Biochem Block 1 Questions- Final

Front 1

Prominent features of collagen:

Back 1

Ans: Triple helix, presence of glycine (approx. 1/3rd of the total amino acids), presence of significant amount of proline, hydroxyproline, hydroxylysine and glycine

Front 2

Examples for acidic/basic/aromatic/sulfur containing/ nutritionally essential/amino acids

Back 2

acidic aa- aspartate, glutamate

basic aa- histidine, arginine, lysine

aromatic- phenylalanine, tyrosine, tryptophan

sulfur containing- methionine, cysteine

nutritionally essential aa-MAT VIL PHLY

Front 3

Among the 20 different amino acids, which contains an imino group (or which is an eg for imino acid)?

Back 3

histidine

Front 4

Examples for modified amino acids present in proteins

Back 4

Hydroxyproline
Hydroxylysine
Gamma carboxyglutamate
N-methyl lysine
-->Vitamin C is important for Proline to be converted into hydroxyproline

Vitamin C helps in modification of lysine into hydroxylysine

Collagen is produced by these amino acids if it is properly done

Gamma carboxyglutamate- needs vitamin K important for blood clotting factor

Front 5

Examples for non protein amino acids

Back 5

Beta alanine
Ornithine
Citrulline
Homocysteine
Homoserine
Gamma amino butyric acid
Taurine- Has sulfur

Front 6

Among the amino acids present in proteins, which is optically inactive (no asymmetric carbon atom)?

Back 6

With the exception of glycine, all the amino acids present in proteins exhibit D & L isomerism (enantiomerism/ mirror image isomerism)

Front 7

Learn the definition of pk

Back 7

The tendency of dissociation behavior of different ionizable groups, present in amino acids,can be expressed in terms of pK values.

pK is negative log. of dissociation constant, K.

pK is defined as the pH at which an acid group is half dissociated or in other words, pK is the pH at which both protonated (undissociated) & unprotonated (dissociated) forms of acid group are present at equal concentration.
Based on the pK values it is obvious that among different dissociable groups of amino acids, carboxyl group dissociates earlier and guanidino (guanido) group of arginine dissociates much later.

Since the pK of all the carboxyl groups are much below pH 7.0, and since these carboxyl groups are in dissociated states at neutral pH, they are considered as acidic groups.
On the other hand, pK values of α - amino groups, ε-amino group of lysine and guanido group of arginine are much higher than 7.0. Moreover, these groups exist in fully associated (protonated) form at neutral pH. Hence these groups are called as basic groups.

Front 8

learn the definion of pI

Back 8

The pH at which an amino acid exists in zwitterionic form is called as isoelectric pH (pI)
Each amino acid has an pI value.

pI value indicates whether an given amino acid is acidic, neutral or basic

Front 9

learn the definition of zwitterion

Back 9

If the ionic form of an amino acid contains equal number of +ve and –ve charges, it is called as zwitterionic form.

Front 10

pK values of different ionizable groups of Amino acids

Back 10

pK
α – Carboxyl 2.0 (Approx.)
α - Amino 9.5 (Approx.)
β - Carboxyl (Aspartate) 3.9
γ - Carboxyl (Glutamate) 4.3
ε - Amino (Lysine) 10.5
Guanido (Arginine) 12.5
Imidazole (Histidine) 6.1

Front 11

The two components needed to make a buffer solution

Back 11

Solutions of weak acids and their conjugate bases exhibit the ability to resist pH change when strong acids or bases are added. They are called buffers.

Buffering action is maximum at pK values

Good buffering action is also observed at pH 1.0 unit above and below the pK value.

At physiological pH of body fluids, only imidazole group of histidine can act as buffer.

Front 12

Eg. For short peptides with 2 amino acids of biological importance

Back 12

2-Carnosine: β-alanyl histidine
Anserine: It is N-methyl carnosine

These two peptides are found in muscle.
They activate myosin ATPase activity.
Both are capable of chelating copper and
enhance copper uptake.

Front 13

Eg. For short peptides with 3 amino acids of biological importance

Back 13

3: Glutathione:

It is a tripeptide consisting of glutamate, cysteine & glycine
(Gamma glutamyl cysteinyl glycine).

