Detailed Report on Enzyme Structure, Function, and Influencing Factors

This report provides a detailed overview of enzymes, starting with their structure as globular proteins with active sites and regulatory regions. It explains how the enzyme's structure, particularly its tertiary structure, is crucial for its function, especially in substrate binding. The report discusses activation energy and how enzymes reduce it to facilitate biological reactions. It evaluates the lock and key and induced fit models, explaining substrate enzymatic reaction. Furthermore, the report examines the effects of external factors such as temperature, pH, and substrate concentration on enzyme activity, highlighting optimum conditions for enzyme function. The document references relevant studies to support its explanations of enzyme mechanisms and influencing factors.

ENZYMES
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Structure of enzyme
•Enzymes are globular protein molecules in cells which work
as catalysts.
•It has an active site where substrate binds to the enzyme
and chemical reaction occurred (Villafañe et al. 2016) .
•Active site has specific structure due to tertiary structure of
protein
•It has a regulatory region where cofactors coenzyme that
regulate and alter the function of the enzyme.
Figure 1: enzyme structure
Source: (Villafañe et al. 2016) .

structure of enzyme related to their function
 The shape of the globular protein is
very sensitive in nature and it is vital to
the function of the enzyme.
 The tertiary structure provides the
active site of the enzyme. Amino acids
around the active site attach to the
substrate and hold the position for
reaction
(Wang, et al. 2015).
 Active site preciously matches the
shape of the molecule. Structure of
enzyme also influenced by the chemical
bonds that hold the structure
(Villafañe et al. 2016) .
Figure 2: enzyme
substrate and active site
interaction
Source : (Wang, et al.
2015).

ACTIVATION ENERGY
 Activation energy defined as the
minimum energy require to
successfully complete a reaction.
 The larger the activation energy, the
slower the reaction will be. Most of
biological reaction has huge
activation energy.
 Enzyme reduce the activation energy
of an reaction in a biological system
so that kinetic energy of most
molecule exceeds the activation
energy required for reaction.
Figure 3: graph of activation
Source: (Villafañe et al.
2016) .

Evaluation of lock and key and induced fit model
figure 4: Lock and key model.
Source :, (Mihut et al. 2017)
The phenomenon of single substrate enzymatic
reaction can be explained by Lock and key model
which was postulated by Emil fisher, 1894(t, Mihut et
al. 2017)
The lock is the enzyme and key is the substrate.
Only correct size substrate fits into the active site of
enzyme.
Lock and key states that there is no change of shape
only correct substrate attached to the enzyme.
figure 5: induced fit model
Source :, (Mihut et al. 2017)
•The induced fit model postulated by
daniel koshland in 1958.
•This theory states that when active
site comes in contact with proper
substrate, enzymes fold into the
shape of the substrate .

The effects of three external factors on enzyme activity.
Temperature, pH and substrate concentration are three
external factors that influence enzyme activity.
 Temperature: enzymes have an optimum
temperature at which they work. For mammalian
enzyme, the optimum temperature is 40 degree.
With optimum temperature, the rate of the reaction
increases.
 pH: enzymes have optimum p H that facilitate their
reaction. For a majority of enzyme it is 8. However,
gastric protease has an optimum temperature of 1.
 Substrate concentration: the rate of the reaction is
affected by substrate concentration. At higher
density, higher substrate collided with the active
site.
Figure 6: graph of
three external factors
Source: (Villafañe et
al. 2016) .

References
Mihut, A.M., Stenqvist, B., Lund, M., Schurtenberger, P. and
Crassous, J.J., 2017. Assembling oppositely charged lock and key
responsive colloids: A mesoscale analog of adaptive
chemistry. Science advances, 3(9), p.e1700321.
Villafañe, S.M., Heyen, B.J., Lewis, J.E., Loertscher, J., Minderhout, V.
and Arnold Murray, T., 2016. Design and testing of an assessment
instrument to measure understanding of protein structure and
enzyme inhibition in a new context. Biochemistry and Molecular
Biology Education, 44(2), pp.179-190.
Wang, R.K., Zhan, S.F., Zhao, T.J., Zhou, X.L. and Wang, C.E., 2015.
Positive selection sites in tertiary structure of Leguminosae
Chalcone isomerase. Genetics and Molecular Research, 14(1),
pp.1957-1967.