Please, check out my video about enzymes :)
What are enzymes?
Enzymes refer to proteins that catalyze chemical reactions in our body. They are also called catalytic proteins. Enzymes speed up (or catalyze) chemical reactions by lowering the energy of activation (EA), which is the amount of energy needed to start a reaction. Enzymes exhibit tertiary structure.
How do enzymes work?
An enzyme binds to a substrate, forming enzyme-substrate complex. Thus, enzymes bind to the substrates when they are ''in action'', or when they catalyze a reaction. When an enzyme binds to a substrate, the shape of the enzymes alters as the substrate enters the active site, which is the place on the enzyme where the substrate can bind. Enzymes are substrate specific, which means that for instance enzyme A binds only to the substrate A etc.
However, enzymes often require assistance from substances called coenzymes and cofactors. These are substances that help enzymes in reaction catalysis, but cannot catalyze a reaction on their own. Coenzymes are organic substances, while cofactors are inorganic.
Competitive and noncompetitive (allosteric) inhibition
The enzymatic activity is highly controlled and regulated. This can be done in a number of ways. For instance, genes that code for a specific enzymes can be switched on and off. The enzymes that have already been produced are regulated by competitive and noncompetitive inhibition.
Competitive inhibition means that the substrate and a substrate-like substance (an inhibitor) ''competete'' for the active site of the enzyme. If the inhibitor binds to the enzyme, the enzyme won't work.
Noncompetitive inhibition, also known as allosteric inhibition, means that the inhibitor binds to another site of the enzyme (not to the active site). That causes the whole enzyme to undergo a change in its conformation, and the active site is changed. Thus, it's impossible for the substrate to bind to the enzyme.
What are enzymes?
Enzymes refer to proteins that catalyze chemical reactions in our body. They are also called catalytic proteins. Enzymes speed up (or catalyze) chemical reactions by lowering the energy of activation (EA), which is the amount of energy needed to start a reaction. Enzymes exhibit tertiary structure.
How do enzymes work?
An enzyme binds to a substrate, forming enzyme-substrate complex. Thus, enzymes bind to the substrates when they are ''in action'', or when they catalyze a reaction. When an enzyme binds to a substrate, the shape of the enzymes alters as the substrate enters the active site, which is the place on the enzyme where the substrate can bind. Enzymes are substrate specific, which means that for instance enzyme A binds only to the substrate A etc.
However, enzymes often require assistance from substances called coenzymes and cofactors. These are substances that help enzymes in reaction catalysis, but cannot catalyze a reaction on their own. Coenzymes are organic substances, while cofactors are inorganic.
Competitive and noncompetitive (allosteric) inhibition
The enzymatic activity is highly controlled and regulated. This can be done in a number of ways. For instance, genes that code for a specific enzymes can be switched on and off. The enzymes that have already been produced are regulated by competitive and noncompetitive inhibition.
Competitive inhibition means that the substrate and a substrate-like substance (an inhibitor) ''competete'' for the active site of the enzyme. If the inhibitor binds to the enzyme, the enzyme won't work.
No comments:
Post a Comment