It is conventionally written as GSH

It is an important component of cellular antioxidant defense system.

It is an essential component, required for integrity of RBC cell membrane.

It participates as cofactor in many reactions.
2 molecules of GSH can donate a pair hydrogen to reduce a substrate


Thyrotropin Releasing Hormone (TRH) :
It is PyroGlu-His-Prolinamide. It is secreted by hypothalamus. It stimulates release of Thyroid stimulating hormone (TSH) from anterior pituitary gland.

Front 14

Eg. For short peptides with 5 amino acids of biological importance

Back 14

Enkephalin:
It is a pentapeptide found in brain.
It inhibits sense of pain

Front 15

Eg. For short peptides with 8 amino acids of biological importance

Back 15

Angiotensin II
A peptide with 8 amino acids
It is a hypertensive agent
It stimulates release of aldosterone from adrenal cortex.

Front 16

Eg. For short peptides with 9 amino acids of biological importance

Back 16

Vasopressin ( antidiuretic hormone):
Secreted by posterior pituitary gland.
It regulates water excretion by kidney

Oxytocin:
Secreted by posterior pituitary gland.
Causes contraction of uterus.
Used in induction of labor

Front 17

A peptide bond is formed by

Back 17

A peptide bond is formed when an amino group of one amino acid reacts with a carboxyl group of another amino acid.

Front 18

The reagent used to determine N-terminal amino acid residue is

Back 18

N- terminal amino acid residue can be identified by using Sanger’s reagent (FDNB) or Dansyl Chloride.

Front 19

The reagent used to determine amino acid sequence is

Back 19

Each of the peptide is separated and its sequence is determined by Edman technique, using the reagent, Phenyl isothiocyanate.

Front 20

What is the defect in primary structure of CFTR in cystic fibrosis?

Back 20

Cystic Fibrosis Transmembrane Regulatory (CFTR) protein (total a.a.1480) functions as a chloride channel in epithelium of several tissues.
In cystic fibrosis (a autosomal recessive disorder) a gene mutation results in lack of a phenyl alanine in CFTR protein. This modification abolishes the chloride and fluid secretary capacity of CFTR protein, thereby resulting in impairment of pancreatic, intestinal and lung functions.

Front 21

Dimensions of alpha-helix

Back 21

Polypeptide chain is coiled around a central axis as right handed helix.
α-carbon, peptide N and carbonyl C form the back bone of the helix.
The side chains of amino acids are projected radially outwards.

α - Helix structure is stabilized by H-bonds. The hydrogen bond is formed between carbonyl oxygen (C=O) of one peptide bond and peptide N of 4th peptide bond in succession. NH and C=O are placed at optimal distance and orientation to form H-bond. Van der Waals interactions also help to stabilize.

Pitch of the helix is 0.54 nm. In each turn there are 3.6 residues, Vertical distance occupied by each amino acids is 0.15 nm.

Front 22

Them amino acids unfavorable for alpha-helix are

Back 22

Since the peptide bond nitrogen of proline lacks a hydrogen atom to contribute to a hydrogen bond, proline can only be stably accommodated within the first turn of an helix.

When present elsewhere, proline disrupts the conformation of the helix, producing a bend.

Because of its small size, glycine also often induces bends in helices.

Front 23

Which type of bond/s is/are responsible for secondary structure of proteins?

Back 23

Maintained by hydrogen bondings

Front 24

The bonds responsible for tertiary structure of proteins are:

Back 24

Tertiary structure of protein is stabilized primarily—and often exclusively—by noncovalent interactions.

Electrostatic bonds between acidic and basic amino acid residues.

H-bonds between polar amino acid residues.

Hydrophobic interaction among non-polar side chains. These interactions drive most hydrophobic amino acid side chains into the interior of the protein, shielding them from water.

Front 25

Quaternary structure of proteins refers to:

Back 25

Refers to the regular association of two or more polypeptide chains to form a single functional protein

Front 26

Eg for quaternary structure of proteins

Back 26

Hemoglobin
Lactate dehydrogenase
Immunoglobulins
Hormone receptors

Front 27

Learn about the denaturation of protein

Back 27

Loss of native structure (conformation) of
proteins is called denaturation.

