3

• Life depends on series of chemical reactions

• Chemical reactions are far slow to maintain life

• Living system has designed catalysts to fasten the specific reactions

• Enzymes accelerate the rate of chemical reactions in living organisms.

• Like all catalysts, enzymes work by lowering the amount of activation energy needed for a reaction to occur and thus dramatically accelerating the rate of the reaction.

Enzymes are Enzymes are proteinsproteinsproduced by different cells of humans, animals, plants and microorganisms

را بیوشیمیایی های واکنش سرعت ها آنزیمتعادلی وضعیت بر تاثیری اما دهند می افزایش

. ندارند واکنش

Enzymes– Definition

A reusable protein molecule that brings about chemical change while remaining unchanged itself.

Enzymes– Break and form covalent bonds– Move large structures– Effect three dimensional structure– Regulate gene expression

Enzymes

• lower an energy of activation (EA)

• reduce the time to reach the reaction equilibrium

• don´t change the equilibrium position of the reaction

• are not consumed or changed by the reaction• are specific• can be regulated

self study

Cells & Enzymes

Enzymes

Made of protein Present inall living cells

Converts substratesinto products

Biological catalysts

Increase the rate of chemical reactions

Remain unchanged by chemical reaction

ها کاتالیزور با مقایسه در ها آنزیم: کنند می عمل اختصاصی بسیار

به ها آنزیم بودن صورت 2اختصاصیاست :

Absolute Specific ) مطلق ) اختصاصیروی: • بر فقط که گلوگوکیناز مثال

دارد گلوکزاثر

Broad Specificity ( اختصاصیگسترده(

پیوند : • روی بر که ترپسین آنزیم مثالآمینه های اسید که پپتیدی , Argهای

Lys کند می عمل دارد وجود

S PEE

های واکنش در کلی بطورآنزیم توسط که بیوشیمیایی

شود می شرکت 3کاتالیز جسمدارد

• – ) سوبسترا ) اولیه مادهقرار آنزیم تاثیر تحت که جسمی

گیرد می

اثر – • سوبسترا روی آنزیممی کاتالیز را واکنش و نموده

کند

واکنش – • جریان در محصولشود می تولید

S

EE

P

A + B C + D

آنزیم حضور در واکنش واکنش 10 11 – 103سرعت سرعت برابربود خواهد آنزیم حضور بدون

A + B

C + D

Enzyme kinetics

• activity, units

1 IU = 1 μmole of a substrate transformed per 1 minute

1 katal = 1 mole of a substrate transformed per 1 sec

1 katal = 6 x 107 IU

S PEE

A-X

A-X

+

A

BE

A + B-X

E

E-X

B

B-X

شوند نمی مصرف اما کنند می دخالت واکنش در آنزیم های ملکولرا سوبسترا ملکول ها میلیون تواند می آنزیم ملکول یک این بنابر

نماید تبدیل محصول به

One Enzyme – One Reaction

There are thousands of different enzymes in your body.

Active Site( فعال مکان (آنزیم

می • پیوند آنزیم از مخصوصی مکان به تنها آنزیم هر سوبسترایکه آنزیم گردد فعال آنزیم مکان فعال شود مکان می نامیده

حالت • فعال است 3مکان اختصاصی انزیم هر برای که دارد بعدیاثر • در که است امینه های اسید ای مجموعه آنزیم هر فعال مکان

می شکل پپتیدی پلی زنجیره گرفتن قرار هم روی و خوردگی تاگیرد

است • رفته فرو آنزیم درون آنزیم فعال مکان

EE

Active Active SiteSite

SS

Enzyme is a biocatalyst:

1890 -Fischer

بنام : آنزیم از خاصی جایگاه به آنزیم یک سوبسترای فرضیهفعال شود Active Siteجایگاه می متصل

باشد می سوبسترا مکمل جایگاه شکلساختمان – جزئی معین – 3محدوده شکل بعدی

lock-and-key’ hypothesislock-and-key’ hypothesis

E E

• The lock and key hypothesis states that the active site specifically matches the shape of the substrate molecule

enzyme

Each enzyme is specific to one substrate molecule or type of molecule

active site

SS

Lock & Key Hypothesis

An enzyme only acts on one type of substrate.

Therefore, the enzyme is said to be SPECIFIC to its one substrate.

