Module 15: Enzymes

Enzymes

are biological catalysts produced by the activity of living organisms as such as plants, animals & microorganisms and which modify the speed of a reaction without being used up or appearing as one of the end products

Wilhelm Kühne

The name enzyme was suggested in 1867 by

Wilhelm Kühne

Father of enzymology

en zyme

Enzymes is derived from the Greek phrase

"to enliven"

en zyme means

Enzymology

The branch of science that focuses on the study of enzymes

Proteins

all enzymes isolated and studied were proven to be

Enzymes

In general, they are soluble in water, glycerol and dilute alcohol

Amphoteric

Enzymes are characterized by this term which means they can react both as an acid and as a base, thus do not effect the acid-base balance of our body

Reversible

The reactions catalyzed by enzymes are frequently

Cofactor

It is a non protein chemical compound or metallic ion that is required for an enzymes activity as a catalyst considered as "helper molecules" that assist in biochemical transformations

pro-enzyme or zymogen

Some enzymes are synthesized from its inactive precursor called

Zymogen

it is the other term for pro-enzyme a biologically inactive substance which is metabolized into enzymes

Enzymes

They are biological catalysts produced by the activity of living organisms such as plants, animals & microorganisms and which modify the speed oof reaction without being used up or appearing as one of the end prodcucts

Digestion

digest and makes food small enough to be absorbed into the blood through the intestinal walls and be distributed efficiently throughout the body

Detoxification

It is a use of enzymes that refers to the process of eliminating unwanted or poisonous substances from the body

Nourishment

nourish the body with vitamins and minerals. Without enzymes, vitamins and minerals will be useless or merely be excreted out from the body.

Immunity

make up every aspect of the immune system.

White blood cells

are merely trucks transporting enzymes that actually do all the work of healing the body and preventing diseases.

Substrate

It is the term used to denote the substance acted upon by an enzyme

"ase"

The suffix is added to the name of the substance acted upon

Amylase

act on starch (amylum)

Maltase

act on maltose

Cellulase

act on cellulose

Urease

acts on urea

Oxidase

for oxidation

Decarboxylase

It is the name of an enzyme that catalyzes the chemical reaction that removes a carboxyl groupand releases CO2 (decarboxylazation)

Transaminase

It is the name of an enzyme that catalyzes transfer of amino group between an amino acid and an alpha keto acid

Transamination

refers to the removal of the amino group that begins with the transfer of this amino group to an amino group acceptor, usually alpha ketoglutarate that eventually turns into glutamate

Hydrolase

This enzyme catalyzes chemical reactions involving the breaking of complex molecules into simpler ones with the addition of water

Hydrase

An enzyme that catalyzes the addition of water

dehydrase

An enzyme that catalyzes the removal of water

Immunity

It is the use of enzymes coming from WBC that actually do all the work of healing the body and preventing diseases

Lactate dehydrogenase

An enzyme that catalyzes removal of hydrogen atoms from lactate ions

Pyruvate decarboxylase

An enzyme that catalyzes removal carboxyl groups from pyruvate

International Union of Biochemistry Enzyme Commission

What is IUBEC

International Union of Pure and Applied Chemistry

What is IUPAC

2.6.1.2

E.C. number for Alanine aminotransferase

E.C. 3.2.1.1

E.C. number for Amylase

4.2.1.1

Carbonic anhydrase

trypsin

It is the trivial name of an enzyme that helps digest proteins found in pancreatic juice

rennin

An enzyme that coagulates or curds milk used in making cheese and junkets especially

International Union of Biochemistry Enzyme Commission (IUBEC)

instituted a systematic classification scheme of enzymes according to the type of chemical reactions they catalyze

OXIDOREDUCTASES

enzymes that bring about oxidation and reduction

TRANSFERASES

enzymes that catalyze the transfer functional groups from one molecule to another

HYDROLASES

enzymes that bring about hydrolysis, a chemical reaction that involves the breaking of complex molecules into simpler ones with the addition of water

DESMOLASES or LYASES

enzymes that catalyze the addition of a group to a double bond or the removal of a group to a double bond or the removal of a group

LIGASES

enzymes that catalyze condensation or joining of two substrate molecules

ISOMERASES

enzymes that rearrange the functional groups within a molecule and catalyze the conversion of one isomer to another

Mutases

These are isomerases that catalyze the movement of a functional group from one position to another within the same molecule

Mutases

In other words, those enzymes that catalyze intramolecular group transfers

PLASMA SPECIFIC ENZYMES

They are enzymes secreted by the liver into the plasma

NON PLASMA SPECIFIC ENZYMES

They are enzymes that do not specific functions in the plasma since they do not have activators or coenzymes in the plasma