Secondary, tertiary and quaternary structure of proteins are destroyed during denaturation.

However, primary structure of protein remains unaltered

Except primary structure, other levels of protein structures are destroyed.

Biological activity is lost.

It is irreversible (generally)

Viscosity is increased.

Proteins become insoluble

Digestibility of proteins is increased. In the stomach HCl of gastric juice denatures dietary proteins and make them digestible.

Denatured proteins cannot be crystallized.

Front 28

prion disease

Back 28

The word prion refers to proteinaceous infectious agent.
It causes Prion diseases (transmissible spongiform encephalopathies)
Prion diseases are fatal neurodegenerative diseases, characterized by spongiform changes and neuronal loss, resulting from the deposition of insoluble protein aggregates in neural cells.

Prion diseases can be acquired either through infection (mad cow disease) or inherited mutation eg. Creutzfeldt - Jacob Disease (CJD)

Prions are reported to cause a neurogegenerative disease by triggering misfold of other cellular proteins in such away that they can not be degraded

Prion protein is normally found in brain. It is represented as PrPc,

The disease causing prion protein is represented as PrPsc.
PrPsc has the same amino acid composition as that of normal prion protein PrPc
However, the PrPsc is folded into different conformation compared to PrPc.
PrPc is rich in alpha – helix, but has little or no β-sheat,
On the other hand, PrPsc possesses extensive β-sheat structures.

This extensive β-sheat structures favor aggregation of PrPsc to form multimeric complexes, that are resistant to proteolytic cleavage.

Once formed, PrPsc acts as a template & triggers transformation of other native PrPc proteins, so that the transformed proteins also acquire the misfolded β-sheat structures.

Front 29

Alzheimer’s Disease:

Back 29

It is another neurodegeneraive disease, characterized by progressive memory loss
Another eg. for misfolding of proteins
Accumulation of aggregates of β-amyloid protein in brain tissue
β-amyloid protein is formed from larger protein, called as amyloid precursor.
Transformation of a soluble α - helix rich state to β- sheat rich state.

Front 30

Importance of Chaperone (heat shock protein):

Back 30

Chaperone proteins were discovered as Heat Shock Proteins (hsp), a family of proteins.

The synthesis of these proteins is increased at elevated temperatures.

Chaperones increase the rate of folding by limiting the number of unproductive folding.

Chaperone proteins are also required for refolding of proteins after they cross cellular membrane.

A type of chaperones, called as Chaperonins have an ATPase activity and hydrolyze ATP to facilitate folding

Front 31

Different methods, used to determine the quantity of proteins in different biological samples, along with their merit and demerits (if any):

Back 31

1. Biuret Method;
Most accurate but requires large sample due to lack of sensitivity.

2. Lowry’s method;
Reagent used – Folin-Ciocalteau phenol.
Sensitive for proteins. Bluish color is developed with proteins. However, the intensity of the color depends on tyrosine & tryptophan content of the proteins.
This method is used in protein research.

Front 32

Different methods, used to determine the quantity of proteins in different biological samples, along with their merit and demerits (if any):

Back 32

UV absorption method:
Proteins by virtue of the presence of Tyrosine and Tryptophan can absorb UV light at 280 nm. This facilitates estimation of protein in a given sample using spectrophotometer.
The protein sample should be clear and colorless.
Other Quantitative methods:
Dye binding method (eg. Bromocresol green for the estimation of Serum albumin)
Nephelometry
Turbidometry

Front 33

Application of the technique electrophoresis:

Back 33

It is a separation technique based on charge properties of molecules.
Proteins, by virtue of their net electric charges can be separated by electrophoretic techniques.
-- Agar gel electrophoresis
-- Ployacrylamide gel electrophoresis(PAGE)
On electrophoresis, the separated protein bands can be identified by using specific stains or dyes

Front 34

Different types of protein (polypeptide) chains present in different types of Hb (hemoglobin) are:

Back 34

Adult hemoglobin (HbA) contains 2 α- chains and 2 β-chains.