The shape of the active site (binding site) of the enzyme, matches the shape of the substrate. Allowing the two molecules to bind during the chemical reaction.

This theory of enzyme action is called the ‘lock-and-key’ hypothesis.

شکل آنزیم فعال جایگاههنگام در و ندارد معینی

به سوبسترا با ترکیبشکل یا و مطلوب شکلمی در سوبسترا مکملتناسب را پدیده این آید

نامند می القایی

Induction FitInduction Fit

EE

S

S

The figure is found at: http://fig.cox.miami.edu/~cmallery/255/255enz/enzymology.htm (December 2006)

می ضعیف و سست اتصاالت نوع از سوبسترا و آنزیم بین پیوندباشد کوواالنسی اتصاالت نوع از تواند می گاها ولی باشد

.) ترپسین)

E + S ES E + P

الکترواستاتیکی•هیدروژنی••) هیدروفوب ) واندروالسی

Structure of enzyme

• A precise 3-dimensional shape: linear array of a.a. (primary structureprimary structure) folds and twists into a specific configuration (second & tertiary structuresecond & tertiary structure)

• May be a simplesimple enzyme (protein only)(protein only) or conjugatedconjugated enzyme

• Conjugated enzymes need other non-protein molecules for activation

• (protein + non-protein)

ApoenzymeApoenzyme CofactorCofactor HoloenzymeHoloenzyme

Cofactors

• non-protein: • Metal ions and organic cofactors (usually derived

from B vitamins) are major groups of cofactors.

ساختمان ( (Prosthetic groupsفلزات در قوی های پیوند با معموالکنند : می شرکت ها آنزیم Metalloenzymeپروتئینی

ها ویتامین نظیر آلی ترکیبات بصورت که هایی کوفاکتور CoenzymeCoenzymeهستند :

Holoenzyme

=

Apoenzyme– Large molecular wt.– All protein– Contains active site +

Coenzyme–Organic

orProstatic

–Metallic

Cofactor

31

Enzymes

Naming

Classification

When enzymes were first discovered scientists named them. Although they added the “in” suffix to most there was no uniformly accepted method of naming enzymes

Trypsin Trypsin PepsinPepsinChymotrypsinChymotrypsin

تجربی تجربی نامگذاری نامگذاری

Today enzyme’s name is derived from its substrate or the chemical reaction it catalyzes, with the word ending in “-ase”

(( براساسنوع واکنش یا سوبسترانامگذاری نوع

آز+ a) Substrate name + -ase (Amylase)

b) Reaction type + -ase (Dehydrogenase)

Cellulase, protease, amylase, lipase, glucose Cellulase, protease, amylase, lipase, glucose oxidase, DNA polymeraseoxidase, DNA polymerase

Decarboxylase, Hydrolase, Dehydrogenase, Abbreviations of enzymes * used in medicine

LDH, ALT, ALP,…Abbreviations of enzymes * used in medicine

LDH, ALT, ALP,…

35

Now, each protein is given an Enzyme Classification Number (EC). The method of classification is by the type of type of reaction the enzyme catalyzesreaction the enzyme catalyzes

ECEC

EC 1 – Oxidoreductases EC 1 – Oxidoreductases EC 2 – Transferases EC 2 – Transferases EC 3 – Hydrolases EC 3 – Hydrolases EC 4 – Lyases EC 4 – Lyases EC 5 – Isomerases EC 5 – Isomerases EC 6 – Ligases EC 6 – Ligases

1) OOxidoreductasesxidoreductases: Aox + Bred Ared + Box

* dehydrogenase (H- or H)

* reductase

* oxidase

* peroxidase (various peroxides)

* oxygenase (O2)

* hydroxylase (= monoxygenase; -OH)

کنند می کاتالیز را احیا و اکسیداسیون 0واکنشهایمی دیگر ملکول احیائ و ملکول یک اکسیداسیون باعث

باشند. می کوانزیم یک دارای اغلب ها آنزیم این شوند

Oxidoreductases

Alcohol Dehydrogenase: ADH

CH3CH2OH + NAD+ CH3CH2O + H+

+NADH

Catalyses conversion of ethanol to aldehyde using co-enzyme NAD+NAD+ oxidized to NADH reduced

2) TTransferases:ransferases:A-x + B A + B-x

* grouptransferase (e.g. aminotransferase)

* kinase (= phosphotransferase)

* phosphorylase

* Transketolase

* Transaldolase

بجز ) کنند می کاتالیز دیگر ملکول به ملکولی از را گروهایی انتقالهیدروژن(

CH3

G + ATP → G6p + ADP گلوکوکیناز:

TTransferasesransferases

3) HHydrolases:ydrolases: A-B + H2O A-H + B-OH

* esterase (R1-CO-O-R2)

* phosphatase (phosphate-O-R) Pi !!!

