormone) Correct Answers
hormone that is released from the pituitary gland
-involved in feedback regulation of the release of cortisol
(causes the release of cortisol, but when cortisol is too high, this
hormone responds to negative feedback)
affinity chromatography (HbA1c) Correct Answers preferred
method for hemoglobin A1c
-normal hemoglobin is not attracted to tube, comes out in early
fraction
-hemoglobin A1c with extra sugar is attracted to tube and comes
out in late fraction
-not temperature dependent, takes 15 minutes, no reaction
interference with non-glycated hemoglobins
albuminuria Correct Answers increase in urinary albumin
excretion
-early sign of renal nephropathy
-diabetics should have annual urinary albumin excretion to
measure microablumin, checking for assessment of kidney
function
-persistent albuminuria: persistent contents in urine of 30-300
mg/g of creatinine is considered to be high
,amplitude Correct Answers the height of a wave
analytical activities (QC) Correct Answers evaluation of
activities occurring in the laboratory that deal with the analysis
of the patient sample
-calibration of instrument
-quality control (data analysis of acceptable control ranges)
-reference ranges: specific acceptable ranges based on different
patient populations
analytical measurement range Correct Answers the range of
analyte values that a test method can directly measure
-the range from the lowest to highest value that a instrument can
measure (wihtin the linearity of a method)
-the range of values which can be accurately measured by an
instrument (e.g. lithium can be measured between 0- 2.5
mmol/L)
-**if a patient sample is too high and not able to be read you
have to make a dilution and then multiple the result obtained by
the dilution factor**
Beer's law Correct Answers A=abc
-absorbance (A) is directly proportional to the concentration (c)
of the absorbing substance in a solution
-A= absorbance
-a= molar absorptivity
-b= light path through the solution
-c= concentration of substance
-all of the units that are multiplied together cancel each other
out, so there is no units for A
, blood glucose measurement Correct Answers -can be measured
in serum, plasma or whole blood
-serum or plasma tested within 1 hour of collection (decreases
occur due to use of glucose by RBCs and WBCs)
-fasting glucose should be measured after 8 to 10 hour fast (no
longer than 12 hours because glucagon spikes and causes blood
glucose to spike and falsely increase)
-common methods: glucose oxidase or hexokinase enzyme
assays
calculating absorbance Correct Answers **absorbance cannot
be directly measured**
-instrument is used to read %T
-instrument converts %T into absorbance
-instrument compares the sample absorbance with the known
absorbance of a standard (a known value at a certain
wavelegnth), and uses this to calculate the concentration of
analyte (using Beer's law)
calculating quality control range Correct Answers mean + and -
2 standard deviations
calibration curve Correct Answers establishes the relationship
between instrument signal (readings) and the concentration of
the analyte
-can be used to equate a certain absorbance value (given from
spectrophotometer) with concentration
calibrator (spectrophotometry) Correct Answers a single value
that establishes the relationship between instrument signal and
the concentration of an analyte