Fetal Hb (HbF) contains 2α and 2γ chains

A minor form in adult is HbA2 (2α and 2δ)

Front 35

Which amino acid, present in alpha-helical segments of Hb molecules, interacts with the heme iron?

Back 35

histidine

Front 36

Significance of T & R forms of Hb:

Back 36

In T-form the network of ionic and H-bonds are stronger and movement is limited. This form has low affinity to oxygen.

R-form has high affinity to oxygen, more freedom of movement for polypeptide chains.

Front 37

Name the factors that affect unloading of oxygen from oxyHb:

Back 37

affected by
Partial pressure of O2, pH, partial pressure of CO2 and the presence of 2,3-bisphospho-glycerate. These effects are collectively called allosteric effects.

Front 38

Glycated Hemoglobin:

Back 38

It is represented as HbA1c
Free glucose residues bind to N-terminal a.a. residues of globin chains
The process is called as non- enzymatic glycosylation
Normally 4 – 8% of Hb exists as Hb A1c, but it is elevated in diabetes mellitus
The measurement of HbA1c indicates average glucose conc. in plasma over a period of time (approx. past 2 months).

Front 39

Sickle cell disease / Sickle cell anemia

Back 39

Is an autosomal recessive disorder.

Life long episodes of pain, hemolytic anemia, increased susceptibility to infections.

Here, at 6th position of β-chain glutamate is replaced by valine

Electrophoresis of hemoglobin at alkaline pH, HbS moves slower to anode compared to HbA.

Substitution of non polar valine in the place of glutamate forms a sticky patch on Hb S. Because of this, in the doxygenated state, Hb S molecules polymerize into long fibrous aggregate distorting the shape of the red cells


Distorted erythrocytes block capillaries, results in tissue anoxia causes pain and death of cells.
The extent of severity is enhanced by high altitude, increase in Pco2, decrease in pH.

Heterozygous state is called sickle cell trait. Heterozygous individuals contain both Hb A & S in their RBC. They generally do not show clinical symptoms. However, they have the natural tendency of resistance to malaria

Front 40

Hemoglobin C disease

Back 40

It is a mild disease, with chronic hemolytic anemia.

HbC is a variant that has lysine substituting glutamate at 6th position of β-globin chain.

HbC moves slower than HbS during electrophoresis.

Front 41

Methemoglobinemia

Back 41

Oxidation of Fe2+ of heme to Fe3+ results in the formation of methemoglobin, that fails to bind oxygen.

Oxidation may be caused by compounds such as nitrates, reactive oxygen species
It may be also caused due to gene mutation, which results in amino acid replacements – leads to the formation of Hb M

α-58 His Tyr (HbM Boston)
β-92 His Tyr (HbM Hyde park)

Front 42

α-Thalassemias:

Back 42

Synthesis of α-chain is decreased or absent.

Each individual has 2 pairs of α-globin gene. If one gene is defective the individual is silent carrier of thalassemia.

If 2 genes are defective, the person has α-thalassemia trait.

Defect in 3 α-globin genes leads to hemoglobin H disease. The subjects suffer from moderate to severe hemolytic anemia. β-tetramers accumulate in RBC. It has high affinity for oxygen.

Defect in all four α-globin genes causes fetal death (Hydrops fetalis).

Front 43

β-Thalassemias

Back 43

Synthesis of β-globin chains is decreased or absent.
HbF (α2 γ2) and γ4 (Hb barts) may occur in these cases.
There are two copies of genes for β-globin synthesis.
If only one gene is defective it is called thalassemia minor.

Front 44

Beta thalassemia major

Back 44

Defect in both genes causes β-thalassemia major. Physical manifestation occur after birth.

Infants become severely anemic after birth, in the first or second year. They require regular transfusions of blood.

Front 45

Prominent features of collagen:

Back 45

(Ans: Triple helix, presence of glycine (approx. 1/3rd of the total amino acids), presence of significant amount of proline, hydroxyproline, hydroxylysine and glycine

Front 46

Study the defects of Ehlers-Danlos syndrome and Osteogenesis imperfect:

Back 46

Ehlers-Danlos syndrome: stretchy skin and loose joints with poor strength of connective tissue is due to a defect in collagen processing.

