Access free live classes and tests on the app
Download
+
Unacademy
  • Goals
    • AFCAT
    • AP EAMCET
    • Bank Exam
    • BPSC
    • CA Foundation
    • CAPF
    • CAT
    • CBSE Class 11
    • CBSE Class 12
    • CDS
    • CLAT
    • CSIR UGC
    • GATE
    • IIT JAM
    • JEE
    • Karnataka CET
    • Karnataka PSC
    • Kerala PSC
    • MHT CET
    • MPPSC
    • NDA
    • NEET PG
    • NEET UG
    • NTA UGC
    • Railway Exam
    • SSC
    • TS EAMCET
    • UPSC
    • WBPSC
Login Join for Free
avtar
  • ProfileProfile
  • Settings Settings
  • Refer your friendsRefer your friends
  • Sign outSign out
  • Terms & conditions
  • •
  • Privacy policy
  • About
  • •
  • Careers
  • •
  • Blog

© 2023 Sorting Hat Technologies Pvt Ltd

Watch Free Classes
  • NEET 2024
  • NEET Rank Predictor 2023
  • NEET College Predictor 2023
  • Study Materials
  • Notifications
  • NEET Syllabus 2023
  • NEET Question Paper
  • NEET Notes
  • NEET Books
  • NEET Paper Pattern
  • Video Lectures
  • Mind Maps
  • Downloads
  • Difference Between
  • Full Forms
  • Exam Tips
  • MCQs
NEET UG » NEET UG Study Materials » Biology » Active Site
neetug_toolkit

Active Site

The active site of an enzyme is the part of the enzyme where substrate molecules bind and a chemical reaction takes place. The active site is made up of amino acid residues that establish temporary bonds with the substrate (binding site) as well as residues that catalyse that substrate's reaction (catalytic site).

Table of Content
  •  

The portion of an enzyme that binds substrate molecules is known as the active site. This is critical for the catalytic activity of the enzyme.

Enzymes are proteins that reduce the activation energy of chemical reactions, allowing them to move much faster. They accomplish this by interacting with chemical reactants – the substrates – in ways that encourage them to undergo chemical reactions. This interaction takes place in the enzyme’s active site, where the substrates are bound to maximise their chances of reacting.

Active Site Specificity: 

Ionic Charge : Positive and negative charges are attracted to each other. Similar charges, such as two positive charges, repel each other actively. Another way an enzyme active site might attract substrates or parts of substrates while rejecting others to obtain the perfect fit is through a mechanism known as repulsion.

Polarity : Non-polar molecules prefer other non-polar molecules, whereas polar molecules prefer other polar ones. Certain amino acids in the active site might therefore attract or repel different sections of the substrate, resulting in a better match.

Hydrophobicity or hydrophilicity : Opposites do not attract in this scenario. Instead, what attracts what draws. Hydrophilic amino acids attract hydrophilic substrates, while hydrophobic amino acids attract other hydrophobic compounds.

Size and shape of the active site : The active sites of enzymes are structured in such a way that they can only ‘fit’ with specific substrates.

Some vitamins and minerals are necessary because they act as cofactors, assisting enzymes in binding to their substrates. Enzymes involved in energy production, for example, utilise various B vitamins as cofactors. That’s why B vitamins are found in many energy “shots” and supplements.

The Active Site’s Features

  • The active site is a three-dimensional cleft produced by groups from various amino acid sequences.
  • The active site of an enzyme occupies a modest portion of the total volume of the enzyme.
  • Clefts or crevices are active locations.
  • Multiple weak attractions bind substrates to enzymes.
  • Binding specificity is determined by the precise arrangement of atoms in an active site.

The Process :

An enzyme will bind to one or more reactant molecules in order to catalyse a process. The enzyme’s substrates are those compounds.

One substrate can be broken down into a number of products in some reactions. In other cases, two substrates are combined to form a bigger molecule or portions are swapped. In fact, there is most likely an enzyme to speed up any biological reaction you can think of!

The active site (where the catalytic “activity” takes place) is the region of the enzyme that binds the substrate.

