- Amylase, lipase, proteases added to laundry detergents
- Papain, bromelain added to meat tenderizers
- Lysozyme added to wound dressings
Diagnostic:
- Measuring enzyme levels in blood/urine to detect organ damage
- Measuring enzyme levels in blood to diagnose genetic disorders
Therapeutic:
- Enzyme replacement therapy for genetic disorders
- Enzymes as digestive aids or supplements
Research:
- Enzymes used as reagents in clinical assays and diagnostic kits
So in summary, enzymes play important roles in diagnostics, research, and therapeutics in medicine. Their catalytic properties are exploited for various applications.
Enzymalogy Factors affecting enzyme activity and kineticsrohini sane
A comprehensive presentation on Factors affecting enzyme activity & Kinetics of Enzymes for MBBS ,BDS, B Pharm & Biotechnology students to facilitate self- study.
Many enzymes exist as inactive forms known as zymogens or Proenzymes • proenzymes are synthesized as inactive precursors that are subsequently activated by cleavage of one or a few specific peptide bonds. • a energy source (ATP) is not needed for cleavage. contrast with reversible regulation by phosphorylation, even proteins located outside cells can be activated by this means. • Proteolytic activation, in contrast with allosteric control and reversible covalent modification, occurs just once in the life of an enzyme molecule i.e. the process is irreversible.
Mechanism of action of Chymotrypsin & Lysozyme.pptxVanshikaVarshney5
Chymotrypsin and Lysozyme are the most important enzymes. Mechanism of action of these enzymes and introduction of these enzyme are given in this presentation in simple, easy and understanding language. Hope you will find it useful :)
Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells. They are vital for life and serve a wide range of important functions in the body, such as aiding in digestion and metabolism
Enzymes are dynamic proteins that accelerate biochemical reactions.
Each enzyme acts on a specific reactant, the substrate.
Enzymes are characterized by greater activity, specificity and susceptibility to the influence of pH, temperature and other environmental changes.
Enzymes act in the presence of non-peptide cofactors or coenzymes.
An enzyme lacking its cofactor is called apoenzyme and the active enzyme with its co-factor, the holoenzyme.
This ppt describes the overview of enzyme regulation and Allosterism. Presented since October 23,2017GC at Addis Ababa University, School of Medicine, Department of medical biochemistry.
Diagnostic enzymology
Enzymes are normally intracellular and LOW concentration in blood
Enzyme release (leakage)in the blood indicates cell damage (cell –death, hypoxia, intracellular toxicity)
Quantitative measure of cell/tissue damage
Organ specificity- but not absolute specificity inspite of same gene content.
Most enzymes are present in most cells-differing amounts
Enzymalogy Factors affecting enzyme activity and kineticsrohini sane
A comprehensive presentation on Factors affecting enzyme activity & Kinetics of Enzymes for MBBS ,BDS, B Pharm & Biotechnology students to facilitate self- study.
Many enzymes exist as inactive forms known as zymogens or Proenzymes • proenzymes are synthesized as inactive precursors that are subsequently activated by cleavage of one or a few specific peptide bonds. • a energy source (ATP) is not needed for cleavage. contrast with reversible regulation by phosphorylation, even proteins located outside cells can be activated by this means. • Proteolytic activation, in contrast with allosteric control and reversible covalent modification, occurs just once in the life of an enzyme molecule i.e. the process is irreversible.
Mechanism of action of Chymotrypsin & Lysozyme.pptxVanshikaVarshney5
Chymotrypsin and Lysozyme are the most important enzymes. Mechanism of action of these enzymes and introduction of these enzyme are given in this presentation in simple, easy and understanding language. Hope you will find it useful :)
Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells. They are vital for life and serve a wide range of important functions in the body, such as aiding in digestion and metabolism
Enzymes are dynamic proteins that accelerate biochemical reactions.
Each enzyme acts on a specific reactant, the substrate.