Osteogenesis imperfecta or brittle bone syndrome is a group of disorder with brittle bone, poor healing of wounds, twisted spine.

Front 47

Normal values for serum total proteins, albumin, globulin and A/G ratio:

Back 47

Total serum protein 6-8 g/dl

Albumin 3.5-5 g/dl

Globulins 2.2-3.5 g/dl

Normal A/G ratio – Approx. 2:1

Front 48

Functions of plasma (serum) albumin:

Back 48

Carrier for bilirubin, free fatty acid, copper, thyroxin, ASA; it’s a buffer; regulates blood volume

Front 49

The compounds, which are transported by plasma albumin, are:

Back 49

Transports free fatty acids, bilirubin, calcium, copper, thyroxine, steroid hormones, (drugs such as aspirin, penicillin, sulfonamides).

Front 50

Decreased serum albumin level is seen in:

Back 50

Low albumin level is seen in diseases such as
cirrhosis of liver ( chronic)
malnutrition,
malabsorption syndrome,
nephrotic syndrome

Front 51

One of the symptoms seen, due to the hypoalbuminemia (decrease in serum albumin level) is:

Back 51

Hypoalbuminemia is associated with edema.

Front 52

Examples for alpha-1 globulins in serum:

Back 52

α1- Antitrypsin (α1- Antiproteinase)

Inhibits proteolytic actions of trypsin,
elastase, chymotypsin. Accounts for major
antiproteolytic activity of plasma.

It protects the elastic tissues of the lung from destructive action of elastase

4. Inherited deficiency is associated with emphysema and cirrhosis. Incidence is 1 in 1000.

5. In various inflammatory diseases or neoplastic conditions its increased several folds. Thus it is an example for ‘acute phase proteins’.

Front 53

Other α -1 globulins..

Back 53

Retinol binding protein,
Thyroxine binding globulin
High density lipoprotein
α -1 acid glycoprotein

Front 54

What is the role of alpha-1 globulins in serum:

Back 54

Accounts for major
antiproteolytic activity of plasma.

Front 55

What is the role of alpha-1 antitrypsin in lungs?

Back 55

It protects the elastic tissues of the lung from destructive action of elastase

Front 56

Examples for alpha-2 globulins of serum:

Back 56

α-2-Macroglobulin
Haptoglobin
Ceruloplasmin
Transferrin

Front 57

Functions and clinical significance of alpha-2 macroglobulin/ Haptoglobulin/ceruloplasmin/transferring of serum:

Back 57

alpha-2 macroglobulin-- It is a major component of α-2 globulin.
Inactivates all proteinases and important scavenger of proteinases in plasma.
Its concentration is markedly increased in nephrotic syndrome

Haptoglobulin-- It is a tetrameric protein capable of binding hemoglobin.

Immediately cleared upon binding to Hb.

Low level indicates hemolysis.

It is also an acute phase protein

Copper containing α-2 globulin.

90% of copper in plasma is bound to this protein.

Has ferroxidase activity. Helps in iron metabolism by converting ferrous to ferric iron

ceruloplasmin--Decreased ceruloplasmin is associated with Wilson’s disease (hepatolenticular degeneration).

transferrin of serum---A β - globulin.

Transports iron (in ferric form)

Increased in iron deficiency.

Usually 1/3 of its capacity is saturated.

Front 58

Name acute phase proteins:

Back 58

Alpha-1- anti-trypsin,
Haptoglobin,
Ceruloplasmin,
C-reactive protein,
Fibrinogen .

Front 59

Salient features of the structure of immunoglobulin (Ig):

Back 59

They are defense proteins in plasma produced by B-lymphocytes in response to a foreign antigen.

A typical Ig is a tetramer of 2H and 2 L chains.

It forms a Y- shaped structure.

Amino terminal part of L chain and H chain forms the antigen binding site.

Inter chain and intra chain disulphide bonds stabilize the structure.

C-terminal half of the heavy chain forms the Fc segment.

Front 60

IgG

Back 60

Most abundant of the 5 classes (80%of total) 0.8-1.5g/dl.

Can cross blood vessels and placenta.

