Clinical Chemistry Panels & Enzymes – Key Vocabulary

Vocabulary flashcards covering essential laboratory analytes, normal values, disorders, lipid profiles, and clinical enzymes discussed in the Chemistry Panels lecture.

Basic Metabolic Panel (BMP)

Routine chemistry profile including Na, K, Cl, CO2, Anion Gap, BUN, Creatinine, Glucose, Calcium, eGFR.

Comprehensive Metabolic Panel (CMP)

BMP plus liver function tests (AST, ALT, ALP, total protein, albumin, globulin, A/G ratio, bilirubin).

Blood Urea Nitrogen (BUN)

Nitrogenous end-product of protein catabolism; used to assess renal function. Normal 10-20 mg/dL.

Azotemia

Elevated BUN; categorized as prerenal, renal, or postrenal.

Prerenal Azotemia

BUN elevation due to reduced kidney perfusion (e.g., CHF, shock, dehydration).

Renal Azotemia

Elevated BUN from intrinsic kidney disease causing acute renal failure.

Postrenal Azotemia

Raised BUN from obstruction of urinary outflow (both kidneys affected).

Uremia

Toxic condition of high serum urea accompanied by renal failure signs.

Creatinine

Waste product proportional to muscle mass; best single indicator of GFR. Normal 0.6–1.2 mg/dL (♂), 0.5–1.1 mg/dL (♀).

BUN/Creatinine Ratio

Index to differentiate azotemia causes; high = prerenal, low = ATN, liver disease, starvation.

Uric Acid

Purine metabolism end product; elevated levels linked to gout. Goal <6 mg/dL in gout therapy.

Gout

Inflammatory arthritis caused by monosodium urate crystal deposition in joints.

Magnesium (Mg)

Cofactor for >300 enzymes; normal 1.5–2.0 mEq/L.

Hypomagnesemia

Low Mg frequently in ICU; causes include diarrhea, diuretics, alcoholism; leads to arrhythmias & tetany.

Hypermagnesemia

High Mg from excess intake or renal failure; causes depressed reflexes & respiratory depression.

Calcium (Ca)

Mineral for bone, muscle, cardiac function; normal total 9-10.5 mg/dL.

Parathyroid Hormone (PTH)

Hormone raising serum calcium by mobilizing bone stores with vitamin D.

Calcitonin

Hormone from thyroid that lowers serum calcium by inhibiting PTH effects.

Hypocalcemia

Total Ca <9 mg/dL; critical <6 mg/dL; causes tetany, seizures, hypotension.

Hypercalcemia

Total Ca >10.5 mg/dL; critical >12 mg/dL; commonly due to hyperparathyroidism or malignancy.

Phosphate (PO₄³⁻)

Key intracellular anion for ATP & RBC O₂ release; normal 3.0-4.5 mg/dL; inversely related to Ca.

Hypophosphatemia

Low phosphate from alkalosis, refeeding, antacids; leads to muscle weakness & respiratory failure.

Hyperphosphatemia

High phosphate often from renal failure or vitamin D excess; can cause tetany & seizures.

Total Protein

Sum of serum proteins (albumin + globulins); normal 6.5-8.5 g/dL.

Albumin

Major plasma protein maintaining oncotic pressure; part of CMP.

Bilirubin

Heme breakdown product; measured as total, direct (conjugated) and indirect (unconjugated).

Jaundice

Yellow discoloration from elevated bilirubin.

Gilbert’s Syndrome

Benign inherited unconjugated hyperbilirubinemia due to reduced glucuronyltransferase.

Crigler-Najjar Syndrome

Rare severe deficiency or absence of UDP‐glucuronyl transferase causing high unconjugated bilirubin.

Prehepatic Jaundice

Bilirubin elevation due to hemolysis before liver uptake.

Hepatic Jaundice

Hyperbilirubinemia from intrinsic liver disease.

Posthepatic Jaundice

Conjugated bilirubin elevation from bile duct obstruction (e.g., gallstone).

Lipid Panel

Measures cholesterol, triglycerides, HDL, LDL, ±VLDL & risk ratio.