Enzymes are characterized by greater activity, specificity and susceptibility to the influence of pH, temperature and other environmental changes.
Enzymes act in the presence of non-peptide cofactors or coenzymes.
An enzyme lacking its cofactor is called apoenzyme and the active enzyme with its co-factor, the holoenzyme.
This ppt describes the overview of enzyme regulation and Allosterism. Presented since October 23,2017GC at Addis Ababa University, School of Medicine, Department of medical biochemistry.
Diagnostic enzymology
Enzymes are normally intracellular and LOW concentration in blood
Enzyme release (leakage)in the blood indicates cell damage (cell –death, hypoxia, intracellular toxicity)
Quantitative measure of cell/tissue damage
Organ specificity- but not absolute specificity inspite of same gene content.
Most enzymes are present in most cells-differing amounts
Clinical Chemistry Apparatus and Equipmentsjohnsonhce
LABMATETM offer benefits such as advanced semi-automated clinical chemistry coagulation analyzers, economical, user-friendly systems with high performance and low maintenance.
A comprehensive presentation on Enzymology :Types of Enzyme inhibition & Therapeutic uses for MBBS ,BDS, B Pharm & Biotechnology students to facilitate self- study.
21.1 General Characteristics of Enzymes
21.2 Enzyme Structure
21.3 Nomenclature and Classification of Enzymes
21.4 Models of Enzyme Action
21.5 Enzyme Specificity
21.6 Factors That Affect Enzyme Activity
21.7. Extremozymes
21.8 Enzyme Inhibition
21.9 Regulation of Enzyme Activity
21.10 Prescription Drugs That Inhibit Enzyme Activity
21.11 Medical Uses of Enzymes
21.12 General Characteristics of Vitamins
21.13 Water-Soluble Vitamins: Vitamin C
21.14 Water-Soluble Vitamins: The B Vitamins
21.15 Fat-Soluble Vitamins
Clinical chemistry review sheet for mlt certification and ascpDonna Kim
This is a fairly thorough without being bogged down with unnecessary detail study guide for Medical Laboratory Technician studying for the review and state exams
Acid Base
Carbohydrates
Lipids
Proteins
Amino Acids
Enzymology clinical significance of enzymes and isoenzymesrohini sane
A comprehensive presentation on Enzymology Clinical significance of Enzymes & Isoenzymes for MBBS , BDS, B Pharm & Biotechnology students to facilitate self- study.
A comprehensive coverage of Enzymes including basics, mechanisms of enzyme catalysis, enzyme inhibition and clinical applications, mostly based on Stryer- Biochemistry. The slides were intended for MBBS teaching, but should benefit the students of Biochemistry and allied sciences.
Prepared in Sept 2015
Enzymes mechanism of action, their specificity types, active center structure and action, inhibitor types, fisher and Koshlend theory are presented. Enzymes classification, a new class of enzymes discovered recently, detailed explanation of each class reaction types is presented as well
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Top Questions
What is an enzyme?
What are enzymes composed of?
What are examples of enzymes?
What factors affect enzyme activity?
Summary
Read a brief summary of this topic
Enzyme, a substance that acts as a catalyst in living organisms, regulating the rate at which chemical reactions proceed without itself being altered in the process.
In the induced-fit theory of enzyme-substrate binding, a substrate approaches the surface of an enzyme (step 1 in box A, B, C) and causes a change in the enzyme shape that results in the correct alignment of the catalytic groups (triangles A and B; circles C and D represent substrate-binding groups on the enzyme that are essential for catalytic activity). The catalytic groups react with the substrate to form products (step 2). The products then separate from the enzyme, freeing it to repeat the sequence (step 3). Boxes D and E represent examples of molecules that are too large or too small for proper catalytic alignment. Boxes F and G demonstrate binding of an inhibitor molecule (I and I′) to an allosteric site, thereby preventing interaction of the enzyme with the substrate. Box H illustrates binding of an allosteric activator (X), a nonsubstrate molecule capable of reacting with the enzyme.
enzyme
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Category: Science & Tech
Key People: Richard Henderson Emil Fischer Maud Leonora Menten Günter Blobel Arieh Warshel
Related Topics: neuraminidase renin-angiotensin system allosteric control induction cooperativity
A brief treatment of enzymes follows. For full treatment, see protein: Enzymes.