Its binding triggers foreign cell destruction mediated by complement system

Front 61

IgA

Back 61

Single monomer or a dimer held together by J-chain.

Secreted in saliva, tears, sweat, milk, colostrum, intestinal secretions.

Protects at the epithelial surfaces, prevents entry of pathogens.

Front 62

IgM

Back 62

Largest among the Igs; a pentamer held together by J-chains.

Cannot cross blood vessels, placenta.

First class of antibody formed by B-cells.

Effective against invading micro-organisms.

Front 63

IgD

Back 63

Its conc. is low in circulation.

Present on the surface of B cells.

Functions as B-cell receptor.

Front 64

IgE

Back 64

Single Y-shaped monomer. Present in low concentration in plasma.

Level is elevated in allergic conditions.

IgE-antigen complex bind, trigger mast cells to release histamine and cause allergy.

Front 65

Study the details of multiple myeloma & Bence Jones proteins:

Back 65

Is a plasma cell cancer, accounts for 1% of all cancers. Usually occurs above the age of 45.
Malignancy of a clone of plasma cells in bone marrow.
When serum protein electrophoresis is performed, a sharp band is seen at γ or β regions.
Several cases of multiple myeloma is characterized by the excretion of a unique protein, called as ‘Bence Jones Protein’ in urine. This can be identified by a simple heat test.

Front 66

Study the clinical significance of alpha-1 antitrypsin

Back 66

Protects the lungs form elastase, if deficiency is inherited there is emphysema and cirrhosis.

Front 67

Classification of enzymes with two examples for each class?

Back 67

Oxidoreductase: catalyzes oxidation and reduction reaction
Alcohol Dehydrogenase & Lactate Dehydrogenase
Transferases: catalyzes group transfer reactions
Hexokinase & Alanine Transaminase (ALT)
Hydrolases: catalyzes the hydrolysis of covalent bonds
Lactase: Lactose & Maltase
Lyases: catalyzes the cleavage of covalent bonds
HMG CoA Lyase & Aldolase
Isomerase: Catalyzes the inter-conversion of different types of isomers
Phopho Hexose Isomerase & Phopho Hexose Isomerase
Ligases: Catalyzes the formation of new covalent bonds with expenditure of energy
Acetyl CoA carboxylase & Glutamine synthetase

Front 68

The four general mechanisms of enzyme catalysis?

Back 68

Catalysis by Proximity, Acid-Base Catalysis, Catalysis by Strain, Covalent Catalysis

Front 69

Definition & Importance of Km of enzymes?

Back 69

½ maximal velocity, indicate the affinity between the substrate and the enzyme. Km is the concentration of substrate at half the maximal velocity.

Front 70

Michaeli’s Menten equation?

Back 70

Vi = Vmax+ [S]/ Kmax+ [S]

Front 71

Features of competitive enzyme inhibition?

Back 71

Competitive inhibitors are usually substrate analogues. ie they
resemble the true substrate. Competitive substrate binds at the active
site of the enzyme. A competition exists between the inhibitor and the
true substrate for binding with active site

Front 72

Competitive enzyme inhibitors of clinical importance?

Back 72

Sulfanilamide: antibac/antibiotico
Methotrexate: anti CA agent
Ttimethroprim: antibac
Dicoumarol: se parece al Vit K. asi que se usa como anticoagulante
Statins: reducen el colesterol
6-Mercaptopurine: anti CA agent

Front 73

Features of non competitive enzyme inhibition?

Back 73

Non competitive inhibitors do not have a structural resemblance to substrate; Binds to the region of the enzyme other than active site; Changes the shape of enzyme, resulting in crippled enzyme

Front 74

The enzymes, which are inhibited by DFP, Cyanide & Iodoacetae are?

Back 74

DFP: Inhibits enzyme that contain Serine residue E.g. Trypsin, chymotrypsin, Thrombin, Plasmin, Acetyl Cholinesterase.
Cyanide: inhibit Cytochrome Oxidase (Serine residue)
Iodoacetate: inhibit Cysteine containing residues E.g Glyceraldehyde 3 P. Dehydrogenase

Front 75

Eg for suicide inhibitors & the enzymes inhibited by them?

