Chapter 1: Clinical Chemistry — Instrumentation, Proteins, Lipids, Enzymes, Electrolytes, Endocrinology, Therapeutic Drug Monitoring, Toxicology, Vitamins

Vocabulary flashcards covering major terms and concise definitions from Chapter 1 notes on instrumentation, proteins, lipids, enzymes, electrolytes, acid-base, endocrinology, TDM, toxicology, and vitamins.

Albumin

Major plasma protein; maintains oncotic pressure and transports many ligands.

Globulins

Group of plasma proteins including alpha, beta, and gamma globulins with diverse functions.

Ferritin

Iron storage protein; reflects body iron stores.

Transferrin

Iron transport protein; its capacity (TIBC) and saturation reflect iron status.

Haptoglobin

Binds free hemoglobin; acute-phase reactant; decreased with intravascular hemolysis.

Ceruloplasmin

Copper-containing enzyme; acute-phase reactant; carries most serum copper.

C-reactive protein (CRP)

Acute-phase reactant; hs-CRP used as a cardiovascular risk marker.

α1-Antitrypsin

Acute-phase reactant; protease inhibitor with broad protective roles; increased in inflammation.

Fetoprotein (AFP)

Oncofetal glycoprotein; elevated in hepatocellular carcinoma and certain pregnancy conditions.

Prostate-Specific Antigen (PSA)

Prostate gland protein; biomarker for prostate cancer detection and monitoring.

CA 125

Mucin glycoprotein; marker for ovarian cancer and gynecologic malignancies.

CA 19-9

Glycolipid tumor marker associated with pancreatic, colorectal, and other cancers.

CA 15-3

Mucin glycoprotein marker used to monitor breast cancer.

Lipid Profile

Panel including total cholesterol, triglycerides, HDL, LDL (often via Friedewald equation).

Chylomicrons

Largest, least dense lipoproteins formed after meals; transport dietary triglycerides.

VLDL

Very-low-density lipoprotein; transports endogenous triglycerides from liver.

LDL

Low-density lipoprotein; major cholesterol carrier; elevated levels linked to atherosclerosis.

HDL

High-density lipoprotein; "good" cholesterol; helps remove cholesterol from tissues.

Lp(a)

Lipoprotein(a); an independent risk factor for cardiovascular disease.

Friedewald Formula

LDL = Total cholesterol – HDL – TG/5 (not valid if TG > 400 mg/dL).

Atherogenesis

Process of plaque buildup in arteries leading to cardiovascular disease.

Enzymes

Biological catalysts; proteins; elevated serum levels indicate tissue injury.

Isoenzymes

Different forms of the same enzyme with distinct kinetic properties or tissue distribution.

cTnI and cTnT

Cardiac troponins I and T; highly specific markers for myocardial infarction.

CK and CK-MB

Creatine kinase and CK-MB isoenzyme; markers for myocardial injury; CK-MB more cardiac-specific.

LD and LD Isoenzymes

Lactate dehydrogenase and isoenzymes (LD-1 to LD-5) used in MI and liver disease evaluation.

ALT and AST

Alanine and aspartate aminotransferases; ALT more liver-specific; AST found in other tissues.

Alkaline Phosphatase (ALP)

Enzyme elevated in hepatobiliary and bone disorders; placental ALP elevated in pregnancy.

Gamma-Glutamyl Transferase (GGT)

Enzyme sensitive for hepatobiliary disease; rises with alcohol-related liver disease.

Amylase and Lipase

Pancreatic enzymes; elevated in acute pancreatitis.

Glycated (Glycosylated) Hemoglobin (HbA1c)

Hemoglobin with glucose attached; reflects average blood glucose over 2–3 months.

Fructosamine

Glycated albumin; reflects short-term glucose control (2–3 weeks).

Glycemic tests (OGTT)

Oral glucose tolerance test assesses glucose handling over 2–3 hours; diagnostic criteria differ by guidelines.

GDM

Gestational diabetes mellitus; glucose intolerance that begins during pregnancy.

Insulin

Peptide hormone from pancreatic beta cells; lowers blood glucose by promoting uptake and storage.

Glucagon

Pancreatic alpha-cell hormone; raises blood glucose by promoting glycogenolysis and gluconeogenesis.

hCG

Human chorionic gonadotropin; pregnancy marker and tumor marker for certain germ cell/trophic tumors.

HPL

Human placental lactogen; placental hormone affecting maternal metabolism and fetal growth.

Vitamin A (Retinol)

Fat-soluble vitamin; essential for vision, epithelium; toxicity risk in excess.

Vitamin D

Fat-soluble vitamin; important for calcium/phosphate homeostasis; active form is 1,25-dihydroxyvitamin D3.

Vitamin E

Fat-soluble antioxidant vitamin.

Vitamin K

Fat-soluble vitamin essential for coagulation factor synthesis.

Glycogen

Branched polysaccharide; storage form of glucose in liver and muscle.

Glycogenolysis

Breaking down glycogen to glucose.

Glycolysis

Metabolic pathway converting glucose to pyruvate or lactate.

Gluconeogenesis

Synthesis of glucose from non-carbohydrate sources.

Ketone Bodies

Acetoacetate, beta-hydroxybutyrate, and acetone; produced during fat metabolism.

Aldosterone

Mineralocorticoid; regulates Na+ and water reabsorption; renin-angiotensin system controls its release.

Cortisol

Glucocorticoid; raises blood glucose via gluconeogenesis; diurnal secretion; feedback on ACTH.

Hemoglobin A

Adult Hb with two alpha and two beta chains.

Hemoglobin A2

Hb with two alpha and two delta chains; minor Hb in adults.

Hemoglobin F (Fetal Hb)

Hb with two alpha and two gamma chains; higher in fetus/newborns.

Triglyceride

Esterified fatty acids; elevated TG linked to pancreatitis and metabolic syndrome.

Chylomicron Turbidity

Creamy top layer in stored plasma caused by chylomicrons after a fat-rich meal.

Apo A-1

Major protein of HDL; antiatherogenic.

Apo B-100

Major protein of LDL and VLDL; associated with atherosclerosis risk.

Apo A-1, Apo B-100, Lp(a) measurements

Immunochemical methods to assess cardiovascular risk markers.

Kjeldahl Method

Reference method for protein nitrogen quantification; basis for total protein determination.

Biuret Method

Total protein assay based on cupric ion complexation with peptide bonds.

Hgb A1c Target (<7%)

Therapeutic goal for many diabetics to reduce microvascular complications.

Friedewald LDL formula validity

Best used when TG < 400 mg/dL; otherwise direct LDL methods preferred.

Hemoglobinopathies S and C

Sickle cell (valine substitution) and Hb C (lysine substitution) affecting electrophoretic mobility.

Isoelectric Point (pI)

pH at which a protein has no net charge and does not migrate in an electric field.

Buffer Systems in Blood

Bicarbonate, protein, phosphate, and hemoglobin buffers maintain pH.

GDM OGTT Two-Step Approach

Screen with 50-g GCT; if abnormal, follow with 100-g OGTT as per WHO/ADA criteria.

Bile Acids (Cholic/Chenodeoxycholic)

Liver-synthesized steroids conjugated with glycine or taurine; involved in fat digestion and cholesterol excretion.