Proteins are formed up of units called amino acids, and the amino acids that make up the active site in enzymes give it its properties. These amino acids can have large or small side chains, acidic or basic, hydrophilic or hydrophobic side chains.

The active site’s amino acid composition, as well as their relative placements in 3D space, give it a distinct size, shape, and chemical behaviour. An enzyme’s active site is specifically designed to bind to a specific target—the enzyme’s substrate or substrates—and assist them in undergoing a chemical reaction thanks to these amino acids.

Binding Theories :

Lock and Key Model :

Emil Fischer, a 19th-century chemist, proposed this concept. He claimed that the active site and substrate are two stable structures that, like a key and a lock, fit together properly without any further change. The interactions between substrates will be strongest if one perfectly binds to its active site, resulting in high catalytic efficiency.

As time passed, the model’s shortcomings became apparent. The competitive enzyme inhibitor methylglucoside, for example, can bind tightly and precisely to the active site of 4-alpha-glucanotransferase. On methylglucoside, however, 4-alpha-glucanotransferase is inactive, and no glycosyl transfer occurs. Because of its strong binding, the Lock and Key hypothesis cannot explain this, as it would predict a high efficiency of methylglucoside glycosyl transfer. Apart from competitive inhibition, this theory is unable to explain the mechanism of non-competitive inhibitors, which do not bind to the active site yet nonetheless influence catalytic activity.

Induced Fit :

The active site and the binding part of the substrate are not exactly complementary, according to Daniel Koshland’s theory of enzyme-substrate binding. The induced fit model is a variation on the lock-and-key model, in which an active site is flexible and changes form until the substrate is completely bound. This model works in the same way that a glove does: the glove changes shape to fit the hand. The enzyme’s shape attracts its substrate at first. The surface of an enzyme is flexible, and only the right catalyst may cause interaction, which leads to catalysis. As the substrate is bound, conformational changes may occur. The reaction products will move away from the enzyme after the reaction, and the active site will revert to its original structure. The fact that the entire protein domain can migrate several nanometers during catalysis supports this notion. This mobility of the protein surface can lead to the formation of microenvironments that are conducive to catalysis.

Conclusion :

The active site is a groove or pocket created by the protein’s folding structure. This region of the enzyme is the only one that binds to the substrate. The enzyme-substrate complex has a three-dimensional structure. Because of this, as well as the chemical features of the amino acids and co-factors, only a single substrate may bind to the site, making it specific to individual proteins.

faq

Frequently asked questions

Get answers to the most common queries related to the NEET UG Examination Preparation.

What is the difference between a substrate and an active site?

Ans: We use the terms substrate and active site to describe catalytic r...Read full

What does an enzyme's active site look like?

Ans: The active site is the part of the enzyme that binds the substrate...Read full

What is the induced fit enzyme activity model?

Ans: The induced fit concept states that when an enzyme binds a substra...Read full

Ans:

We use the terms substrate and active site to describe catalytic reactions that use enzymes as the catalyst. The distinction between a substrate and an active site is that the former is a chemical substance capable of undergoing a chemical reaction, while the latter is a specific location on an enzyme.

 

Ans:

The active site is the part of the enzyme that binds the substrate.

Ans:

The induced fit concept states that when an enzyme binds a substrate, the active site undergoes a conformational change to improve the fit. The induced fit model ignores a transition state during which the active site’s shape changes to better fit the substrate.

Crack NEET UG with Unacademy

Get subscription and access unlimited live and recorded courses from India’s best educators

  • Structured syllabus
  • Daily live classes
  • Ask doubts
  • Tests & practice
Learn more

Notifications

Get all the important information related to the NEET UG Examination including the process of application, important calendar dates, eligibility criteria, exam centers etc.

