_________________________________________________________________________________________

biochemistry___________________________________________________________________________
Made by: Princess Ann R. Sebello (Block C- BSN 1

ENZYME
- Enzymes are remarkable molecules found in living organisms that play a crucial role in various biological
processes. They act as tiny catalysts, facilitating chemical reactions in our bodies.
- help us to break down food, convert nutrients into energy, and build and repair tissues.
- organic catalysts in the body.
- protein speed up chemical reactions.

 What are enzymes?

1. Enzymes are found in all living cells.

2. Enzymes are made of protein.
3. Enzymes are Biological Catalysts
4. Enzymes speed up reactions
5. Enzymes are unchanged by the reaction

 ENZYME NOMENCLATURE
- According to the name of substrate with the addition of the suffix "ase" (ex. Protease & Lipase)
- According to the type of reaction they catalyze. (ex. Kinase & Dehydrogenase)
- According to the numerical designation given by the Enzyme Commission

Protease – enzyme acting on protein

Lipase – enzyme acting on lipids (1.27)
Lactase – splits lactose into glucose and galactose
Nuclease – breaks down nucleic acids

 Type of Reaction of Enzyme

Kinase – transfer phosphate compound to other

Dehydrogenase – removal of hydrogen atoms from substrate

 CLASSIFICATION OF ENZYMES

1. Oxidoreductase – reduction, deduction, change of electrons. (oxidation reduction)

2. Transferases – they transfer chemical glute to one substrate to another. (transfer)
3. Hydrolases – use water to break a chemical bond
4. Lyses – process of breaking down a cell’s membrane.
- remove the groups from the substrate without hydrolysis, leaving only double bonds in the molecules.
5. Isomerases – convert molecules from one isomer to another.
- catalyzed the intramolecular rearrangement of the substrate compound.
Oxidoreductase
 1. Oxidases – uses oxygen as electron acceptor to catalyze oxidation reaction.
Cytochrome Oxidase
2. Dehydrogenases
LDH – Lactate Dehydrogenate
ML – Malate Dehydrogenate
ICD – Isocitiate Dehydrogenate

Transferases
AST – Aspartate Transaminase
ALT – Alanine Transaminase
CK/CPK – Creatine Kinase / Creatine Phosphokinase
GGT – Gamma-Glutamyl Transferase
OCT – Ornithine Carbamoyl Transferase

Hydrolases

Esterases – Acid Phosphatase (ACP), Alkaline Phosphatase (ALP), Lipase Phosphatase (LPS), Cholinesterase (CNS)
Peptidases – Tripism (PTS), Pepsin (PPS), Leucine Amino (LAP)
Glucosidase – (AMS), Amylo-1, 6-Glucosidase, Galactosidase

Lyases

Aldolases
Glutamate Decarboxylase
Pyruvate Decarboxylase
Tryptophan Decarboxylase

Isomerases

Glucose Phosphate Isomerase

Ribose Phosphate Isomerase

 TERMS ASSOCIATED WITH ENZYMES

Co-factor- non-protein substances, helps enzymes to do activities.

1. Haloenzymes - substances form by the combination of Apo Enzymes and Co-enzymes.

2. Apo Enzymes - protein portion subject to denaturation.

3. Co-enzymes - organic molecule dialyzable of haloenzymes.

Ex. NAD, NADP, Vitamins ( Nicotamide Adenine Dinuclectide Phosphate )

4. Activator - inorganic ions (modify reactions catalyze)

Substrate – a substance upon by enzymes which are specific for each of their particular enzymes.
1. Isoenzymes- present in an individual similar enzymatic activity characteristics

2. Metalloenzymes- metal ions are part of the molecules

3. Proenzymes- reactivate (zymogens)

 ENZYME ASSAY

A. PHOSPHATASES (chemicalize)

- are characterized by their ability to hydrolyze a large variety of organic phosphate enter with the formation of an
alcohol and a phosphate ion.

Two Main Types:

1. ALP - Alkaline Phosphate/ Alkaline Orthophosphoric Monoester Phosphohydrolase
2. ACP - Acid Phosphatase / Acid Orthophosphoric Monoester Phosphohydrolase

ALP – very useful in recognition of Bone diseases.

