ENZYME BIOCHEMISTRY INDUCED FIT & LOCKED KEY MODEL [GROUP 2] MLT 435 NUR AIDA ADRIANA BINTI AZIZAN NUR ALISHA SHOFI BINTINORAZIZOLIRAMAN NUR ERLEESA NAJWA BINTI ZULKIFLY NOOR SYAZWANI BINTI ALIAS WAN NOR MAHIRAH BINTI WAN DAUD
SUBTOPICS PAGES NUMBER Definition Induced Fit and Lock Key Model 3 Comparison (Similarities & Difference) 4 Mechanism of Induced Fit Model 5 Mechanism of Lock Key Model 6 Importance and Function of Induced Fit and Lock Key Model 7 References 8 TABLE OF CONTENTS 2
INDUCED FIT MODEL THEORY The enzyme's active site can be induced in a small changes to allow the substrate fully bind to the active site and achieve the optimal fit . LOCK AND KEY MODEL Lock - enzyme THEORY Key - substrate The enzyme's active site and the substrate are perfectly fit. There is no conformational changes of the active site to allow the substrate binds to it. The analog of specificity : Karki, P. (10 September, 2022). Induced Fit Model- Definition, Mechanism, Advantages. Retrieved from The Biology Notes: https://thebiologynotes.com/induced-fit-model-definition-mechanism-advantages/#what-isinduced-fit-model Karki, P. (3 August, 2022). Lock and Key Model- Mode of Action of Enzymes. Retrieved from The Biology Notes: https://thebiologynotes.com/lock-and-key-model-mode-of-action-of-enzymes/#lock-and-key-model 3
Induced Fit Model Lock Key Model vs Daniel Koshland Proposed Emil Fischer 1958 Year 1894 Definition Induced conformational change in active site Perfect binding of specific substrate to specific enzyme Conformational Shape changes No shape change Flexible structure Enzyme A rigid structure like a lock Active site shape Non-complementary to substrate Complementary to substrate Substrate Binding with variety of related substrate Single substrate binding Nature of binding Flexible binding of substrate Substrate binds tightly to the active site Transitionstate Explain Does not explain Enzyme-catalyzed reaction Substrate binding to the active site of an enzyme Enzyme-substrate complex formation Example Enzyme-protein, antigenantibody, and hormonereceptor binding : -Enzyme is amylase, substrate molecule is starch Catalysed by yeast hexokinase : -Adenylate kinase 4
Mechanism of Induced Fit Model Image retrieved from: https://jackwestin.com/resources/mcat-content/enzyme-structure-andfunction/induced-fit-model-of-enzymes The other name of substrate is called the reactant of molecule. The active site changes its conformation when the substrates are present to provide for a better fit between the active site and the substrate. By extension, this means that enzymes are very highly specific to the reaction they catalyst. It is specific because the enzyme's active site can be properly aligned by the substrate, which then enables the enzyme to carry out its catalytic function. The substrates will bind to the enzyme at the active site. The enzyme will changes shape slightly as the substrates bind to the enzyme, which is why it is called induced fit. The enzyme-substrate complex is formed. Finally, the products will be leaving from the active site enzyme. The active site will be free to bind to another substrates. 5
Lock Key Model is the second model that describes the enzyme-substrate interaction. The active site of the enzyme serves as the 'Lock', while its substrate serves as the 'Key'. The shape of the enzyme active site is complementary to the shape of the substrate. Therefore, the enzyme active site can hold the substrate closer to the enzyme by producing an unusable intermediate compound known as the Enzyme-Substrate Complex. The shape of the enzyme active site complements the shape of the substrate that causes active site of the enzyme can hold the substrate closer to the enzyme by producing an unusable intermediate compound, the enzyme-substrate complex. The near closeness allows the biological reaction to proceed and causes the subsequent dissociation of the enzymecomplex, the enzyme and the products are produced. The lock and key model eliminated the necessity for separate catalytic group for the enzyme function. The enzyme static active site is represented by a single entity in the lock and key model. Mechanism of Lock Key Model 6 Image retrieved from: https://alevelbiology.co.uk/notes/biological-catalysts-enzymes/
7 IMPORTANCE AND FUNCTION OF MODEL Lock and key model Induced fit model Shape and chemistry of the substrate and the shape and chemistry of the active site on the enzyme are complementary. This indicates that the enzyme and substrate form a complex when the substrate enters the active site and fits perfectly. Only a specific lock can be opened by a unique, distinct key is similar to how a specific substrate can only fit into a specific active site of an enzyme. This is significant in how proteins interact between molecules and is crucial in how drugs interact. To help comprehend the fundamental ideas behind enzyme specificity, size, and their function in the body. The exact complementary shape, chemistry, or alignment of the enzyme and substrate is not present at first; rather, substrate binding induces this alignment at the active site. Thus will help the enzyme break down easier. Maximises the reaction's enzyme's capacity to catalyse as there are shifting of binding site to fit with substrate The positions, sequences, structures, and characteristics of the amino acid residues within the active site produce a very particular chemical environment. To help figuring out how dynamic enzyme-substrate interactions work, how the active site affects specificity and how it works. Retrived from Models of Action | BioNinja. (n.d.). https://ib.bioninja.com.au/higher-level/topic-8- metabolism-cell/untitled-6/models-of-action.html
REFERENCES MLT 435 8 Ahmad, D. A. (2020, December 25). Ahmad Coaching. Retrieved from Lock and Key Model vs Induced Fit Model: https://www.ahmadcoaching.com/2020/12/lock-andkey-model-vs-induced-fit-model.html Karki, P. (10 September, 2022). Induced Fit Model- Definition, Mechanism, Advantages. Retrieved from The Biology Notes: https://thebiologynotes.com/induced-fit-model-definition-mechanismadvantages/#what-is-induced-fit-model Karki, P. (3 August, 2022). Lock and Key Model- Mode of Action of Enzymes. Retrieved from The Biology Notes: https://thebiologynotes.com/lock-and-key-model-mode-ofaction-of-enzymes/#lock-and-key-model Lakna. (27 November, 2019). What is the Difference Between Induced Fit and Lock and Key - Pediaa.com. Pediaa.com. https://pediaa.com/what-is-the-differencebetween-induced-fit-and-lock-and-key/ Lewis T, Stone WL. Biochemistry, Proteins Enzymes. [Updated 2022 Apr 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554481/ Schmitt, Emmanuelle, et al. (18 December, 2009) “Switching from an Induced Fit to a Lock and Key Mechanism in an Aminoacyl-TRNA Synthetase with Modified Specificity.” Journal of Molecular Biology, vol. 394, no. 5, 18 Dec. 2009, pp. 843–851, Retrieved from www.ncbi.nlm.nih.gov/pmc/articles/PMC2801061/ Westin, Jack. “Induced Fit Model of Enzymes - Enzyme Structure and Function - MCAT Content.” Jack Westin, 23 Feb. 2020, Retrieved from jackwestin.com/resources/mcatcontent/enzyme-structure-and-function/induced-fit-model-ofenzymes#:~:text=The%20induced%2Dfit%20model%20states.