The biological processes that occur within all living organisms are chemical reactions, and most are regulated by enzymes. Without enzymes, many of these reactions would not take place at a perceptible rate. Enzymes catalyze all aspects of cell metabolism. This includes the digestion of food, in which large nutrient molecules (such as proteins, carbohydrates, and fats) are broken down into smaller molecules; the conservation and transformation of chemical energy; and the construction of cellular macromolecules from smaller precursors. Many inherited human diseases, such as albinism and phenylketonuria, result from a deficiency of a particular enzyme.
rennet in cheese making
rennet in cheese making
Rennet, which contains the protease enzyme chymosin, being added to milk during cheese making.
Enzymes also have valuable industrial and medical applications. The fermenting of wine, leavening of bread, curdling of cheese, and brewing of beer have been practiced from earliest times, but not until the 19th century were these reactions understood to be the result of the catalytic activity of enzymes. Since then, enzymes han
Catalysts are something that speeds up the chemical reaction. Almost all biochemical reactions require catalysts.
Enzymes are biocatalysts. Biochemical catalysts speed up the biochemical reactions.
In presence of an enzyme, less energy is required for the reaction to take place.
A catalyst may be defined as a substance that increases the velocity or rate of chemical reactions without itself undergoing any change in the overall process.
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Sustainability has become an increasingly critical topic as the world recognizes the need to protect our planet and its resources for future generations. Sustainability means meeting our current needs without compromising the ability of future generations to meet theirs. It involves long-term planning and consideration of the consequences of our actions. The goal is to create strategies that ensure the long-term viability of People, Planet, and Profit.
Leading companies such as Nike, Toyota, and Siemens are prioritizing sustainable innovation in their business models, setting an example for others to follow. In this Sustainability training presentation, you will learn key concepts, principles, and practices of sustainability applicable across industries. This training aims to create awareness and educate employees, senior executives, consultants, and other key stakeholders, including investors, policymakers, and supply chain partners, on the importance and implementation of sustainability.
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1. Introduction and Key Concepts of Sustainability
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2. ENZYMES
- A protein with catalytic properties due to its
power of specific activation
3. Characteristics of Enzymes
1) biological catalysts
2) not consumed during a chemical reaction
3) speed up reactions from 1000 - 1017, with a mean
increase in rate of 00,000
4) exhibit stereospecificity --> act on a single
stereoisomer of a substrate
5) exhibit reaction specificity --> no waste or side
reactions
4. Classification of Enzyme
Specificity
a. Absolute specificity: substrate
Succinic dehydrogenase- succinic acid to fumaric
acid
b. Linkage specificity:reaction that break bonds
Thrombin- acids arginine and glycine
c. Reaction specificity: reactions
Esterases- hydrolysis of esters
d. Group Specificity: compounds
chymotrypsin- catalyzes only protein that contains
phenylalanine, tryptophan and tyrosine
5. Classification of Enzymes:
1. According to its composition:
a. Simple enzymes-
b. Complex enzymes
holoenzyme - a complete, catalytically
active enzyme including all co-factors
apoenzyme - the protein portion of a
holoenzyme minus the co-factors
prosthetic group - a metal or other co-
enzyme covalently bound to an
6. 2. Class of organic chemical reaction catalyzed:
a. Oxidoreductase - catalyze redox reactions
*dehydrogenases, oxidases, peroxidases, reductases
Dehydrogenase-catalyze the removal of H from
