Clinical Chemistry and Enzymology Practice Flashcards

Vocabulary practice flashcards covering clinical chemistry, enzymology, blood components, sample handling, liver, kidney, pancreatic, protein, and electrolyte assays based on lecture notes.

Erythrocytes

Red blood cells that form part of the cellular portion of whole blood.

Leukocytes

White blood cells contained within the cell portion of whole blood.

Thrombocytes

Also known as platelets, these are the smallest formed elements of blood and are involved in blood clotting.

Plasma

The fluid portion of whole blood consisting of $90\%$ water and $10\%$ dissolved constituents such as proteins, carbohydrates, enzymes, hormones, lipids, and salts.

Serum

The straw-colored fluid portion of blood left over after blood cells and fibrinogen (a clotting factor) have been separated from whole blood ($\text{Plasma} - \text{Fibrinogen} = \text{Serum}$).

In-vitro

Literally meaning "within a glass"; describes processes occurring outside the living body in a test tube or artificial environment.

In-vivo

Refers to biological processes occurring within the living body.

Tiger top tube

Also known as a serum separator tube; designed to clot blood and separate serum from cells, making it the best tube for accurate glucose analysis.

Green top tube

A blood collection tube containing lithium heparin; the tube of choice when plasma or electrolyte analysis is required, and for avian and reptile blood samples.

Hemolysis

The rupture of red blood cells caused by improper sample collection or handling, imparting an orange or red color to serum or plasma.

Lipemia

An excess of lipids in the blood often seen post-prandially ($4\text{--}6\text{ hours}$ after a meal), causing serum to appear cloudy pink or white.

Enzymes

Proteins produced inside cells that act as catalysts to facilitate chemical reactions while remaining unchanged at the end of the reaction.

Reference Ranges

A set range of values defining normal levels for a particular blood constituent, established by repeatedly testing clinically normal animals of a given species.

Catalyst

An enzyme or substance that speeds up a chemical change.

Substrate

The specific substance upon which an enzyme acts to undergo a chemical change.

Product

The end result of an enzymatic reaction created through the interaction of an enzyme and its substrate.

International Unit (IU/ml)

The unit of measurement for enzyme assays, defined as the amount of enzyme that catalyzes the conversion of $1\,\mu\text{mol}$ of substrate per minute under specified assay conditions.

Endpoint Assay

A colorimetric assay method that uses a reagent to produce color in the product, where higher color intensity indicates greater enzyme concentration.

Kinetic Assay

An assay method that measures the rate of an enzymatic reaction while it is in progress through serial product concentration measurements.

Hepatocellular Damage

Injury or destruction affecting individual liver cells (hepatocytes).

Cholestasis

The blockage or stoppage of bile flow from the liver and/or gallbladder.

Alanine Aminotransferase (ALT)

An enzyme (formerly SGPT) used to detect hepatocellular damage in dogs, cats, and primates; not valid for horses, ruminants, or pigs.

Aspartate Aminotransferase (AST)

An enzyme (formerly SGOT) present in liver cells, muscle cells, and erythrocytes that elevates with non-specific liver damage, exercise, or intramuscular injections.

Sorbitol Dehydrogenase (SD)

An enzyme specific for hepatocellular damage or necrosis in all mammals, commonly used as an ALT replacement in large animals.

Glutamate Dehydrogenase (GD)

An enzyme recommended for diagnosing hepatocellular damage and necrosis specifically in ruminants, sheep, and goats.

Alkaline Phosphatase (AP or ALP)

An enzyme used to diagnose cholestasis in dogs and cats, originating primarily from bone growth in young animals and liver cells in older animals.

Gamma Glutamyltranspeptidase (GGT)

A liver-specific enzyme indicator for biliary and obstructive liver disorders in dogs and cats; also assayed in large animals.

Bilirubin

A metabolite of the heme portion of hemoglobin generated during erythrocyte breakdown, conjugated by the liver and evaluated to assess liver function and bile duct patency.

