Exam 4 - Enzymes, Endocrinology, Tumor Markers, TDM Exam Questions And Answers Pass Guaranteed Pass.

Define energy of activation - correct answers Amount of energy required to energize 1 mole of substrate to form an activated complex Define first-order kinetics - correct answers Velocity is nearly LINEAR with respect to substrate concentration Define zero-order kinetics - correct answers PLATEAU; Reaction is independent of substrate concentration Which order of enzyme kinetics describes the reaction rate when all the substrate is bound to enzymes? - correct answers Zero-order kinetics Describe factors that influence enzyme action - correct answers Substrate concentration Temperature pH Activators/cofactors/inhibitors Describe isoenzymes - correct answers Multiple forms of an enzyme that cause the same reaction Can be structurally different or specific to an organ/tissue What enzymes relate to the heart - correct answers Creatine kinase (CKMB) Lactate dehydrogenase (LD) AST What enzymes relate to the liver - correct answers AST, ALT What enzymes relate to the biliary tract - correct answers ALP, GGT, 5'-Nucleotidase What enzymes relate to the digestive system and pancreas - correct answers Amylase (AMY), lipase (LPS) What organs does lactate dehydrogenase originate from - correct answers Cardiac and skeletal muscle Liver Kidneys RBCs/WBs Lungs Lymph nodes Spleen Brain What enzyme originates from the *prostate*, bone, liver, spleen, kidneys, RBCs, and PLTs - correct answers Acid phosphatase Name the 3 creatine kinase isoenzymes - correct answers CK-1 = BB (brain) CK-2 = MB (heart) CK-3 = MM (muscle) What conditions cause an elevation in creatine kinase - correct answers Myocardial infarction Other disease affecting muscle, brain, and heart What is the reference range for creatine kinase - correct answers 25-170 U/L Where is lactate dehydrogenase located within cells - correct answers Cytoplasm What conditions cause an elevation in lactate dehydrogenase - correct answers Anemias (highest levels!) MI, shock, myocarditis, CHF Reference range for lactate dehydrogenase - correct answers 100-225 U/L What conditions cause an increase in AST - correct answers MI, CHF, pericarditis, myocarditis !!! Viral hepatitis, cirrhosis, alcoholic hepatitis, Reye's syndrome Skeletal muscle disorders Reference range of AST - correct answers 5-30 U/L What conditions cause an increase in ALT - correct answers Acute viral hepatitis, toxic hepatitis, obstructive liver disease, hepatic cancer, cirrhosis, viral hepatitis, acute inflammatory disease Reference range of ALT - correct answers 6-37 U/L What conditions cause an increase in ALP (include ranges above upper limit) - correct answers 3x upper limit = biliary tract obstruction 3-10x upper limit = obstructive liver disease *Also increased in bone disorders Reference range for ALP - correct answers 44-147 U/L What conditions cause an increase in GGT - correct answers Cholestasis, biliary obstruction, hepatocellular disease, chronic alcoholism Also pancreatitis, diabetes, and MI Reference range of GGT - correct answers 45 U/L Where is 5'-Nucleotidase located in the body - correct answers Biliary epithelium Use of 5'-Nucleotidase - correct answers Aids in determining if ALP is elevated in bone or liver disease Reference range of 5'-Nucleotidase - correct answers 2-15 U/L What conditions cause an increase in amylase - correct answers Acute pancreatitis, obstructive liver disease, acute alcoholism, other acute pancreatic conditions Reference range for serum amylase - correct answers 40-140 U/L Reference range for urine amylase - correct answers 24-400 U/L Function of lipase - correct answers Breaks down fat linkages to produce alcohols and fatty acids Reference range for lipase - correct answers 10-200 U/L Why is lipase a better indicator of pancreatitis than amylase - correct answers Lipase is more pancreas-specific, while amylase also includes salivary amylase Amylase is cleared by the kidneys so lipase stays elevated longer What conditions cause an increased acid phosphatase - correct answers Prostate diseases, forensics, bone disorders Reference range for acid phosphatase - correct answers = 2.1 ng/mL List the 3 characteristics of a good cardiac biomarker - correct answers Released rapidly → providing specific and sensitive information about MI injury Persists in circulation → can be detected late Detectable at a low concentration Note how long each each cardiac troponin is elevated in AMI - correct answers TnT is elevated for 8-21 days TnI is elevated for 7-14 days How long is CK elevated in AMI - correct answers 3-4 days How long is myoglobin elevated in AMI - correct answers 28 hours What cardiac troponins are preferential for detecting myocardial necrosis - correct answers cTnI and cTnT Define myoglobin - correct answers The iron and oxygen binding protein found exclusively in muscle and normally absent from circulation Why is myoglobin not a primary marker of AMI - correct answers Has a very short half life and not heart specific Function of troponin - correct answers Muscle contraction Define the 3 subunits of troponin - correct answers cTnT → binds Tropomyosin cTnI → binds actin and Inhibits contraction cTnC → contains 4 Calcium and regulates Contraction State how Tn levels change during AMI - correct answers Ride in 4-6 hours Peaks in 10-24 hours Returns to normal in a couple days State how CKMB levels change during acute MI - correct answers Ride in 4 hours Peaks in 18 hours Returns to normal in 2 days What methodology of measurement is used to detect troponins - correct answers Immunochemical Describe BNP and when it is released - correct answers BNP is released from cardiac ventricles and increased in CHF Differentiate CRP and hs-CRP -