* phosphodiesterase

(R1-O-phosphate-O-R2)

* nuclease, peptidase, glycosidase,

lipase دهند می انجام را مختلف های پیوند هیدرولیز عمل

Hydrolases

4) lyases: A-x B + x

* decarboxylase ( CO2)

* dehydratase ( H2O)

* synthase

پیوند تشکیل با تواند می که کنند می کاتالیز را گروههایی برداشت ) برعکس ) یا باشد همراه دوگانه

catalyze the cleavage of C-C, C-O, C-S and C-N bonds by means other than hydrolysis or oxidation.  leaving double bonds or rings, or conversely adding groups to double bonds

catalyze the cleavage of C-C, C-O, C-S and C-N bonds by means other than hydrolysis or oxidation.  leaving double bonds or rings, or conversely adding groups to double bonds

Lyases

5) isomerases: A iso-A

* epimerase (monosacharide its epimer)

* mutase (rearangement of a phosphate group)

– : ترانس سیس کنند می کاتالیز را شدن ایزومری عمل

Isomerases

ملکول درون در را گروهها انتقال های واکنشنمایند می کاتالیز

مراز – اپی ... ایزومراز

فسفات استن هیدروکسی دی به فسفات گلیسرآلدئید تبدیلایزومراز آنزیم توسط

6) ligases: A + B + ATP A-B + ADP + Pi

* synthetase

* carboxylase

ترکیب و پیوند باعث ها آنزیم که . 2این حالی در شوند می ملکولشدن شکسته با پیوند ایجاد گردد ATPانرژی می تامین

Ligases

CH3-CO-S-COA + CO2 CH3-CO-S-COA + CO2 →→ COOH-CH2-CO-S-COACOOH-CH2-CO-S-COA

ATPATP ADP + PiADP + Pi

توسط آ کوانزیم استیل از آ کوانزیم مالونیل تشکیللیگاز آنزیم

Scheme of Enzyme Classification by IecThe IEC gives a code and each letter contains it’s own significance in relation to that particular enzyme. During classification every enzyme is prefixed by EC, followed by the digits.

For example: oxidoreductases EC 1.1.1.1(a)The first digit denotes “Class” of the enzyme(b)The second digit indicates “Sub-class” of the

enzyme(c)The third digit gives “Sub sub-class” of the enzyme

(d)The fourth digit in the code is “Serial number” of the enzyme

Kinetics

• Temperature Effect• PH Effect• Enzyme Concentration Effect• Substrate Concentration Effect

• At low temperatures enzyme controlled reactions go slowly because the molecules have low kinetic energy.

The rate of an enzyme controlled reaction is

affected by temperature

واکنشهای بر حرارت واکنشهای اثر بر حرارت اثرآنزیمی آنزیمی

But this only occurs up to the optimum temperature (usually about 40oC)

The temperature at which the rate of reaction is fastest is known as the optimum temperature

When temperature increases the reaction also increases as the molecules have more kinetic energy

After the optimum temperature the heat causes the enzyme to denature

• The enzyme changes shape and the active site no longer matches the shape of the substrate molecule

دارای مخالف 2افزایشحرارت اثرآنزیمی واکنشهای سرعت در

است

سرعت افزایشواکنش

کردن فعال غیرآنزیم

RateOf Reaction

Temperature/oC0 10 20 30 40 50 60 70

Optimum temperature

Enzyme is denaturing

Rate of reaction of an enzyme reaction changes at different temperatures

Molecules gain kinetic energy

2.5 Effect of High Temperature

Notes on DenaturationNotes on Optimum

temp

What happens to the activity of an enzyme at high temperatures?

• Enzymes prefer to work at an optimum pH. Outside of its pH range the enzyme is denatured.

RateOf Reaction

pH

1 2 3 4 5 6 7 8 9 10 11 12

pepsin amylase

The activity and shape of enzymes is also affected by pH

Optimum pH

Effect of pH on enzymes

When the pH changes outwith optimal conditions, the shape of the active site of the enzyme alters and the enzyme is denatured.

