Fiveable
Fiveable

or

Log in

Find what you need to study


Light

Find what you need to study

3.3 Environmental Impacts on Enzyme Function

5 min readdecember 27, 2022

Caroline Koffke

Caroline Koffke

Caroline Koffke

Caroline Koffke

Changes in the environment will affect the speed in which an enzyme functions. Proteins that are denatured lose their function, but sometimes, this can be reversed, called . It's like curling your hair. Though you curl it, it'll probably come back to its straight form in a few days. This is like renaturing a protein. However, in most cases, is nonreversible. Think of boiling an egg. Once you boil it, you can't unboil it.

There are multiple ways to denature a protein, and this topic is a FRQ-likely topic, so keep it in mind!

Temperature

is able to speed up and slow down reactions. Usually, when the is very cold, molecules are moving more slowly, and there are less opportunities for an enzyme and substrate to bump into one another. This slows the rate of the reaction and the effect of the enzyme.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-VKtWFyys1yhF.webp?alt=media&token=8bb14ecf-8527-4951-90bc-671c46409854

Image courtesy of Giphy.

When temperatures increase, molecules move more quickly and bump into one another more frequently. Because of this, the rate of a reaction increases as increases. That is until a specific threshold is hit. Once the becomes too high, the enzyme begins to denature. This occurs when the bonds that hold the into their 3-dimensional shape begin to break. Once the enzyme loses its shape, it loses its and is unable to function. Remember, structure is important for function, so if the structure is significantly altered, the protein will essentially malfunction.

Therefore, enzymes have an in which they function. For enzymes that work in the human body, they function best around our body , 97-99 degrees Fahrenheit, or around 37 Celsius. When the is too high or too low, the enzymes are not able to perform the life-sustaining reactions that they need to.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-3JOVI9PCWEli.png?alt=media&token=039b3620-6189-47ea-a3ae-270f82ea66d0

Image Courtesy of Pathwayz

pH

is a measurement referring to the number of present in a solution. When there are a lot of present, the solution has a low and is considered acidic. When there is a small number of present, the solution has a high and is considered basic. Every enzyme has an where it has its highest activity. A reduction or increase in outside of leads to the enzyme's activity to slow down and possible of the enzyme or substrate (leading to a substrate being unable to bind to an ).

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2FPH_Sensor_Channel.gif?alt=media&token=a84dc980-296d-40a1-8519-d4a182d55d07

Image courtesy of WikiMedia Commons.

Most enzymes work at an of 7, but it doesn't hold true for all enzymes. Some enzymes, such as work best at a of 2. This is because is a digestive enzyme that is found in the stomach, so it would make sense that this enzyme would work best at an acidic environment. Similarly, enzymes found in the function best at an acidic .

So why do enzymes get denatured at an incorrect ? It's because can be altered by the level, thus altering the structure of the protein (and you guessed it) and thus its function.

Concentration

If the of either is increased, the rate of the reaction should increase, as there is more opportunity for the two to meet. Ideally, both enzyme and substrate would increase, as if only one increases, the other acts as a . This means that the rate of the reaction is limited by the amount of either enzyme or substrate available. An example of a is below.

The of both enzymes and substrates can affect the overall rate of the reaction. A higher of both enzyme and substrate makes it more likely that the two will bump into one another. If either is in low supply, there will be fewer molecules available to start a reaction.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2Fcars.gif?alt=media&token=6af4dd6b-9cea-41a7-9eac-cee241320392

Image courtesy of Texas A&M University

As described above, there are a number of things that can alter the function of an enzyme, some of which can lead to . This process can either be temporary or permanent, depending on the magnitude of the damage. 

The human body maintains strict ranges of and in order to maintain the optimal functioning of enzymes. If the body enters a range that does not support enzyme functioning, such as very high , the enzymes in the body may denature, and the person could die. Thankfully, your body has a number of checks and balances in place to ensure that optimal ranges are continually met.

Inhibitors

don't denature the protein, but they do alter the structure of the protein. simply bind to the that the substrate was intended to bind to. This doesn't alter the protein, it simply makes it less likely for the substrate to bind to its enzyme.

On the other hand, alter the structure of the protein. do not necessarily bind to the of the enzyme, instead, they bind somewhere else. But because they bind somewhere else, the original gets altered, causing the intended substrate to not fit in.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-FH5X5hQ0Knts.jpeg?alt=media&token=b3005268-f139-45d5-bc61-8f9aa8ae04ab

Image Courtesy of BioNinja

This can decrease the . Both competitive and can be reversible or irreversible, depending on the situation.


Key Terms to Review (22)

Acidic Solution

: An acidic solution is a type of solution that has an excess of hydrogen ions (H+), giving it a pH less than 7.

Active Site

: The active site is the region on an enzyme where substrate molecules bind and undergo chemical reaction.

Amino Acids

: Amino acids are organic compounds that combine to form proteins. They are the building blocks of life and are vital for a number of functions in the body.

Basic Solution

: A basic solution is one that contains more hydroxide ions (OH-) than hydrogen ions (H+), resulting in a pH greater than 7.