Best Books for NEET 2023 – Physics, Chemistry & Biology
How to Prepare for NEET 2024 at Home Without Coaching?
Last 10 Years NEET Question Papers – Download NEET Previous Year Question Paper with Solutions PDFs
NEET 2023 Counselling – Schedule, Dates, Fees, Seat Allotment
NEET Answer Key 2021 – Download PDF
NEET Eligibility Criteria 2024
NEET Exam Calendar
NEET Exam Information
NEET Exam Pattern 2023 – Check Marking Scheme, Subject-wise Question Distribution
NEET Marking Scheme
NEET Registration Date Extension
NEET Registration Fees
NEET Registration Process
NEET Result 2023 (OUT): Download Link @neet.nta.nic.in, NEET Score card
NEET Syllabus 2023
NEET Syllabus with Weightage – NEET Chapter-wise Weightage
NEET UG Exam Analysis
NEET UG Hall Ticket 2023 – Check Steps to Download
NEET UG Previous Papers Analysis
See all

Related articles

Learn more topics related to Biology
Zygote

In this chapter we will discuss zygote definition, formation of zygote, development of zygote and much more.At last we will discuss some important questions related to this topic.

Zoology

Zoology is the branch of biology that is concerned with the study of the animal kingdom. It is the scientific study of all of the species of the animal kingdom as a whole, including humans.

Zoological Park

This article gives you an insight into the zoological parks, the advantages and disadvantages of zoos and much more.

Zinc

In this article we were going to learn about the topic of Zinc in detail with examples and uses.

See all
Access more than

9,257+ courses for NEET UG

Get subscription

Trending Topics

  • NEET Preparation Tips
  • How to Prepare for NEET from Class 11?
  • How to Prepare for NEET?
  • NEET 2023
  • NEET Syllabus 2023
  • NEET Question Paper
  • NEET Exam Pattern
  • NEET Toppers 2022
  • NEET Notification
  • NEET 2022 Answer Key
  • NEET Exam Calendar
  • NEET Results
  • NEET Eligibility
  • NEET Preparation Books

NEET Previous Year Question Papers

  • NEET 2022 Question Paper
  • NEET 2021 Question Paper
  • NEET 2020 Question Paper
  • NEET 2019 Question Paper
  • NEET 2018 Question Paper
combat_neetug

Related links

  • NEET Study Materials
  • How Many Attempts for NEET
  • How Many Marks Are Required in NEET for MBBS
  • Living World NEET Questions
  • MBBS Full Form
  • NEET Full Form
  • Physics NEET Syllabus
freeliveclasses_neetug
Download NEET 2023 question paper

Latest Notifications

  • NEET 2022 Answer Key – Link Here, Download PDF
  • Kerala Plus One Result 2022: DHSE first year results declared
  • RSMSSB
  • UPMSP Board (Uttar Pradesh Madhyamik Shiksha Parishad)
  • Digilocker
Company Logo

Unacademy is India’s largest online learning platform. Download our apps to start learning


Starting your preparation?

Call us and we will answer all your questions about learning on Unacademy

Call +91 8585858585

Company
About usShikshodayaCareers
we're hiring
BlogsPrivacy PolicyTerms and Conditions
Help & support
User GuidelinesSite MapRefund PolicyTakedown PolicyGrievance Redressal
Products
Learner appLearner appEducator appEducator appParent appParent app
Popular goals
IIT JEEUPSCSSCCSIR UGC NETNEET UG
Trending exams
GATECATCANTA UGC NETBank Exams
Study material
UPSC Study MaterialNEET UG Study MaterialCA Foundation Study MaterialJEE Study MaterialSSC Study Material

© 2023 Sorting Hat Technologies Pvt Ltd

Unacademy
  • Goals
    • AFCAT
    • AP EAMCET
    • Bank Exam
    • BPSC
    • CA Foundation
    • CAPF
    • CAT
    • CBSE Class 11
    • CBSE Class 12
    • CDS
    • CLAT
    • CSIR UGC
    • GATE
    • IIT JAM
    • JEE
    • Karnataka CET
    • Karnataka PSC
    • Kerala PSC
    • MHT CET
    • MPPSC
    • NDA
    • NEET PG
    • NEET UG
    • NTA UGC
    • Railway Exam
    • SSC
    • TS EAMCET
    • UPSC
    • WBPSC

Share via

COPY