a substrate
Oxidases- activate oxygen so that it will readily c
ombine with a substrate
b. Transferases - catalyze group transfer reactions;
often require coenzymes
7. c. Hydrolases - catalyze hydrolysis reactions
Carbohydrates
1. ptyalin- salivary amylase
-catalyze the hydrolysis of starch to dextrin
and maltose
2. sucrase- hydrolysis of sucrose to glucosE and
fructose
- intestinal juices
3. maltase- hydrolysis of maltose to glucose
4. Lactase- hydrolysis of lactose to glucose and
galactose
8. 5. amylopsin- pancreatic amylase
- hydrolysis of starch to dextrins and
maltose *from pancreas to
Sintestine*
Esters- catalyze the hydrolysis of esters into acids
and alcohol
1. Gastric lipase- hydrolysis of fats to fatty
acids and alcohol
- part of the gastric juices
2. Steapsin- ( pancreatic lipase)
- hydrolysis of fats to fatty acids and
9. Proteases- catalyze the hydrolysis of derived
proteins and amino acids
1. pepsin- hydrolysis of protein to
polypeptides
2. trypsin- found in pancreatic
juice
3. chymotrypsin
11. d. Lyases - lysis of substrate; produce contains
double bond
e. Isomerases - catalyze structural changes;
isomerization
f. Ligases - ligation or joining of two substrates
with input of energy, usually from ATP
hydrolysis; often called synthetases or
synthases
12. Chemical reactions
• Chemical reactions need an initial input of
energy = THE ACTIVATION ENERGY
• During this part of the reaction the
molecules are said to be in a
TRANSITION STATE
15. Making Reactions Go Faster
• Increasing the temperature make molecules move
faster
• Biological systems are very sensitive to temperature
changes.
• Enzymes can increase the rate of reactions without
increasing the temperature.
• They do this by lowering the activation energy.
• They create a new reaction pathway “a short cut”
18. ENZYMATIC REACTION
PRINCIPLES
• Biochemically, enzymes are highly specific for their
substrates and generally catalyze only one type of
reaction at rates thousands and millions times higher
than non-enzymatic reactions. Two main principles
to remember about enzymes are 1) they act as
CATALYSTS (they are not consumed in a reaction
and are regenerated to their starting state) and 2)
they INCREASE THE RATE of a reaction
towards equilibrium (ratio of substrate to product),
but they do not determine the overall equilibrium of
a reaction.
19. CATALYSTS
• A catalyst is unaltered during the course of a
reaction and functions in both the forward and
reverse directions. In a chemical reaction, a catalyst
increases the rate at which the reaction reaches
equilibrium, though it does not change the
equilibrium ratio. For a reaction to proceed from
starting material to product, the chemical
transformations of bond-making and bond-breaking
require a minimal threshold amount of energy,
termed activation energy. Generally, a catalyst
serves to lower the activation energy of a particular
reaction.
20. ENZYMATIC REACTION
PRINCIPLES (cont)
• The energy maxima at which the reaction has the
potential for going in either direction is termed the
transition state. In enzyme catalyzed reactions, the
same chemical principles of activation energy and
the free energy changes (∆Go) associated with
catalysts can be applied. Recall that an overall
negative ∆Go indicates a favorable reaction
equilibrium for product formation. As shown in an
enzyme catalyzed reaction, and in the graph, the net
effect of the enzyme is to lower the activation
energy required for product formation.
21. Binding Energy
• The graph of activation energy and free energy changes
for an enzymatic reaction also indicates the role binding
energy plays in the overall process. Due to the high
specificity most enzymes have for a particular substrate,
the binding of the substrate to the enzyme through
weak, non-covalent interactions is energetically
favorable and is termed binding energy. The same
forces important in stabilizing protein conformation
(hydrogen bonding and hydrophobic, ionic and van der
Waals interactions) are also involved in the stable
binding of a substrate to an enzyme.