MovieMovie

Effect of pH on enzymes

When the pH changes outwith optimal conditions, the shape of the active site of the enzyme alters and the enzyme is denatured.

PHتغییرات

می آنزیم پروتئین شدن فعال غیر و تغییر سببگردد

فضایی شکل و سوبسترا یونیزاسیون در تغییر سببگردد می آن

در موجود آمینه های اسید یونیزاسیون در تغییر سببسوبسترا و آنزیم ترکیبی میل بر و شده فعال جایگاه

است موثر

Effect of pH on enzyme activity

Most enzymes work best at a pH close to neutral (pH 5-7), but there are some exceptions. Pepsin, an enzyme found in the stomach, has an optimum pH of 2.

PH ایدر که

آن آنزیم

حداکثر فعالیت

از راخود

نشان می دهد

PHPH اپتیماپتیم

وم:وم:

Substrate Saturation of an Enzyme

A. Low [S] B. 50% [S] or Km C. High, saturating [S]

The activity is related to a constant concentration of an enzyme:

[E] = constant

Effect of substrate

Michaelis-Menten Equation

V0 = Vmax [S]

Km +[S]

Enzyme Kinetics Equation

Michaelis-Menten Equation

V0 = Vmax

[S]

Km +[S] K2

Km نشان را سوبسترا به آنزیم تمایلدهد میKm : بیشتر تمایل : Sبه Eکوچک

تولید بیشتر PسرعتKm: کمتر بزرگ : Sبه Eتمایل

تولید کمتر Pسرعت

Michaelis-Menten kinetics• the curve can be described by the equation:

S<< Km →→ V0 =

Vmax

[S]

Km

V = K [S] درجه 1معادله

درجه نوع از واکنش است کم سوبسترا غلظت V~ Sاست : 1وقتی

Michaelis-Menten kinetics• the curve can be described by the equation:

Km<< s →→ V0 = Vmax

است صفر درجه نوع از واکنش است زیاد سوبسترا غلظت وقتی

صفر درجه معادله

Michaelis-Menten kinetics• the curve can be described by the equation:

S= Km →→ V0 =

Vmax

2Km واکنش سرعت غلظت آن در که است سوبسترا از غلظتی

باشد ماکزیمم سرعت نصف آنزیمی

The figure is found at: http://fig.cox.miami.edu/~cmallery/255/255enz/gk3x15.gif (December 2006)

Km describes an affinity of the enzyme to its

substrate! indirect proportionality!

linearization of the curve:

y = k x + q

Lineweaver-Burk (double reciprocal plot)

Lineweaver-Burk (double reciprocal plot) (cont)

Lineweaver-Burk Plot

1 Km 1V0 Vmax [S] Vmax

Measure Vo with increasing [S]

Different enzymes for different jobs

Enzymes involved in breakdown reactions

Enzyme and substrate separate

Enzyme-substrate complex

Enzyme and products separate

Enzymes involved in synthesis reactions

Enzyme and substrates separate

Enzyme-substrates complex

Enzyme and product separate

Rates of enzyme reactions can be measured by recording the time for a substrate to disappear or a product appears

protein polypeptidestrypsin

white clear

Controlled variables:

•Volume and concentration of substrate (milk)•Volume and concentration of enzyme (trypsin)•pH (controlled by buffers)•Temperature

Enzymes involved in breakdown reactions

CatalaseHydrogen peroxide Water + Oxygen

AmylaseStarch Maltose

LipaseFat Fatty acids + Glycerol

PepsinProtein Amino acids

2.4 Synthesis reactions

phosphorylase

glucose-1-phosphate starch

What is phosphorylase?

Phosphorylase is an enzyme that synthesises starch.

What is substrate of phosphorylase?

Glucose-1-phosphate

What is the product?