 Osteitis Deformation - chronic condition of breakdown and growth of bones are increased (affected bone is
pelvic girdle).
 Hyperparathyroidism - to much activity in the hyperparathyriod.
 Bone Neoplasm - abnormal growth of cell in the bones/ abnormal cell “bone tumor”

Isoenzyme:
 Liver - most rapidly moving enzymes
 Bone - most sustainable to heat in activation/ regulates bones mineralization
 Intestine - slowest mowing isoenzymes
 Placenta - increased ALP during first & second trimester of pregnancy

Clinical Significance:
 Increase hepatobilary disease
Ex. Intrahepatic Obstruction – cholestasis
Tuberculosis Granulomas- holemark of tuberculosis
Tumor Metastasis
 Bone disease with osteoblastic activity
Ex. Osteoblastic Tumor-
Rickets - softening and weakening of the bones of the children.
Osteomalacia - softening and weakening of the bones of the adults.
 Moderate elevation
Ex. Hodgkin Disease – leap tissue, growth of the spleen and liver.
CHF - Chronic Heart Failure
Regional Enteritis - “Gohnsase Zymogens” inflamed the small intestine and colon (inflammatory bowel
disease)
Ulcerative Colitis- form of IBD
 Decreased in hypophosphatasia and malnutrition
NV: 20-90 IU/L at 30’C (p-nitrophenyl-phosphate) or 20-90 U/L at 30’C
 ACP – present in prostate glands, red blood cells, liver, spleen, and bone marrow
- richest source of ACP is
Inhibitors:
 L- tartrate – only inhibits the prostatic prostate
 Formaldehyde and Cupric ions- inhibits red blood cells

PH: 4.9 – 5.0

Clinical Significance:
 Highest elevation are seen in metastasizing carcinoma of the prostrate
 Moderate elevation of the total ACP
Ex. Female Breast CA
Paget’s Disease – chronic disorder (long-lasting) / the bone grow larger and become weak (1 or 2 bones)
 Non-prostatic ACP elevation
Ex. Nieman Pick Disease
Gaucher's Disease
Myelocytic Leukemia- type of cancer. Too much abnormal of blood cells
 Presence in seminal fluid- use to inspect for fluids in sexually abuse cases.

NV: 0.13-0.63 U/L at 37°C (p-nitrophenyl phosphate) or 22-10.5 U/L at37 'C

Reference Ranges for ACP:

 Total ACP: Male-2.5-11.7 U/L; Female 0.3-9.2 U/L
 Prostatic ACP: Male-0.2-5.0 U/L; Female 0.2-0.8 U/L

B. AMS / AMYLASE / DIASTASE / ALPHA-1; 4-GLUCAN; 4-GLUCANOHYDROLASE

- split complex CHO like starch and glycogen via hydrolysis to form maltose and maltodextrin
- clinically responsible for digestions of salivary amylase and ptyalin.

Isoenzymes:
 Salivary amylase / ptyalin-
 Pancreatic amylase / amylopsin

Clinical significance:
 Acute pancreatitis
 Elevated levels
ex. Mumps
Perforated Peptic Ulcers
Appendicitis
Raptured Ectopic Pregnancy- the fertilized egg is outside the uterus. The fallopian tubes is burst.
Biliary Tract Disease

NV: 60-160 somogyi units / dl or 111-296 U/L

Reference Ranges for AMS:

 Serum: 60-180 su/dl or 95-290 U/L
  Urine: 35-400 U/L

C. LIPASE / TRIACYL GLYCEROL ACELHYDROLASE (LPS)

- it catalyze the hydrolysis of esters in the alpha position of triglycerol to yields beta monoglycerides and FA
- present mainly in pancreas and other tissue of stomach and intestine.
- can be seen in acute pancreatitis.

PH: 7.8 – 8
Isoenzymes:
 Pancreatic
 Arterial
 Gastric
 Sublingual Lipase

NV: 1.0-1.5 cherry Crandall units

Clinical Significance:
 In acute pancreatitis, LPS becomes more elevated within the 1st 12hours and remain for several days
 Also elevated in pancreatic duct obstruction, and tumor of the pancreas

 PRINCIPLE OF LIPASE
- the major source of lipase is the pancreas. When food enters to the small intestine, it is mixed with a large
number of materials released by the pancreas and gall bladder. Bile salts (synthesized by the liver and stored in
the gall bladder) mix with the food and neutralized the acid present (HCl from the stomach). Then lipase breaks
down the triglycerides into smaller components which can be absorbed across the small intestine. After these
metabolic products cross the intestinal wall, they are then synthesized into TAG and transported to cell where
the fats are stored until needed.

D. AMINOTRANSFERASES

PH: 7.4

Isoenzymes:
 Aspartate Aminotransferase (AST) / Glutamate Oxaloacrtate Transaminase (SGOT)
- Liver and Heart
- An enzyme belonging to the class of transferase. It is commonly referred as transaminase and is involved in the
transfer of amino group between aspartate and alphaketo acids.

 Alanine Aminotransferase (ALT) / Glutamine Pyruvate Transaminase (SGPT)

- A transferase with enzymatic activity similar to AST. Specially, it catalyzes the transfer of an amino group from
alanine to alpha-ketoglutarate with the formation of glutamate and pyruvate.

