Enzymes Flashcards
General properties of Enzymes
_________: Water Free
Allosteric site: __________
Active Site: Water Free
Allosteric site: Cavity other than active site
Has the same catalytic reaction but have different molecular structure
Isoenzyme
Cofactor is a _________ molecule
Non-protein molecule
3 Types of Cofactors
Coenzyme
Activator
Metalloenzyme
Coenzyme: __________
Activator: _________
Metalloenzyme: __________
COenzyme: Organic Molecule/compound Cofactors
ActIvator: Inorganic ions Cofactors
Metalloenzyme: Inorganic Cofactors
The coenzyme is called ____________ when its tightly bound to the enzyme.
Prosthetic group
Inactive form of enzymes
Zymogens
Enzyme portion
Apoenzyme
Apoenzyme + Coenzyme = ___________
Holoenzyme
Functions of Enzyme Classification
Oxidoreductases: \_\_\_\_\_\_\_\_\_\_\_ Transferases: \_\_\_\_\_\_\_\_\_\_\_ Hydrolases: \_\_\_\_\_\_\_\_\_ Lyase: \_\_\_\_\_\_\_\_\_\_ Isomerases: \_\_\_\_\_\_\_\_ Ligase: \_\_\_\_\_\_\_\_\_\_
Oxidoreductases: removal or addition of electrons (REDOX)
Transferases: Transfer of chemical grp (except H) from substrate to substrate
Hydrolases: Splitting of bond by addition of water
Lyase: Removal of chemical grp w/o hydrolysis
Isomerases: change arrangement of substrate compound
Ligase: Synthesis or Joining of two substrate
Theory which the shape of the enzyme (lock) must fit with the substrate (key)
Lock and Key Theory (Emil Fischer)
Temperature at which Enzymes are ACTIVE
25C, 30C, 37C
Optimum temperature for Enzyme Activity
37C
Temperature at which enzyme starts to denaturate
40C - 50C
Temperature at which enzyme is INACTIVATED
60C - 65C
Function of Creatinine Kinase
Transfer of phosphate group between Creatine phosphate and ADP
_____________ is a sensitive indicator for AMI and Muscular Dystrophy (Duchenne disorder).
Creatinine Kinase
CK’s highest level is seen in __________________
Duchenne’s Muscular Dystrophy (50-100x)
Different Isoenzymes of CK
CK 1 - CK BB
CK 2 - CK MB
CK 3 - CK MM
Electrophoretic Pattern of CK
CK BB > CK MB > CK MM
Predominant CK function
Muscle Cells
Brain Type - CK
CK BB
Muscle Type - CK
CK MM
Hybrid Type - CK
CK MB
CKs major isoenzyme fraction found in striated muscle and serum
CK MM
Demonstration of elevated levels of CK MB, greater than or equal to _____ of the total CK, is considered to be the most specific indicator of _________________.
Specific indicator of AMI - =/> than 6%
Forward Reaction in CK Determination
Tanzer-Gilbarg Assay
Reverse Reaction in CK Determination
Oliver-Rosalky Assay
Most commonly used in CK Determination
Oliver-Rosalky Assay
It partially restore lost activity of CK
Cleland’s reagent and Glutathione
Added in Reverse reaction (Oliver-Rosalky) that inhibits adenylate Kinase
Adenosine monophosphate
______________ is released after red cell lysis and reacts with ADP to produce ATP
Adenylate Kinase
Contains no CK
Liver Cells
RBCs
Catalyzes the interconversion of lactic acid and pyruvic acid
Lactate dehydrogenase
Highest level of LDH is seen in __________________ & __________, increased from 10-50x
Pernicious Anemia
Hemolytic Disorders
LDH is tenfold increase in _____________ & ___________
Hepatic Carcinoma
Toxic Hepatitis
LDH Isoenzymes & Chain Composition
LDH 1: \_\_\_\_\_\_ LDH 2: \_\_\_\_\_\_ LDH 3: \_\_\_\_\_\_ LDH 4: \_\_\_\_\_\_ LDH 5: \_\_\_\_\_\_
LDH Isoenzymes & Chain Composition
LDH 1: HHHH LDH 2: HHHM LDH 3: HHMM LDH 4: HMMM LDH 5: MMMM
Most abundant and Major Isoenzyme of LDH
LDH 2
LDH isoenzyme that is relatively abundant in cardiac muscles
LDH 1
LDH isoenzyme that is more abundant in skeletal muscle
LDH 5
Tissue Sources
LDH 1 &2: _________, _________, _________
LDH 3: _________, _________, _________
LDH 4 & 5: _________, _________, _________
