Clinical Chemistry Practice Practicum

Comprehensive vocabulary flashcards covering clinical chemistry instrumentation, proteins, metabolic products, carbohydrates, lipids, enzymes, and endocrinology based on lecture clinical notes.

Wavelength ($\lambda$)

The distance traveled by one complete wave cycle (distance between two successive crests) measured in nanometers (nm).

Photons

Particles of light; when an atom absorbs one, the atom becomes excited by moving an electron to a higher energy level, changing covalent bond vibration, or changing bond rotation.

Bandpass

The range of wavelengths in nanometers transmitted by the monochromator and exit slit between two points where the light transmitted is one-half of the peak transmittance.

Atomic Absorption Spectrophotometry

A technique based on the principle that ground-state atoms absorb light at defined wavelengths; the difference between light leaving a hollow-cathode lamp and light measured by the detector is indirectly proportional to the metal analyte concentration.

Nephelometry

The measurement of light scattered by a particulate solution, where the amount of scatter is directly proportional to the number and size of particles present.

Turbidimetry

A measurement of light blocked as a decrease in the light transmitted through a solution, dependent on particle size and concentration.

Fluorescence

A process where atoms absorb energy at a particular wavelength, raising electrons to higher orbitals, which then release energy by emitting light of a longer wavelength and lower energy.

Thin-Layer Chromatography (TLC)

A type of planar chromatography where the stationary phase is typically silica gel coated on a glass or plastic plate and the mobile phase is a solvent; used clinically for urine drug screening.

Isocratic elution

An HPLC technique where the strength of the solvent remains constant during the separation process.

Mass Spectrometer

An instrument that separates ions according to their mass-to-charge ratios by moving charged particles through a magnetic or electric field.

Potentiometry

A technique used to determine the concentration of a substance in solution by measuring the potential difference between an indicator electrode and a reference electrode in an electrochemical cell.

Amperometry

An electrochemical technique measuring the amount of current produced through the oxidation or reduction of a substance at an electrode held at a fixed potential.

Isoelectric point (pI)

The pH at which the negative and positive charges on a protein are equal, resulting in a net charge of zero.

Zone electrophoresis

The movement of charged molecules in a porous supporting medium where molecules separate as distinct zones.

Dead volume

The amount of serum in a sample tube that cannot be aspirated by an automated instrument.

Throughput

The maximum number of laboratory tests generated per hour by an automated analyzer.

Competitive-binding immunoassays

Assays based on the competition between an unlabeled antigen (sample analyte) and a labeled antigen for a limited number of antibody binding sites.

Peptide bond

A bond formed when the carboxyl ($-COOH$) group of one amino acid links to the amino ($-NH_2$) group of another with the loss of one water molecule.

Simple proteins

Polypeptides composed of only amino acids, further classified into globular proteins (like albumin) and fibrous proteins (like collagen).

Acute-phase reactant proteins

Proteins whose synthesis by the liver is increased in response to cytokines released at the site of injury or inflammation.

Albumin

The plasma protein with the highest concentration; synthesized in the liver, it binds many analytes (bilirubin, calcium, drugs) and significantly contributes to plasma osmotic pressure.

Ceruloplasmin

An $\alpha_2$-globulin and acute-phase reactant that contains copper; approximately $90\%$ of serum copper is bound to this protein.

Bence Jones protein

Free light chains (kappa or lambda) found in the urine of patients with multiple myeloma.

Prostate specific antigen (PSA)

A glycoprotein protease produced by the prostate gland used as a marker for prostate cancer and benign prostate hypertrophy.

Urea

The major nitrogen-containing compound in the blood, resulting from protein catabolism and synthesized in the liver from the deamination of amino acids.

Creatinine

A waste product of muscle contraction formed from phosphocreatine; its level is used to assess the glomerular filtration rate (GFR).

Uric acid

The major waste product of purine (adenosine and guanine) catabolism, synthesized in the liver and regulated by the kidneys.

Insulin

A hormone produced by the beta cells of the pancreatic islets that promotes the entry of glucose into tissues and inhibits its release from the liver.

Glucosuria

A condition where glucose appears in the urine, typically occurring when blood glucose exceeds the renal threshold of $160-180\,mg/dL$.

Glycated hemoglobin ($Hb A_{1c}$)

The main form of glycated hemoglobin, formed by the nonenzymatic attachment of glucose to hemoglobin $A_1$; it reflects blood glucose levels over the previous 2–3 months.

Type A Lactic acidosis

Lactic acidosis caused by depressed oxygen levels, which may occur in instances like acute myocardial infarction or congestive heart failure.

Triglyceride

A lipid formed from one glycerol molecule with three fatty acid molecules attached via ester bonds; comprises $95\%$ of all fats stored in adipose tissue.

Very-low-density lipoprotein (VLDL)

A lipoprotein that carries endogenous triglycerides synthesized in the liver.

Low-density lipoprotein (LDL)

Known as "bad cholesterol," it is the body's major cholesterol carrier and elevated levels are associated with increased risk for atherosclerosis.

High-density lipoprotein (HDL)

Known as "good cholesterol," it removes excess cholesterol from peripheral tissues and transports it to the liver, providing an antiatherogens effect.

Friedewald formula

A formula used to calculate LDL: $LDL\text{ cholesterol} = \text{total cholesterol} - [HDL\text{ cholesterol} + \frac{\text{triglyceride}}{5}]$.

Isoenzyme

Different forms of the same enzyme capable of the same catalytic function, often differentiated by electrophoretic mobility.

Zero-order kinetics

A state in an enzyme reaction where substrate is present in excess and the reaction rate depends only on the concentration of the enzyme.

Creatine kinase (CK)

An enzyme found in high concentrations in skeletal muscle, heart muscle, and brain tissue; its CK-MB fraction is used as a marker for heart muscle damage.

Bilirubin

The principal pigment in bile derived from hemoglobin breakdown; it is conjugated in the liver with glucuronic acid to become water soluble.

Kernicterus

A condition in infants where elevated bilirubin deposits in brain tissue, potentially causing mental retardation.

Gilbert syndrome

A defect in the ability of hepatocytes to take up bilirubin, characterized by a mild increase in unconjugated bilirubin.

Crigler-Najjar disease

A syndrome caused by a deficiency of UDP-glycuronyltransferase, leading to high levels of unconjugated bilirubin.

Anion gap

A mathematical formula ($Na^+ - (Cl^- + HCO_3^-)$) used to demonstrate the electroneutrality of body fluids.

Tetany

Muscle spasms or uncontrolled contractions caused by decreased levels of free (ionized) calcium.

Ferritin

A protein that reflects iron stores in the body and serves as a sensitive, early indicator of iron-deficiency disorders.

Henderson-Hasselbalch equation

An equation used to relate blood pH, bicarbonate, and $PCO_2$: $pH = 6.1 + \log \frac{[HCO_3^-]}{[PCO_2 \times 0.03]}$.

Thyroid-stimulating hormone (TSH)

A polypeptide hormone from the anterior pituitary that regulates the synthesis and release of thyroid hormones ($T_3$ and $T_4$).

Steady state

The condition in therapeutic drug monitoring where the peak and trough levels are assessed, usually achieved after seven doses of a drug.

Trough level

The lowest concentration of a drug in the blood, measured by drawing a sample right before the next dose is administered.