Starch

B. Structure of Enzymes

Isoenzymes (isozymes) are enzymes which catalyze the same reaction but differ in their primary structure and phyzico chemical properties

Isoenzymes are

• produced by different genes (= true isozymes)

• or produced by different posttranslational modification (= isoforms)

• found in different compartments of a cell

• found in different tissues of an organism

• can be oligomers of various subunits (monomers)

C. How Enzymes Work

97

Properties of enzymes

1) Specificity 專一性 Most enzymes are absolute or near-absolute specific to the substrates

- Some enzymes that react with wide range of substrates are peptidises, phosphatases, esterases (bond specific), and hexokinases (group specific)

2) Regulation 調節性 Enzyme activities can be regulated by small ions or small molecules (effectors), such as phosphate or Ca2+

The regulations are mediated by changing covalent structure

98

S + E ES E + P

S: substrate﹝ ﹞ E: enzyme ﹝ ﹞ ES: enzyme-substrate complex ﹝ ﹞

transition state P: product ﹝ ﹞

• Highly specific to the substrate of reaction that it catalyzes due to 3-D structure of the folded protein each enzyme catalyzed only a single type of chemical reaction

k1

k2

k3

99

100

affect only the speed, but not energetic or equilibrium of a reaction Unidirectional enzyme itself does not change structure after participating rxn; can be used repeatedly

101

Nomenclature of enzymes

• Some enzyme names are unhelpful to figure the reaction catalyzed, eg. catalase, trypsin, papain….

• IUBMB (International Union of Biochemistry and Molecular Biology ) was set up in 1955

• Six classes of enzymes：1. Oxidoreductase2. Transferase3. Hydrolase4. Lyase5. Isomerase6. Ligase

102

The Enzyme Commission number (EC number)• a numerical classification scheme for enzymes, based on

the chemical reactions they catalyze.• EC number system: 4-digit system, ex.: EC 1.2.2.1

1st number : Class of the enzyme2nd number : subclass by the type of substrate or the bond cleaved3rd number : subclass by the electron acceptor or the type of group removed4th number : serial number of enzyme found

• Classification based on the chemical reaction catalyzed, noton the source (species or tissues) of the enzyme – Aminoacid sequence may be very different

103

Enzyme classification

(A) Location of action• Endoenzyme: intracellular; most enzymes of the

metabolic pathways.

• Exoenzyme: extracellular; break down (hydrolyze) large food molecules or harmful chemicals. Example: cellulase, amylase, penicillinase.

104

Enzyme classification cont.(B) Presence in cell• Constitutive Enzyme: enzymes synthesized by the cell

in the absence of any specific stimulus; always present in cell regardless of the amount of substrate; enzymes that are always present and active .

• Inducible Enzyme: enzymes whose synthesis is stimulated in the presence of a chemical (substrate) or physical stimulus (heat, light); not constantly present in cell and is produced only when the stimulus is present; enzymes that are synthesized or activated when needed . prevent a cell from wasting energy by making enzymes that will not be used immediately

105

Exoenzyme Endoenzyme

Constitutive enzyme

Inducible enzyme

106

Enzyme classification cont.(C) Biochemical action: 6 classes; dependon the nature

of the reaction catalysed 1. Oxidoreductase : redox reaction; transfer e- or H+

from one compound to another. 2. Transferase : transfer functional groups from one

substrate to another. 3. Hydrolase : cleave bonds of molecules with

addition of water. 4. Lyase: add or remove functional groups from

double-bonded substrates. 5. Isomerase : change substrate into its isomeric form. 6. Ligase: formation of bonds so substrates can bind

together; also known as synthetases; need input of ATP and removal of H2O.

Factors – Substrate Concentration

Effect of [Substrate]

Enzyme Inhibition

1.Types of Inhibition– Competitive

– Folic Acid inhibition by Sulfanilamide competition with PABA

– Noncompetitive– Fluoride binding with Ca or Mg atoms

in enzymes

Inhibition of enzymes

Sometimes, a molecule that roughly resembles the normal substrate can fit into the active site, and thereby prevent the enzyme from acting on the substrate. This form of inhibition is called competitive inhibition

1) Competitive inhibition

• inhibitor resembles substrate

• it is bound to an active site but not converted by the enzyme

• increases Km (afinity of enzyme to its S)

• if concentration of a substrate is increased the inhibition is decreased

• the inhibition is reversible

Competitive Inhibition

Reversible Competitive Inhibition

.

 

In non-competitive inhibition, the inhibitor molecule binds to a site other than the active site of the enzyme, and thereby changes the 3-dimensional structure sufficiently to prevent the normal subsrate from fitting into the active site. This is sometimes called allosteric inhibition.