Bile Acids

Substances produced from cholesterol by the liver and secreted into intestines for fat digestion, evaluated pre- and post-prandially to assess liver function and portal recirculation.

Blood Urea Nitrogen (BUN)

A renal test measuring urea, a non-toxic nitrogenous product of amino acid breakdown produced by the liver and filtered from blood by the kidneys.

Creatinine

A metabolic byproduct of creatine filtered by kidney glomeruli and eliminated in urine, used to evaluate glomerular filtration.

Azotemia

An abnormal blood condition characterized by concurrent elevations in both Blood Urea Nitrogen (BUN) and Creatinine, indicating possible kidney disease.

Trypsin

An exocrine pancreatic enzyme that aids digestion by catalyzing the breakdown of proteins.

Amylase

An exocrine enzyme secreted by the pancreas, salivary glands, and stomach that functions to break down starches and sugars.

Lipase

An exocrine pancreatic enzyme responsible for breaking down long-chain fatty acids of lipids.

Pancreatic-Specific Lipase

A form of lipase produced exclusively in the pancreas, measured via tests such as cPLI or fPLI to detect pancreatic inflammation.

Glucose

A blood assay measuring carbohydrate metabolism and endocrine pancreatic function, reflecting the balance between insulin and glucagon.

Creatine Kinase (CK)

An organ-specific enzyme produced mainly in skeletal muscle, cardiac muscle, and brain tissue that elevates following muscle damage or prolonged recumbency.

Lactate Dehydrogenase (LDH)

A non-specific enzyme indicator of tissue necrosis produced by the liver, skin, kidneys, muscles, and blood cells.

Lactate

A blood parameter reflecting anaerobic metabolism, utilized to detect cellular oxygen deprivation and hypoperfusion in critically ill patients.

NT-proBNP

A feline cardiac biomarker assay that measures stretch and stress on the myocardium to evaluate cardiac disease.

Total Protein

The cumulative measurement of circulating plasma or serum proteins (albumin, globulins, and fibrinogen), synthesized in the liver and plasma cells.

Albumin

The primary plasma protein, comprising $35\text{--}50\%$ of circulating blood proteins, produced by the liver and responsible for maintaining osmotic pressure and binding transport.

Globulins

A group of plasma proteins consisting of alpha (transport/binding), beta (iron transport and fibrin lysis), and gamma (antibody production) fractions.

Fibrinogen

Clotting factor 1 synthesized by hepatocytes, making up $3\text{--}6\%$ of total plasma proteins, which converts into fibrin threads to form blood clots.

Electrolytes

Anions and cations in bodily fluids that function in acid-base balance, water distribution, osmotic pressure, and nerve/muscle regulation.

Calcium ($\text{Ca}^{2+}$)

An electrolyte functioning in nerve impulse transmission, muscle contractions, blood clotting, and bone structure, $50\%$ of which is bound to albumin in blood.

Inorganic Phosphorous ($\text{PO}_4^{2-}$)

An electrolyte in plasma and serum involved in energy storage and transfer, carbohydrate metabolism, and nucleic acid composition; shares an inverse relationship with calcium.

Sodium ($\text{Na}^+$)

The major cation of plasma and extracellular fluid, essential for water distribution, osmotic pressure regulation, and acid-base balance.

Potassium ($\text{K}^+$)

The primary intracellular cation responsible for muscular function, respiration, cardiac rhythm, nerve impulse transmission, and carbohydrate metabolism.

Magnesium ($\text{Mg}^{2+}$)

The second most common intracellular cation, involved in activating enzyme systems and regulating acetylcholine release at neuromuscular junctions.

Chloride ($\text{Cl}^-$)

The most abundant extracellular anion, responsible for maintaining water distribution, osmotic pressure, and anion/cation ratios.

Bicarbonate ($\text{HCO}_3^-$)

The second most common plasma anion, acting as a major systemic buffer to maintain proper acid-base pH balance.