AST - found in cardiac muscle, skeletal muscle, liver, red blood cell and other tissue like kidney and pancreas.
Clinical Significance:
 MI (Myocardial Infraction) - one of the early enzymes that rise in serum level of AST. “heart attack”

AST levels are usually 4-10x the upper limit of the NV. 4-6H after the onset of pain and peak on the 24th normalized on
the 4th-5th days. These develop within 36thH. These usually

 Increased level also seen in the ff:

Ex. Pulmonary Infraction- lung infraction
Pericarditis
Acute Hepatitis
Skeletal Muscle
 Used to dx of chronic abuse and hepatoxicity
 Decreased in pregnant women

NV: 5 U/L at 37'C

ALT- mostly in liver / To diagnose heart and liver disease

Clinical Significance:
 Acute or chronic viral hepatitis
 MI
 Hepatocellular disease
NV: 6-37 U/L at 37'C

E. LACTATE DEHYDROGENASE (LPH)

- an enzyme that catalyzes the interconversion of lactic and pyruvic acids. It is hydrogen transfer enzymes that use
the co- enzyme NAD.

Tissue Sources:
- LD is widely distributed in the body. Very high activities are found in the heart, liver, skeletal muscle, kidney, and
erythrocytes. It is present in lesser amounts in the lungs, mouth, muscle and brain.

Isoenzymes:
 LDH1 (HHHH) - RBC, heart, kidney
 LDH2 (HHHM) - heart
 LDH3 (HHMM) - WBC, brain, lungs
 LDH4 (HMMM) - tissues, skeletal muscles, liver
 LDH5 (MMMM)
Optimum Ph:
 Forward rxn (lactate-pyruvate): 8.8 - 9.8
 Backward rxn (pyruvate-lactate): 7.4 - 7.8

Clinical Significance:
 Myocardium Infraction- within 8-12 hours (40-60) remains elevated within 14 days
 Also increase in the ff:
Ex. Liver Disease
Muscle trauma
 Hemolytic disease
Pernicious anemia

 Moderate to markedly elevated

Ex. Megaloblastic Anemia
Pulmonary Infraction
Granulocytic leukemia
Hemalytic Anemia
Infectious Mononucleosis (IM)

NV :
 Forward rxn : 100 – 225 U/L at 37’C
 Backward rxn : 80 – 280 U/L at 37’C

F. CREATINE KINASE (CK) / ATP-CREATINE-N-PHOSPHOTRANSFERASE

- promotes the interconversion of creatine and ATP to creatine phosphate and ADP, finishing biochemical energy
for muscle contraction.
- Mucle/cardiac
- 4 to 6 hours onsite (18-30 hours) 3rd day normal

CK – the most specific indecaror for myocardiac

Tissue Sources:
- widely distributed in tissues, with highest activities found in skeletal muscle, heart muscle and brain. Other
sources in smaller quantities include the bladder, placenta, gastrointestinal tract, thyroid, uterus, kidney, lungs,
prostate, spleen, liver and pancreas.
Isoenzymes :
 CK1 (BB)
 CK2 (MB)
 CK3 (MM)
Optimum pH :
 Forward rxn : 9.0
 Backward rxn : 6.8
Clinical Significance :
 Myocardial Infraction ‘
 Increased level
NV : Male : 15 – 16 U/L at 37/C
Female : 15 – 130 U/L at 37/C

Progressive Muscular Dystrophy – genes / muscle dunction

Polymyositis - weakness of the limb and neck muscle
Acute Psychosis - mentally disorder
Alcoholic Myopathy - heavy alcohol consumption
Delirium Tremens - severe form of alcohol wedrawal / sudden and severe mental disorder
Hypothyroidism -
Malignant Hyperthermia - high body temp
Trichinosis - parasite in muscle
Dermatomycosis - infection in skin
Acute Cerebrovascular Disease - stroke

G. FRUCTOSE DIPHOSPHATE ALDOLASE/ALD

- catalyze the splitting of D-fructose diphosphate to D- glyceraldehyde phosphate and dihydroxy acetone
phosphate.
- Fructose found in all cell
- Essential enzyme for glyceraldehyde
- Liver, kidney, brain tissue

PH : 6.8 – 7.2
Isoenzymes:
 Aldolase A
 Aldolase B
 Aldolase C

 Major Enzymes with Clinical Significance

Enzymes Clinical Significance

ACP Prostatic Carcinoma
ALT Hepatic Disorders
ALP Hepatic and Bone Disorders
AMS Acute Pancreatitis
AST Hepatic, Skeletal/Muscle Disorders
CK Myocardial Infraction (MI)
LDH MI, Carcinomas, Hepatic Disorders
LPS Acute Pancreatitis

 SUMMARY

Myocardial Infraction
- CK - MB followed by CK - MM
- AST
- LDH

Hepatic Disease
- AST
- ALT
- LDH
- ALP

Muscle Disorders
- AST - CK ALD

Acute Pancreatitis
- High in amylase and lipase