Understanding:
-Enzymes have an active site to which specific substrates bind
- Enzyme catalysis involves molecular motion and the collision of substrates with the active site
- Temperature, pH and substrate concentration can affect the rate of activity of enzymes
- Enzymes can be denatured
- Immobilized enzymes are widely used in industry
Enzymes: Globular proteins which acts as catalyst for biochemical reactions
Active sites and enzymes
Enzymes have an active site to which specific substrates bind
Enzymes are globular proteins that work as catalyst, meaning that they speed up Chemical reactions without being altered themselves. Substances thay enzymes convert into products are called subtrates. The substrate and the enzyme have polar regions that attract to each other.
Enzymes are found in all living cells and are also secreted by some cells to work outside.
-Enzymes have an active site to which specific substrates bind
- Enzyme catalysis involves molecular motion and the collision of substrates with the active site
- Temperature, pH and substrate concentration can affect the rate of activity of enzymes
- Enzymes can be denatured
- Immobilized enzymes are widely used in industry
Enzymes: Globular proteins which acts as catalyst for biochemical reactions
Active sites and enzymes
Enzymes have an active site to which specific substrates bind
Enzymes are globular proteins that work as catalyst, meaning that they speed up Chemical reactions without being altered themselves. Substances thay enzymes convert into products are called subtrates. The substrate and the enzyme have polar regions that attract to each other.
Enzymes are found in all living cells and are also secreted by some cells to work outside.
Enzyme Activity
Enzyme catalisis involves molecular motion and the collision of substrates with the active site
Active site: place of the surface of an enzyme to which substrate binds and which also catalyses the reaction
Enzyme activity is the catalisis of a reaction by an enzyme. There are three stages:
- The substrate binds to the active site of the enzyme
- While the substrates are bound to the active site they change into different Chemical substances, which are the products of the reactions.
- The products separate from the active site, leaving it vacant for substrates to bind again.
Note: a substrate molecule can only bind ot the active site if it moves very close to it. The coming together of a substrate molecule and an active site is known as a collision.
Enzyme catalisis involves molecular motion and the collision of substrates with the active site
Active site: place of the surface of an enzyme to which substrate binds and which also catalyses the reaction
Enzyme activity is the catalisis of a reaction by an enzyme. There are three stages:
- The substrate binds to the active site of the enzyme
- While the substrates are bound to the active site they change into different Chemical substances, which are the products of the reactions.
- The products separate from the active site, leaving it vacant for substrates to bind again.
Note: a substrate molecule can only bind ot the active site if it moves very close to it. The coming together of a substrate molecule and an active site is known as a collision.
Factors affecting enzyme activity
Temperature, pH and substrate concentration affect the rate of activity of enzymes.
Enzymes are affected by temperature in two ways:
- When a liquid is heated, the particles in it are given more kinetic energy; both enzyme and substrate molecules thus move around faster at higher temperatures, and risk of collision is higher
-When enzymes are heated, bonds in the enzyme vibrate more and the chance of the bonds to break is increased.
Ph: Most enzymes have an optimum pH at which their activity is the highest. If the ph is increased or decreased from the optimum, enzyme activity decreases and eventually stops altogether.
Substrate concentration: enzymes cannot catalyze reactions until the substrate binds to the active site. If the concentration of substrates is increased, substrate-active site collisions will take place more frequently and the rate at which the enzyme catalysis its reactions increases
Denaturation
Enzymes can be denatured.
Enzymes are proteins, and like other proteins their structure can be irreversibly affected by temperature and pH. If an enzyme is denatured, the active site is altered so the substrate can no longer bind.
Temperature, pH and substrate concentration affect the rate of activity of enzymes.
Enzymes are affected by temperature in two ways:
- When a liquid is heated, the particles in it are given more kinetic energy; both enzyme and substrate molecules thus move around faster at higher temperatures, and risk of collision is higher
-When enzymes are heated, bonds in the enzyme vibrate more and the chance of the bonds to break is increased.
Ph: Most enzymes have an optimum pH at which their activity is the highest. If the ph is increased or decreased from the optimum, enzyme activity decreases and eventually stops altogether.
Substrate concentration: enzymes cannot catalyze reactions until the substrate binds to the active site. If the concentration of substrates is increased, substrate-active site collisions will take place more frequently and the rate at which the enzyme catalysis its reactions increases
Denaturation
Enzymes can be denatured.
Enzymes are proteins, and like other proteins their structure can be irreversibly affected by temperature and pH. If an enzyme is denatured, the active site is altered so the substrate can no longer bind.
Immobilized enzymes
They are widely used in the industry. These types of enzymes are usually immobilized by attaching them to another material or into aggregations, so that the movement of the enzyme is restricted, for example, attaching enzymes to a glass surface or trapping them in an alginate gel.
One discovered use of an immobilized enzyme was that the extract of yeast, containing no yeast cells, would convert sucrose into alcohol. This opened the door to the use of enzymes to catalyze Chemical processes outside living cells.
They are widely used in the industry. These types of enzymes are usually immobilized by attaching them to another material or into aggregations, so that the movement of the enzyme is restricted, for example, attaching enzymes to a glass surface or trapping them in an alginate gel.
One discovered use of an immobilized enzyme was that the extract of yeast, containing no yeast cells, would convert sucrose into alcohol. This opened the door to the use of enzymes to catalyze Chemical processes outside living cells.