Their Shapes Fit Snugly Together.
Active sites of enzymes (where the substrates fit in) are substrate specific, and are complementary to the shape of the molecule (substrate). In this way, enzymes can only act on a specific substrate, since that is the only shape that it will accommodate in the active site.
Many times enzymes have multiple active sites that allow for many simultaneous reactions. For example, it's possible to have a fourth of the number of enzymes as substrate molecules, but the enzyme may have four active sites, resulting in one active site per substrate molecule.
Active sites are located in enzymes inside the cells. this is where the substrate binds itself to the enzyme and the reaction takes place.
Substrate molecules bind to enzymes at specific active sites thus activating the enzyme. The enzyme then reduces the activation energy required for a bond to form between the substrate molecules, so bonding (the reaction) proceeds at a faster rate.
Enzymes have specific active sites that match the shape and charge of their substrate molecules. This specificity allows enzymes to catalyze specific chemical reactions. Substrate binding induces a conformational change in the enzyme to more effectively convert substrate molecules into products.
active sites
A molecule that binds to an enzyme is usually referred to as a substrate. Substrates are the molecules on which enzymes act to catalyze a biochemical reaction. Upon binding to the enzyme's active site, substrates undergo a chemical transformation to form products.
Concentration of substrate can affect enzyme activity by impacting the rate of enzyme-substrate complex formation. At low substrate concentrations, enzyme activity may be limited by the availability of substrate molecules. However, at high substrate concentrations, enzyme activity may become saturated as all enzyme active sites are occupied.
Enzymes have specific active sites that bind to substrates in a complementary manner based on their shape and chemical properties. This specificity allows enzymes to interact with only certain substrates or closely related ones that can fit into their active sites. Any mismatches in shape or chemical properties may prevent effective binding and inhibit the enzyme's activity.
Enzymes are proteins, which are made up of amino acids. Each enzyme has a different sequence of amino acids and changing even one amino acid will mean that the tertiary structure of the enzyme will be lost and so will it's active site. As enzymes are substrate specific, only a certain substrate will bind to its active site, due to its amino acid sequence determining the shape of the active site.
The model you are referring to is the lock-and-key model of enzyme-substrate interaction. This model proposes that enzymes have specific active sites that perfectly fit the substrate, similar to how a lock fits a key. This precise fit allows for the formation of the enzyme-substrate complex and subsequent catalysis of the reaction.
Enzymes have specific active sites that can only bind to complementary substrates, based on size, shape, and chemical properties. The binding of substrates to the active site induces a conformational change in the enzyme that stabilizes the transition state for the reaction with that particular substrate. Additionally, enzymes may undergo induced fit where the active site reshapes to better accommodate the specific substrate.