Binding Site

: A binding site is a region on a protein or piece of DNA where a specific molecule, such as another protein or a small chemical compound, can bind. This interaction often results in a change in the function or activity of the protein.

Competitive Inhibitors

: These are molecules that bind to the active site of an enzyme, preventing the substrate from binding and thus inhibiting the enzyme's function.

Concentration

: Concentration refers to the amount of a substance (solute) present in a certain volume of solution.

Denaturation

: Denaturation is the process by which a protein loses its native shape due to the disruption of weak interactions within the molecule, often caused by changes in temperature or pH.

Enzyme Function

: The specific biochemical activity of an enzyme, often involving the conversion of a certain substance (substrate) into another (product).

Hydrogen Bonds

: Hydrogen bonds are weak interactions between two molecules caused by electrostatic attraction between a proton in one molecule and an electronegative atom in another.

Hydrogen Ions

: Hydrogen ions (H+) are single proton with no electrons and play crucial roles in chemical reactions, especially those involving acids and bases.

Inhibitors

: Inhibitors are substances that reduce the activity of enzymes, slowing down or even stopping certain reactions in the body.

Limiting Reagent

: The limiting reagent in a chemical reaction is the reactant that gets completely used up first and thus limits how much product can be formed.

Lysosome

: Lysosomes are organelles filled with enzymes that break down waste materials and cellular debris inside cells.

Noncompetitive Inhibitors

: Noncompetitive inhibitors are molecules that bind to an area other than an enzyme's active site, changing its shape so it can no longer effectively catalyze reactions with its normal substrates.

Optimal pH

: Optimal pH refers to the specific value at which a particular enzymatic reaction occurs at its maximum rate. It varies for different enzymes based on their environment and nature.

Optimal Temperature Range

: The optimal temperature range is the range of temperatures at which a biological system, such as an enzyme or organism, functions best.

Pepsin

: Pepsin is an enzyme in the stomach that breaks down proteins into smaller peptides during digestion.

pH

: pH is a measure of how acidic or basic a substance is. It ranges from 0 to 14, with 7 being neutral. Substances with a pH less than 7 are acidic, and those with a pH greater than 7 are basic (or alkaline).

Reaction Rate

: Reaction rate describes how quickly or slowly reactants turn into products in a chemical reaction.

Renaturation

: The process by which proteins or nucleic acids regain their native conformation after being denatured.

Temperature

: Temperature is a measure of the average kinetic energy of the particles in a system. It determines how much thermal energy these particles have.

3.3 Environmental Impacts on Enzyme Function

5 min readdecember 27, 2022

Caroline Koffke

Caroline Koffke

Caroline Koffke

Caroline Koffke

Changes in the environment will affect the speed in which an enzyme functions. Proteins that are denatured lose their function, but sometimes, this can be reversed, called . It's like curling your hair. Though you curl it, it'll probably come back to its straight form in a few days. This is like renaturing a protein. However, in most cases, is nonreversible. Think of boiling an egg. Once you boil it, you can't unboil it.

There are multiple ways to denature a protein, and this topic is a FRQ-likely topic, so keep it in mind!

Temperature

is able to speed up and slow down reactions. Usually, when the is very cold, molecules are moving more slowly, and there are less opportunities for an enzyme and substrate to bump into one another. This slows the rate of the reaction and the effect of the enzyme.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-VKtWFyys1yhF.webp?alt=media&token=8bb14ecf-8527-4951-90bc-671c46409854

Image courtesy of Giphy.

When temperatures increase, molecules move more quickly and bump into one another more frequently. Because of this, the rate of a reaction increases as increases. That is until a specific threshold is hit. Once the becomes too high, the enzyme begins to denature. This occurs when the bonds that hold the into their 3-dimensional shape begin to break. Once the enzyme loses its shape, it loses its and is unable to function. Remember, structure is important for function, so if the structure is significantly altered, the protein will essentially malfunction.

Therefore, enzymes have an in which they function. For enzymes that work in the human body, they function best around our body , 97-99 degrees Fahrenheit, or around 37 Celsius. When the is too high or too low, the enzymes are not able to perform the life-sustaining reactions that they need to.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-3JOVI9PCWEli.png?alt=media&token=039b3620-6189-47ea-a3ae-270f82ea66d0

Image Courtesy of Pathwayz

pH

is a measurement referring to the number of present in a solution. When there are a lot of present, the solution has a low and is considered acidic. When there is a small number of present, the solution has a high and is considered basic. Every enzyme has an where it has its highest activity. A reduction or increase in outside of leads to the enzyme's activity to slow down and possible of the enzyme or substrate (leading to a substrate being unable to bind to an ).

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2FPH_Sensor_Channel.gif?alt=media&token=a84dc980-296d-40a1-8519-d4a182d55d07

Image courtesy of WikiMedia Commons.

Most enzymes work at an of 7, but it doesn't hold true for all enzymes. Some enzymes, such as work best at a of 2. This is because is a digestive enzyme that is found in the stomach, so it would make sense that this enzyme would work best at an acidic environment. Similarly, enzymes found in the function best at an acidic .

