Flashcards in C13 Enzymes Deck (70):
Special group of catalysts that are made up of proteins, speed up reaction
How are enzymes measured?
substances that lessen the amount of energy required for chemical reactions to occur
Enzyme (structure) Primary
amino acid sequence
Enzyme (Structure) Secondary
interaction between 2 locations on protein chain
Enzyme (structure) Tertiary
folding of chains (3D structure)
Enzyme (structure) Quadernary
2 or more separate polypeptide chains
physical location on the enzyme molecule which interacts w/ substrate molecule
non active site, but which may interact w/ other substances to change overall enzyme 3D shape
structurally diff enzymes (proteins) but which catalyze the same chemical reactions
a non protein substance required for normal enzyme activity, maintain enzyme 3D structure, critical for enzyme function
2 types of cofactors?
activators (inorganic) & coenzyme (organic)
Enzyme+coenzyme (prosthetic group)=active enzyme
The amount of energy required to stimulate molecules to break their chemical bonds and form new bonds is the ___.
absolute type enzymes
catalyzes only 1 specific substrate
Group type enzymes
catalyzes reactions of a particular chemical group
Bond type enzyme
catalyzes reactions of particular chemical bonds
catalyzes reactions of steroisomers
What does the substrate do?
saturates enzymes (all enzymes react with excess substrate)
the rate at which an enzyme catalyzes a chemical reaction
Why is activity measured under Zero Order conditions?
because this is where the reaction rate is dependent on the work (activity) of the enzyme
substances that bind at the enzyme's site, competes with substrate for the active site, addition of additional substrate increases the reaction rate
substances that bind at an enzyme's non-active site, enzyme 3d shape is altered, decreasing enzyme activity, may bind substrate but additional substrate has no effect
substances that bind with enzyme-substrate complex
How can enzyme activity be measured?
increase of product, decrease of substrate, decrease of co-enzymes, and increase of altered co-enzyme
substrate concentration is measured at set time intervals to determine enzyme activity
What is a slight delay from the beginning of the reaction to max velocity?
extreme elevations in enzyme activity may deplete the substrate between measured intervals, causes falsely decreased activity results
Multipoint Continuous Monitoring (Kinetic Assay)
continuous measurements of substrate-product concentration are recorded by the spectrophotometer of an automated analyzer
What is the common unit of enzyme activity?
International Unit (IU)
that amount of enzyme that will convert 1 micro-mole of substrate to product per minute under defined conditions
Common co-enzyme, absorbs light at 340 NM
Why are enzymes used as reagents?
to measure other non-enzymes
High concentrations of CPK are found in?
muscle, cardiac & brain tissues
Increased CPK is associated with?
damage to the muscle, cardiac, and brain tissues
Increased CPK is useful to diagnose?
AMIs and skeletal muscle disease (muscular dystrophy)
How many isoenzymes does CPK have?
Because of CK-MBs association with cardiac tissue, increased CPK-MB (>_6% Total CPK activity) is a strong indication of?
Lactate dehydrogenase is found in what tissues?
skeletal muscle, cardiac muscle, renal tissue, and RBCs
Plasma LDH is elevated in what conditions?
Liver disease, cancers, AMI, hemolytic diseases
How many isoenzymes does LDH have?
(HHHH) Cardiac, RBCs
(HHMM) lung, spleen, pancreas
(HMMM) hepatic, skeletal
Aspartate aminotransferase high concentrations are found in?
skeletal muscle, cardiac muscle, liver tissue, and lung tissue
Alanine aminotransferase has the highest activity in the?
alkaline phosphate does what?
removes phosphates from organic compounds
alkaline phosphate has higher concentrations in?
bone and liver
what group of people have higher ranges of alkaline phosphate?
children, because they are still growing
Amylase catalyzes breakdown of?
starch and glycogen to glucose
High concentrations of amylase are found in?
pancreas and saliva
amylase is filtered into the?
increased plasma or urine amylase is very sugguestive of?
pancreatitis or pacreatic malignancy
Gamma glutamyltransferase has high concentrations in the?
increased plasma GGT is associated with?
hepatobiliary disease & alcoholic cirrhosis
Lipase hydrolyzes (break down)?
high concentrations of lipase are found in?
pseudocholinesterase is considered a screening test for exposure to?
organophosphate exposure (pesticides)
3 step in diagnosing AMI?
1-symptoms, physical exam, patient history
Myoglobin is a soluble?
two forms of Troponin?
Troponin I and Troponin T
Cardiac enzymes, "CAL 911"
CPK, AST, LDH
What is the "triage" used for?
common commercial test package that quantitates the 3 most significant lab markers for AMI: CK-MB, Troponin I, and Myoglobin