Cholesterol

Steroid component of membranes & hormones; goal <200 mg/dL.

Low-Density Lipoprotein (LDL)

"Bad" cholesterol carrier; goal <100 mg/dL (low risk) or <70 mg/dL (high risk).

High-Density Lipoprotein (HDL)

"Good" cholesterol transporting excess cholesterol to liver; protective when >45 mg/dL (♂) or >55 mg/dL (♀).

Triglycerides

Energy-storage lipids; normal <160 mg/dL (♂), <135 mg/dL (♀); very high levels risk pancreatitis.

Hypertriglyceridemia

Elevated triglycerides from diet, diabetes, ETOH, genetics; >1000 mg/dL may cause pancreatitis.

Apolipoprotein B (apoB)

Structural protein on VLDL, IDL, LDL; reflects number of atherogenic particles; goal <90 mg/dL in high-risk patients.

Acid Phosphatase

Enzyme highest in prostate; elevated in metastatic prostate cancer; normal 0-5 U/dL.

Prostate-Specific Antigen (PSA)

Preferred screening marker replacing acid phosphatase for prostate cancer.

Creatine Kinase (CK)

Muscle enzyme producing ATP; isoenzymes CK-MM (muscle), CK-MB (cardiac), CK-BB (brain).

CK-MB

Cardiac-specific CK isoenzyme; rises 3-6 h post-MI, peaks 12-24 h, normal by 48 h.

Troponin T/I

Cardiac regulatory proteins; most specific MI markers; rise 2-4 h, remain ↑ 7-14 days.

Lactate Dehydrogenase (LDH)

Ubiquitous enzyme elevated with tissue damage; nonspecific; rises 24-48 h post-MI.

Myoglobin

Early but nonspecific muscle protein; rises 1-2 h after MI, normal by 12 h.

Alkaline Phosphatase (ALP)

Enzyme of bone & hepatobiliary tissues; elevated in biliary obstruction & bone disease; normal 30-120 IU/L.

Amylase

Salivary/pancreatic enzyme converting starch to sugar; rises in acute pancreatitis; normal 60-120 IU/L.

Lipase

Pancreatic enzyme hydrolyzing triglycerides; more specific for pancreatitis; normal 0-160 IU/L.

Alanine Aminotransferase (ALT)

Liver-predominant transaminase; elevated in hepatocellular injury; normal 5-35 IU/L.

Aspartate Aminotransferase (AST)

Transaminase found in liver, heart, muscle; elevated in liver disease & MI; normal 0-35 IU/L.

Gamma-Glutamyltransferase (GGT)

Enzyme of liver & biliary tract; sensitive for alcohol-related or obstructive liver disease; normal 8-38 IU/L.

Paget’s Disease

Bone disorder with extremely high ALP (10-25× UL) due to osteoblast activity.

Rhabdomyolysis

Severe muscle breakdown causing CK-MM elevations 5–10× normal and risk of renal failure.

Acute Pancreatitis

Inflammation of pancreas marked by high lipase (>2-50× UL) and amylase; symptoms include epigastric pain.

Biliary Obstruction

Blockage of bile flow causing marked ALP and GGT elevations; extrahepatic obstruction >3× UL.

Tangier Disease

Genetic absence of HDL leading to cholesterol accumulation in tonsils and tissues.

Anion Gap

Calculated parameter (Na + K) – (Cl + CO₂); normal 8-12 mEq/L; identifies metabolic acidosis.

Estimated GFR (eGFR)

Calculated filtration rate; >60 mL/min considered normal kidney function.

Chylomicron

Largest lipoprotein carrying dietary triglycerides from intestine to tissues.

Very-Low-Density Lipoprotein (VLDL)

Lipoprotein rich in triglycerides; precursor of LDL in circulation.

Isoenzyme

Different molecular form of an enzyme that catalyzes the same reaction but is tissue-specific (e.g., CK-MB).

Refeeding Syndrome

Electrolyte shifts (notably phosphate drop) after nourishment of malnourished patients.

Myocardial Infarction (MI)

Cardiac muscle necrosis diagnosed using biomarkers (troponin, CK-MB) and clinical findings.