Enzymes of Secretion

they are normally secreted in the plasma at a very high rate but are rapidly disposed off to normal excretory channels thus concentration in plasma is maintained at a low and constant level

Enzymes associated with Cellular Metabolism

they are enzymes that carry out their functions within cells in which they are formed

UNILOCULAR ENZYMES

enzymes that are found only in one location, particularly the cell sap

BILOCULAR ENZYMES

enzymes that are found in the mitochondria and the cell sap

Enzyme variants

refer to the several distinct forms of enzymes that are important in the diagnosis of enzyme specificity as implied by their characteristics

Isoenzymes

are multi-chained enzymes of similar activity typically appearing in specific tissues, organs and cell organelles of organisms with the same species

Isoenzymes

They are specifically located in tissues. The site of a specific isoenzyme is found and restricted to only one tissue.

Isoenzymes

They are charged molecules that can move in an ion exchange resin

Isoenzymes

They respond to activation and inhibition processes

Isoenzymes

They have relative substrate specificities

Alloenzymes

They are genetically transmitted enzymes

Alloenzymes

Important in defining the biochemical characteristics of an individual

Alloenzymes

They are present only in some selected individuals of the same species

Alloenzymes

Practical value in forensic medicine and genetics

HETEROENZYMES

are those with the same enzymatic activity which are specific for different biological species

Catalase

It is a common oxidoreductase found in nearly all living organisms exposed to oxygen which catalyzes the decomposition of hydrogen peroxide to water and oxygen

Proteolytic enzymes

They refer to enzymes that work best in acidic conditions like pepsin and gastrin

Enzyme substrate combination

other name for SIMPLE ENZYME ACTION

Michaelis and Menten

The theory in simple enzyme action (enzyme-substrate combination) was proposed by?

Enzyme coenzyme systems

other name for Complex enzyme action

Complex enzyme action

is more complex than the first

Apoenzyme

It is the caralytically inactive protein part to which coenzyme attaches itself

Lipase

It is the enzyme that catalyzes the hydrolysis or digestion of fats

Coenzyme

This are enzymes whose metal ions are intrinsically part of the molecule

Allosteric sites

It is a site that allows molecules to either activate or inhibit enzyme activity

Holoenzyme

It is the catalytically active combination of the apoenzyme and coenzyme

HIGH DEGREE OF SPECIFICITY:

This is one of the most noteworthy properties of enzymes.

HIGH DEGREE OF SPECIFICITY:

This means that a given enzyme will act only on a particular substance or close-related substances.

HIGH DEGREE OF SPECIFICITY

This is explained by the fact that enzymes act and attack a compound at specific reactive site and definite type of linkage.

ABSOLUTE specificity

it is a type of enzyme specificity that occurs when the enzyme acts on a one and only substrate

GROUP or RELATIVE specificity

it is a type of enzyme specificity that occurs when an enzyme can act on several substrates with related structure but at  different intensities

LINKAGE specificity

it is a type of enzyme specificity that occurs when an enzyme catalyzes the formation or breakage of only certain bonds in a molecule

STEREOCHEMICAL specificity

it is a type of enzyme specificity that occurs when an enzyme can act on only a substance with specific configuration

LOCK AND KEY MODEL

this model was devised by Emil Fischer in 1894 that refers to the rigid active site of  an enzyme being complementary to the shape and size of only one kind of substrate

Emil Fischer

LOCK AND KEY MODEL was devised by

INDUCED FIT MODEL

it is proposed by Daniel Koshland Jr. in 1956 stating that some enzymes can probably change their size and shape when binding with their substrates

INDUCED FIT MODEL

This model is more acceptable because the protein molecule is flexible enough to allow conformational changes and also allows some explanation on the influence of hormones on enzymatic activity

Daniel Koshland Jr

INDUCED FIT MODEL is proposed by

point of equilibrium

As the products of the reaction increase in amount, the reaction approaches the

37 to 40 0C

Enzymes of animal origin have an optimum temperature of inactivation and destruction

ENERGY

this refers to the amount of energy needed to activate an enzyme to catalyze a certain chemical reaction

MOLECULAR COMPATIBILITY

commonness or sameness between an enzyme and a substrate

SPACE AVAILABILITY

refers to the number of enzymes or substrates that can be reacted

SPECIFICITY

refers to the particular enzyme catalyzing a specific substrate

SUBSTRATE CONCENTRATION

Other conditions being kept constant, an increase in the concentration of the substrate will increase the rate of activity

ENZYME CONCENTRATION

Using a highly purified enzyme, the velocity of the reaction is directly proportional to the concentration of the enzymes

pH LEVEL(Hydrogen Ion Concentration)

Each enzyme requires a definite pH zone. This has been discussed under characteristics of enzyme action.