22. Reaction Rates
• The rate of the reaction is determined by several factors
including:
A. The concentration of substrate
B. Temperature
C. pH.
23. Effect of Temperature
A reaction rate will generally
increase with increasing
Temperature due to increased
kinetic energy in the system until
a maximal velocity is reached.
Above this maximum, the kinetic
energy of the system exceeds the
energy barrier for breaking weak
H-bonds and hydrophobic
interactions, thus leading to
unfolding and denaturation of the
enzyme and a decrease in reaction
rate.
24. Q10 (the temperature coefficient) = the increase in
reaction rate with a 10°C rise in temperature.
For chemical reactions the Q10 = 2 to 3
(the rate of the reaction doubles or triples with every
10°C rise in temperature)
Enzyme-controlled reactions follow this rule as they
are chemical reactions
BUT at high temperatures proteins denature
The optimum temperature for an enzyme controlled
reaction will be a balance between the Q10 and
denaturation.
25. The effect of temperature
Q10 Denaturation
Enzyme
activity
0 10 20 30 40 50
Temperature / °C
26. The effect of temperature
For most enzymes the optimum temperature is
about 30°C
Many are a lot lower, cold water fish will
die at 30°C because their enzymes denature
A few bacteria have enzymes that can withstand
very high temperatures up to 100°C
Most enzymes however are fully denatured at 70°C
27. Effect of pH
Variations in pH can affect a
particular enzyme in many ways,
especially if ionizable amino acid
side chains are involved in binding
of the substrate and/or catalysis.
Extremes of pH can also lead to
denaturation of an enzyme if the
ionization state of amino acid(s)
critical to correct folding are
altered. The effects of pH and
temperature will vary for different
enzymes and must be determined
experimentally.
28. Extreme pH levels will produce denaturation
The structure of the enzyme is changed
The active site is distorted and the substrate
molecules will no longer fit in it
At pH values slightly different from the enzyme’s
optimum value, small changes in the charges of the
enzyme and it’s substrate molecules will occur
This change in ionisation will affect the binding of
the substrate with the active site.
30. Theories on Enzyme Specificity
1. The Lock and Key Hypothesis
2. The Induced Fit Hypothesis
31. The Lock and Key Hypothesis
• Fit between the substrate and the active site of the
enzyme is exact
• Like a key fits into a lock very precisely
• The key is analogous to the enzyme and the
substrate analogous to the lock.
• Temporary structure called the enzyme-substrate
complex formed
• Products have a different shape from the substrate
• Once formed, they are released from the active site
• Leaving it free to become attached to another
substrate
32. S
E
E
E
Enzyme may be
used again
Enzyme-substrate P
complex
P
Reaction coordinate
33. The Induced Fit Hypothesis
• Some proteins can change their shape
(conformation)
• When a substrate combines with an enzyme, it
induces a change in the enzyme’s conformation
• The active site is then moulded into a precise
conformation
• Making the chemical environment suitable for the
reaction
• The bonds of the substrate are stretched to make
the reaction easier (lowers activation energy)
34. The Induced Fit Hypothesis
Hexokinase (a) without (b) with glucose substrate
http://www.biochem.arizona.edu/classes/bioc462/462a/NOTES/ENZYMES/enzyme_mechanism.html
37. Catalytic Mechanisms: Types
• Four types of catalytic mechanisms will be
discussed:
• binding energy catalysis
• general acid-base catalysis
• covalent catalysis
• metal ion catalysis
38. Acid-Base
Catalysis
Many reactions involve the formation of normally unstable, charged
intermediates. These intermediates can be transiently stabilized in an
enzyme active site by interaction of amino acid residues acting as weak
acids (proton donors) or weak bases (proton acceptors). The general
acid and general base forms of the most common and best characterized
amino acids involved in these reactions are shown above.
