Enzymes are proteins that catalyze chemical reactions. Enzyme strain, or the distortion of an enzyme's shape, is a factor in enzyme activity and has been studied for decades. In this blog post we'll look at how strain affects the rate of reaction, what causes it and how scientists can model these effects mathematically.
Strain is an important factor in the activity of enzymes. It is a physical property of molecules and can be caused by interactions between molecules, such as those that occur in enzyme-substrate complexes. As you might have guessed from the name, strain refers to distortion in structures or pathways within a molecule. Strain can be caused by distortions in active sites or along the pathway or trajectory of catalysis (the process that gives rise to products).
Strain may prevent certain reactions from occurring altogether because they are too strained for their bonds to hold together. Alternatively, strain may cause reactions to happen more slowly because it takes longer for enough energy to be transferred by an enzyme's catalytic site before it can break its bonds with substrate molecules
A strained molecule is more likely to react than an unstrained molecule. The reason for this can be explained by the fact that strained molecules have more bond angles, which increases the number of reactive sites and in turn, increases the reaction rate. In addition to this, strained molecules also have longer bonds and shorter bonds than their corresponding unstrained counterparts. This makes it easier for these stressed out pieces of matter to break apart into smaller pieces upon collision with another molecule or some other particle (e.g., water).
Enzymes are proteins, which means they can be strained by extended or compact conformations. Stretching of the protein chain can cause strain, while compacting of the protein chain causes strain as well. These changes in conformation can increase reactivity and/or stability of an enzyme.
To understand strain, we first need to understand the concept of an ideal 2D shape. Idealized molecules are often represented as a series of planes that represent all possible orientations for each atom in the molecule. The difference between this representation and the actual 3D structure is called strain.
Enzyme strain can be caused by distortion in the enzyme's active site or along the pathway or trajectory of catalysis (movement from substrate to product).
The active site of an enzyme is the part of the molecule where a substrate binds in order to catalyze a reaction. The shape of the active site can be changed by substrate binding, which affects how well the enzyme can perform its function. This is because an enzyme's shape must be closely matched with its substrate in order to facilitate reactions that would otherwise not occur. Many enzymes are also strained by their substrates; this means that as soon as one molecule binds to its active site, subsequent molecules become increasingly difficult to bind due to steric hindrance (the physical obstacles caused by other molecules).
Strain is a measure of the internal pressure within an elastic material. The strain on an enzyme molecule is the amount of distortion it experiences while it carries out its normal enzymatic reactions.
Strain can be caused by distortion in the enzyme's active site or along the pathway or trajectory of catalysis. For example, Figure 1 shows two enzymes with different shapes: one has a deep pocket for binding to substrates; the other has a shallow pocket and must accommodate more bulky substrates like glucose-6-phosphate (G6P). As shown, these different shapes generate different degrees of strain on each enzyme during catalysis at their respective active sites.
Now that we understand what distortion is and why it occurs, let's move on to how it affects the rate of a reaction. The rate at which a reaction takes place depends on the energy barrier—this is the energy required for one molecule to convert into another. As you might have guessed, this means that there are two types of reactions: spontaneous reactions (ones where there is no energy barrier) and non-spontaneous reactions (ones with an energy barrier).
When an enzyme is in its native form, its active site is free from strain or distortion. This means that when substrate molecules bind here, they're able to move through their full range of motion without hindrance from other parts of the enzyme or anything else around them. This creates a very low-energy environment within which your substrates can react quickly and efficiently because they don't have far to go before they reach their transition state (the point at which they start changing into something else). But what happens if you put too much strain on this area?
Steric hindrance is the interference of one molecule with another molecule. This interference can be due to the size, shape, or charge of two molecules. The most common cause of steric repulsion is steric repulsion from large groups on one molecule that are too big to fit into smaller spaces on another molecule.
Steric hindrance is the tendency of atoms to occupy the same space. It’s easy to imagine how this could affect a molecule of enzyme: if there are many atoms nearby, then they can interfere with its ability to bind with its substrate. In other words:
Enzymes are proteins, and these molecules are very small. They're so small that they can't be seen with the naked eye. In fact, enzymes are thousands of times smaller than even a single cell!
What's more, enzymes aren't just made up of one type of protein: they're made up of many different types of proteins working together to control chemical reactions in living cells. This makes them extremely complex and hard to understand—but it doesn't mean we should give up hope! By using mathematical models and simulations, scientists have been able to predict how enzymes will react with other molecules with high accuracy. These simulations represent how an enzyme works as an electrical circuit (feedback loops), much like a thermostat controls the temperature in your house by monitoring changes in temperature through sensors placed around your home.
Strain and distortion are important considerations in enzymology because they affect both stability and reactivity.
Enzyme activity is determined by the following factors:
In summary, enzyme strain can affect activity in several ways. First, straining an enzyme's conformation may increase its chances of reacting with another molecule. Second, if the active site is strained due to a distorted substrate or distorted pathway/trajectory then binding that substrate will be more difficult and could affect reaction rates. Finally, steric hindrance can cause both strain on the enzyme molecule itself as well as increased distance between substrates which means there's less space for them to interact.