So why do enzymes get denatured at an incorrect ? It's because can be altered by the level, thus altering the structure of the protein (and you guessed it) and thus its function.

Concentration

If the of either is increased, the rate of the reaction should increase, as there is more opportunity for the two to meet. Ideally, both enzyme and substrate would increase, as if only one increases, the other acts as a . This means that the rate of the reaction is limited by the amount of either enzyme or substrate available. An example of a is below.

The of both enzymes and substrates can affect the overall rate of the reaction. A higher of both enzyme and substrate makes it more likely that the two will bump into one another. If either is in low supply, there will be fewer molecules available to start a reaction.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2Fcars.gif?alt=media&token=6af4dd6b-9cea-41a7-9eac-cee241320392

Image courtesy of Texas A&M University

As described above, there are a number of things that can alter the function of an enzyme, some of which can lead to . This process can either be temporary or permanent, depending on the magnitude of the damage. 

The human body maintains strict ranges of and in order to maintain the optimal functioning of enzymes. If the body enters a range that does not support enzyme functioning, such as very high , the enzymes in the body may denature, and the person could die. Thankfully, your body has a number of checks and balances in place to ensure that optimal ranges are continually met.

Inhibitors

don't denature the protein, but they do alter the structure of the protein. simply bind to the that the substrate was intended to bind to. This doesn't alter the protein, it simply makes it less likely for the substrate to bind to its enzyme.

On the other hand, alter the structure of the protein. do not necessarily bind to the of the enzyme, instead, they bind somewhere else. But because they bind somewhere else, the original gets altered, causing the intended substrate to not fit in.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-FH5X5hQ0Knts.jpeg?alt=media&token=b3005268-f139-45d5-bc61-8f9aa8ae04ab

Image Courtesy of BioNinja

This can decrease the . Both competitive and can be reversible or irreversible, depending on the situation.


Key Terms to Review (22)

Acidic Solution

: An acidic solution is a type of solution that has an excess of hydrogen ions (H+), giving it a pH less than 7.

Active Site

: The active site is the region on an enzyme where substrate molecules bind and undergo chemical reaction.

Amino Acids

: Amino acids are organic compounds that combine to form proteins. They are the building blocks of life and are vital for a number of functions in the body.

Basic Solution

: A basic solution is one that contains more hydroxide ions (OH-) than hydrogen ions (H+), resulting in a pH greater than 7.

Binding Site

: A binding site is a region on a protein or piece of DNA where a specific molecule, such as another protein or a small chemical compound, can bind. This interaction often results in a change in the function or activity of the protein.

Competitive Inhibitors

: These are molecules that bind to the active site of an enzyme, preventing the substrate from binding and thus inhibiting the enzyme's function.

Concentration

: Concentration refers to the amount of a substance (solute) present in a certain volume of solution.

Denaturation

: Denaturation is the process by which a protein loses its native shape due to the disruption of weak interactions within the molecule, often caused by changes in temperature or pH.

Enzyme Function

: The specific biochemical activity of an enzyme, often involving the conversion of a certain substance (substrate) into another (product).

Hydrogen Bonds

: Hydrogen bonds are weak interactions between two molecules caused by electrostatic attraction between a proton in one molecule and an electronegative atom in another.

Hydrogen Ions

: Hydrogen ions (H+) are single proton with no electrons and play crucial roles in chemical reactions, especially those involving acids and bases.

Inhibitors

: Inhibitors are substances that reduce the activity of enzymes, slowing down or even stopping certain reactions in the body.

Limiting Reagent

: The limiting reagent in a chemical reaction is the reactant that gets completely used up first and thus limits how much product can be formed.

Lysosome

: Lysosomes are organelles filled with enzymes that break down waste materials and cellular debris inside cells.

Noncompetitive Inhibitors

: Noncompetitive inhibitors are molecules that bind to an area other than an enzyme's active site, changing its shape so it can no longer effectively catalyze reactions with its normal substrates.

Optimal pH

: Optimal pH refers to the specific value at which a particular enzymatic reaction occurs at its maximum rate. It varies for different enzymes based on their environment and nature.

Optimal Temperature Range

: The optimal temperature range is the range of temperatures at which a biological system, such as an enzyme or organism, functions best.

Pepsin

: Pepsin is an enzyme in the stomach that breaks down proteins into smaller peptides during digestion.

pH

: pH is a measure of how acidic or basic a substance is. It ranges from 0 to 14, with 7 being neutral. Substances with a pH less than 7 are acidic, and those with a pH greater than 7 are basic (or alkaline).

Reaction Rate

: Reaction rate describes how quickly or slowly reactants turn into products in a chemical reaction.

Renaturation

: The process by which proteins or nucleic acids regain their native conformation after being denatured.

Temperature

: Temperature is a measure of the average kinetic energy of the particles in a system. It determines how much thermal energy these particles have.


© 2024 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.


© 2024 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.