LDH 1 &2: Heart, RBC, Kidney
LDH 3: Lungs, Pancreas, Lymphocytes, Spleen
LDH 4 & 5: Skeletal muscle, Liver, Intestines
Flipped Pattern: ____________ is associated to - AMI and Hemolytic Anemia
LDH 1 > LDH 2
Electrophoretic pattern of LDH isoenzyme
SLOWEST ——— FASTEST
LDH 5 > LDH 4 > LDH 3 > LDH 2 > LDH 1
LDH isoenzyme concentration in Normal Serum
LDH 2 > LDH 1 > LDH 3 > LDH 4 > LDH 5
Forward Reaction: LDH Determination
Walker Method
Reverse Reaction: LDH Determination
Wrobleuski La due Method
Preferred Method in LDH Determination
Wrobleuski La due Method
A substrate added to lactate which have greater affinity to H subunits
a-hysroxybutyrate
AST is also known as ______________
SGOT
AST - Major isoenzymes
Cytoplasmic
Mitochondrial
AST - Major Tissue Sources
HEARTmore cardiac specific
Liver
Skeletal muscle
AST - Clinical Significance
AMI
Hepatocellular disorders
Skeletal muscle involvement - Reyes Syndrome
AST starts to rise in AMI within _________ hrs
6-8 hrs
Peak of AST levels in AMI
24 hrs
Method used in AST determination
Karmen Method & Frankel
Karmen method uses __________________ as an indicator reaction to monitor change in absorbance at 340 nm
Malate Dehydrogenase
ALT is also known as ______
SGPT
Major Tissue Source of ALT
LIVER
More Liver specific than AST
ALT
Highest elevation of ALT is found in __________
Acute Liver Hepatitis
Method used in ALTDetermination
Rietman & Frankel
____________ ratio between AST and ALT which is useful in determining the cause of Liver disease
De Ritis Ratio
ALP Isoenzymes
Intestinal ALP
Placental ALP
Liver ALP
Bone ALP
Most predominamt fractions of ALP
Liver and Bone
Carcinoplacental ALP
Regan
Nagao
Kasahara
Electrophoretic pattern of ALP isoenzymes
cathode —– anode
Intestinal > Placental > Bone > Liver
Most Heat Stable NORMAL ALP Isoenzyme
Placenta
Heat stability of ALP Isoenzyme
Placenta > Intestinal > Liver > Bone
Most Heat stable ALP isoenzyme among all
Regan ALP
Chemical Inhibited by Phenylalanine
Regan
Intestinal
Placental
Chemically Inhibited by 3M Urea
Bone
Chemically inhibited by Levamisole
Liver
Bone
Highest Elevation of ALP seen in Bone Disorders
Paget’s Disease (Osteitis deformans)
Increased ALP can be seen in:
Osteoblastic acitivity
Kids Growth
Adults > 50 y.o.
Pregnancy (16-20 weeks)
Reference method for ALP Determination
Bowers and McComb
Substrate used in Bessy Lowry and Brock & Bowers and McComb
p-nirophenyl phoshatase
Enzyme used for rape cases
ACP
Major source of ACP
Prostate
ACP is most significant in ______________
Prostatic Carcinoma
ACP is also increased in:
- ________________
- ________________
Gaucher Disease
Nieman’s Pick Disease
Electrophoretic Separation of ACP source which remains in tge ORIGIN
Erythrocytic (RBC)
Electrophoretic separation of ACP sources that have greter MOBILITY
Prostatic
Prostate ACP is inhibited by ___________
L-tartrate
Inhibited by 2% formaldehyde and Cupric Sulfate solution
Erythrocytic
Specific substrate for ALP
p-nitrophenyl phosphate (pnp)
Specific substrate for ACP
Thymolphthalein monophosphate
Substrate used in ACP for continuous monitoring
a-naphthol phosphate
Isoenzymes of AMYLASE
Salivary - Ptyalin
Pancreatic - Amylopectin
Used for EARLY DETECTION of PANCREATITIS (Acute) or a screening test for Acute Pancreatitis
Amylase
Most specific for Pancreatitis
Lipase
Referemce Method for Lipase Determination
Cherry Crandal
Substrate used in Lipase Determination
Olive Oil
NBS marker
G6PD
GGT is sensitive marker for ________________ and _____________
Occult Alcoholism
Acute Alcoholic Hepatitis
Biliary Obstruction
Increase - ALP, GGT
Pseudocholinesterase is a marker for _______________
Insectecide/Pesticide Poisoning
Marker for Wilson’s Disease
Ceruloplasmin