39. Acid-Base Catalysis (cont)
• The preceding functional groups can potentially serve
as either proton donors or proton acceptors. This is
dependent on many factors including the molecular
nature of the substrate, any co-factors involved, and the
pH of the active site (which would determine the
ionization state of an amino acid side chain). For acid-
base catalysis, histidine is the most versatile amino acid
due to its pKa which means that in most physiological
situations it can act as either a proton donor or proton
acceptor. Generally these amino acids will interact
together with the substrate, or in conjunction with
water or other weak, organic acids and bases found in
cells.
40. Binding Energy Catalysis
• Binding energy accounts for the overall lowering of
activation energy for a reaction, and it can also be
considered as a catalytic mechanism for a reaction. Several
catalytic factors in the binding of a substrate and enzyme
can be considered: 1) transient limiting of substrate and
enzyme movement by reducing the relative motion (or
entropy) of the two molecules, 2) solvation disruption of the
water shell is thermodynamically favorable, and 3) substrate
and enzyme conformational changes. All three of these
factors individually or in combination are utilized to some
degree by an enzyme. While in some instances these forces
alone can account for catalysis, they are frequently
components of a complex catalytic process involving
factors discussed for the other types of catalytic
41. Covalent Catalysis
• This mechanism involves the transient
covalent binding of the substrate to an
amino acid residue in the active site.
Generally this is to the hydroxyl group of a
serine, although the side chains of
threonine, cysteine, histidine, arginine and
lysine can also be involved.
42. Metal Ion Catalysis
• Various metals, all positively charged and
including zinc, iron, magnesium, manganese
and copper, are known to form complexes with
different enzymes or substrates. This metal-
substrate-enzyme complex can aid in the
orientation of the substrate in the active site,
and metals are known to mediate oxidation-
reduction reactions by reversible changes in
their oxidation states (like Fe3+ to Fe2+).
43. Summary of Catalytic
Mechanisms
• In general, more than one type of catalytic
mechanism will occur for a particular enzyme
via various combinations of binding energy,
acid-base, covalent and metal catalysis.
Enzymes as a whole are incredibly diverse in
their structures and the types of reactions that
they catalyze, therefore there is also a large
diversity of catalytic mechanisms utilized, the
basis of which must be determined
experimentally.
44.
45. Inhibitors
• Inhibitors are chemicals that reduce the rate of
enzymic reactions.
• The are usually specific and they work at low
concentrations.
• They block the enzyme but they do not usually
destroy it.
• Many drugs and poisons are inhibitors of
enzymes in the nervous system.
46. The effect of enzyme inhibition
• Irreversible inhibitors: Combine with the
functional groups of the amino acids in the active
site, irreversibly.
Examples: nerve gases and pesticides, containing
organophosphorus, combine with serine residues
in the enzyme acetylcholine esterase.
47. Reversible inhibitors: These can be washed out of
the solution of enzyme by dialysis.
Two Categories:
Competitive: These compete with the substrate
molecules for the active site.
The inhibitor’s action is proportional to its
concentration.
Resembles the substrate’s structure closely.
48. Non-competitive: These are not influenced by
the concentration of the substrate. It inhibits by
binding irreversibly to the enzyme but not at
the active site.
Examples
• Cyanide combines with the Iron in the enzymes
cytochrome oxidase.
• Heavy metals, Ag or Hg, combine with –SH
groups.
T hese can be removed by using a chelating agent
such as EDTA.
49. Medicine inhibitors:
a. Methotrexate in cancer chemotherapy to semi-
selectively inhibit DNA synthesis of malignant
cells
b. Aspirin to inhibit the synthesis of
prostaglandins which are at least partly
responsible for the aches and pains of arthritis
c. Sulfa drugs to inhibit the folic acid synthesis
that is essential for the metabolism and growth of
disease-causing bacteria
50. Activators: are molecules that
increase activity.
Examples:
Lipases- Used to assist in the removal of fatty
and oily stains.
Amylases Detergents- for machine dish washing
to remove resistant starch residues.