Noncompetitive Inhibitor

• inhibitor binds at a site other than the substrate-binding site

• inhibition is not reversed by increasing concentration of substrate(no Km change)

• Vmax is decreased (it is related to decreasing of active enzyme concentration)

• reversible only if the inhibitor is not bound by covalent bond

2) Noncompetitive inhibition

Non-Competitive Inhibition

Uncompetitive Inhibitor

Irreversible Inhibitor: Allopurinol

The figure is found at: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/EnzymeKinetics.html (December 2006)

Summary of the inhibition

Some enzymes can be inhibited also byan excess of their substrate

The figure is found at: http://www-biol.paisley.ac.uk/Kinetics/chapter_3/chapter3_6_1.html (December 2006)

The figure is adopted from the book: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

Allosteric enzyme: a) monomeric, b) oligomeric

The figure is adopted from the book: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

Allosteric enzyme in T and R conformations: modulators shift the equilibrium

inhibitors have a greater

affinity forT-state

activators and

substrates have a greater

affinity for R-state

Inhibition by drugs and poisons

a) reversible

b) irreversible

inhibitor is bound covalently into the active

site of enzyme

Inhibition as a regulation of metabolic pathways:

inhibition by products or intermediates:

a) feedback regulation

b) cross-regulation

c) feedforword regulation

inhibition by

d) reversible covalent modification

(e.g. phosphorylation / dephosphorylation)

Allosteric

regulation

• activator is „a positive modulator“

• inhibitor is „a negative modulator“

The figure is found at: http://www-biol.paisley.ac.uk/Kinetics/Chapter_5/chapter5_2_2.html (December 2006)

! the curve of allosteric enzymes is sigmoidal not hyperbolic !

Inhibition of enzymes used in the regulation is either

• competitive

(Km is increased above substrate concentration within a cell)

or • allosteric

(by conformational changes affecting the catalytic site)

Determination of enzyme activity for diagnostic purposes

most often blood is investigated (serum, plasma)

evaluation of presence and seriousness of a tissue damage

units: kat/L (= catalytical concentration of enzyme)

kat = katal

1 katal = 1 mole of a substrate transformed per 1 sec

1 kat = 10-6 kat

3. Enzyme Classification– Based on where the enzyme activity

occurs.– Exoenzymes

– Endoenzymes

Endogenous enzymesDigestion:

For example during digestion, intestinal cells produce alimentary enzymes, which split the food into such small molecules so they can be absorbed into the blood. These

enzymes include Trypsin, Chymotrypsin, Amylase, Lipases, Pepsin, Sucrase, Maltase, etc.

Inflammation:During an inflammation, proteolytic enzymes are produced by

neighbouring cells, so that the blood clotting process can happen and to remove destroyed tissue. Different enzymes are

involved in the process: the enzyme Thrombin, which is important for blood clotting or Elastase, a proteolytic enzyme,

involved in tissue degradation

Exogenous EnzymesIngested enzymes (from plants, animals, bacteria and fungi) are absorbed in a small amount of our gut and attain the blood, where they have some

effects.It is therefore not amazing that treatment with enzymes is used since thousands of years in

different cultures – even nobody knows how it works.

4جواب

است : نوع چه از سوبسترا با آنزیم پیوند

هیدروفوب 1. پیوند

هیدروژنی 2. پیوند

الکترواستاتیک 3. پیوند

مورد 4. سه هر

1جواب

است : درست عبارت کدام

دارد 1. بعدی سه ساختمان آنزیم فعال مکان

دهد 2. می تشکیل آنرا ساختمان اعظم قسمت انزیم فعال مکان

شوند 3. می متصل محکم پیوند با فعال مکان به ها کوانزیم تمام

شوند 4. می متصل ضعیف پیوند با فعال مکان به ها کوانزیم تمام

1جواب

است : نوع چه از کند می کاتالیز را زیر واکنش که آنزیمی

ترانسفراز1.

لیاز2.

هیدروالز3.

ایزومراز4.

کراتین کراتین فسفو

ATPATP ADPADP

1جواب

است : درست عبارت کدام

دارد 1. بعدی سه ساختمان آنزیم فعال مکان

دهد 2. می تشکیل آنرا ساختمان اعظم قسمت انزیم فعال مکان

شوند 3. می متصل محکم پیوند با فعال مکان به ها کوانزیم تمام

شوند 4. می متصل ضعیف پیوند با فعال مکان به ها کوانزیم تمام

CH3-CO-S-C