Back 75

Allopurinol: acts on Xanthine Oxidase, used for gout treatment
DFMO: acts on Ornithine Decarboxylase, used for Sleep Sickness (Trypanosomiasis) treatment
FdUMP: inhibit Thymidylate Synthase, Anti cancer drug
Aspirin: alnalgesico y NSAID

Front 76

Features of allosteric enzymes?

Back 76

processes an active site + one or more additional sites for binding
with effectors or modifiers
effectors may be positive: son estimulantes
effectors may be negative: son inhibidores
when plotted against substrate conc. Sigmoid curve is observed

Front 77

Examples of allosteric enzymes with their allosteric regulators?

Back 77

Phosphofructokinase: ATP & Citrate -> Inhibitors
AMP & Fructose 2, 6 bisPO4 -> Activators
Acetyl CoA Carboxylase: Long Chain Acyl CoA -> Inhibitor
Citrate -> Activator

Front 78

Examples of enzymes that undergo regulation by covalent modifications
(phosphorylation & dephosphorylation)?

Back 78

acetyl CoA carboylase, glycogen synthase, pyruvate dehydrogenase, HMG-CoA reductase, glycogen phosphorylase

Front 79

Learn the isoenzymetic patterns of Lactate dehydrogenase (LDH), Creatine Kinase & Alkaline phosphatase?

Back 79

Lactate dehydrogenase (LDH): Known as LDH,
Tetrameric (4 polypeptide chain),
LDH 1(Heart), 2 (Blood), 3 (Brain), 4(Liver), 5 (Skeletal muscles)
Creatine Kinase: found in heart, brain, skeletal muscles
CK1 or CKBB = Brains & Lungs
CK2 or CKMD = Heart
CK3 or CKMM = Skeletal muscles
Alkaline Phosphatase: Alpha 1 – Biliary Canaculi 10%
Alpha 2 – Hepatic 25% heat labile
Alpha 2 – Placental 1% heat stable
Pre beta Bone 50%
Y Intestine 10%
Leukocyte 4%

Front 80

Eg for functional (plasma specific) enzymes of plasma?

Back 80

Blood clotting enzymes, Plasmin, Lipoprotein, Lipase, Ceruloplasmin (ferroxidase activity)

Front 81

Study the plasma enzymes used in the diagnosis of?

Back 81

Plasma Enzymes Major diagnostic use
Aspartate transaminase (AST) Myocardial infarction (MI)
Alanine transaminase (ALT) Hepatitis
Amylase Acute pancreatitis
Creatine Kinase MI and Muscle disorders
γ- glutamyl transferase Liver & biliary tract disorders
indicador de alcoholismo
Lactate dehydrogenase(isoenzymes) MI and Muscle disorders
Lipase Acute Pancreatitis
Acid phosphatase Prostate cancer
Alkaline phosphatase(isoenzymes) Obstructive liver diseases and
Bone disorders
Ceruloplasmin Hepatolenticular degeneration
(Wilson’s Disease)
Aldolase Muscle disorders
5’ Nucleotidase Hepato – biliary Diseases
Prostate specific antigen (PSA) Prostate cancer

Front 82

Therapeutic application of the enzymes, Asparaginase/ hyaluronidase/ fibrinolysin/ DNase/streptokinase?

Back 82

Streptokinase: used to lyze(cleave) intravascular clot eg. In MI cases
Asparaginase: Used as anticancer drug in the treatment of tumors. The cancer cells have high requirement of amino acid asparagine. The enzyme asparaginase degrades asparagine, thereby growth of tumor cells is hampered.
Proteolytic enzymes and DNase may be used in wound cleaning

Front 83

Importance of enzymes Taq DNA polymerase, restriction endonucleases, Cholesterol oxidase/glucose oxidase in laboratory?

Back 83

Glucose oxidase: In determination of plasma glucose levels
Cholesterol Oxidase: In determination of plasma cholesterol
Peroxidase: Used as a labeling enzyme In ELISA
Restriction endonuclease: In molecular genetics technology- Recombinant DNA technology, DNA fingerprinting
Taq DNA polymerase: In PCR technology