Papaine- To soften meat for cooking.
51. Clinical Use of Enzymes
• Enzyme Activity in Body Fluids Reflects Organ
Status:
• Cells die and release intracellular contents;
increased serum activity of an enzyme can be
correlated with quantity or severity of damaged
tissues (ex. creatine kinase levels following heart
attack)
• Increased enzyme synthesis can be induced and
release in serum correlates with degree of
stimulation (ex. alkaline phosphatase activity as a
liver status marker)
52. Clinical Use of Enzymes (cont)
• Enzyme Activity Reflects the Presence of
Inhibitors or Activators
• Activity of serum enzymes decreases in presence
of an inhibitor (ex. some insecticides inhibit serum
cholinesterases)
• Determine co-factor deficiencies (like an essential
vitamin) by enzyme activity (ex. add back vitamin
to assay, if activity increases, suggests deficiency
in that vitamin)
53. Clinical Use of Enzymes (cont)
• Enzyme activity can be altered genetically
• A mutation in an enzyme can alter its substrate
affinity, co-factor binding stability etc. which can be
used as a diagnostic in comparison with normal
enzyme
• Loss of enzyme presence due to genetic mutation as
detected by increased enzyme substrate and/or lack
of product leading to a dysfunction
• NOTE: PCR techniques that identify specific
messenger RNA or DNA sequences are replacing
many traditional enzymatic based markers of
genetic disease
54. Enzymes in the Diagnosis of
Pathology
The measurement of the serum levels of
numerous enzymes has been shown to be of
diagnostic significance. This is because the
presence of these enzymes in the serum
indicates that tissue or cellular damage has
occurred resulting in the release of
intracellular components into the blood .
55. Commonly assayed enzymes :
a.amino transferases:
b. alanine transaminase, ALT (sometimes still
referred to as serum glutamate-pyruvate
aminotransferase, SGPT)
c. aspartate aminotransferase, AST (also referred to
as serum glutamate-oxaloacetate aminotransferase,
SGOT);
d. lactate dehydrogenase, LDH;
e. creatine kinase, CK (also called creatine
phosphokinase, CPK);
f. gamma-glutamyl transpeptidase, GGT.
56. -The typical liver enzymes measured are AST
(aspartate aminotransferase), and
ALT(Alanine transaminase) .
-Normally in liver disease or damage that is
not of viral origin the ratio of ALT/AST is less
than 1. However, with viral hepatitis the ALT/
AST ratio will be greater than 1.
57. The 5 types and their normal distribution and levels in
non-disease/injury are listed below. (lactate
dehydrogenase )
• LDH 1 – Found in heart and red-blood cells and is
17% – 27% of the normal serum total.
• LDH 2 – Found in heart and red-blood cells and is
27% – 37% of the normal serum total.
• LDH 3 – Found in a variety of organs and is 18% –
25% of the normal serum total.
• LDH 4 – Found in a variety of organs and is 3% –
8% of the normal serum total.
• LDH 5 – Found in liver and skeletal muscle and is
0% – 5% of the normal serum total.
58. • CPK( Creatine phosphokinase) is found primarily in
heart and skeletal muscle as well as the brain.
Therefore, measurement of serum CPK levels is a
good diagnostic for injury to these tissues. The levels
of CPK will rise within 6 hours of injury and peak by
around 18 hours. If the injury is not persistent the
level of CK returns to normal within 2–3 days. Like
LDH, there are tissue-specific isozymes of CPK and
there designations are described below.
• CPK3 (CPK-MM) is the predominant isozyme in
muscle and is 100% of the normal serum total.
• CPK2 (CPK-MB) accounts for about 35% of the
CPK activity in cardiac muscle, but less than 5% in
skeletal muscle and is 0% of the normal serum total.
• CPK1 (CPK-BB) is the characteristic isozyme in
brain and is in significant amounts in smooth muscle
and is 0% of the normal serum total.