Explain the effects of the following on enzyme activity: ➢ Temperature: Temperature influences the bonds that occur between the R groups of the amino acids and are responsible for the 3D shape of a protein. • At cold temperatures, the bonds of the tertiary structures become rigid, preventing induced fit. In addition, molecules move slower at lower temperatures decreasing the collisions between enzymes and substrates. As a result, the reaction rate is lower. • At high temperatures, the bonds of the tertiary structures are disrupted and break due to increased energy. As a result, the enzyme loses its 3D shape (denaturation) and cannot bind substrate. • Optimal Temperature — temperature at which enzyme activity is the greatest.
➢ Ph: pH also affects the bonds that determine the 3D shape of an enzyme. • Changes in pH cause protons (H+) to be added or removed to. From R groups of amino acids which disrupts the ionic bonds between R groups. As thw bonds are disrupted, the shape of the enzyme os altered and the protein is denatured.
➢ salinity: Changes in salt concentration can add or remove cations (+) and anions (-) which disrupts the attractions between charged amino acids. As a result the protein loses its shape and is denatured.
➢ Enzyme Concentration: As enzyme concentration increases, reaction rate increases until a certain point when the reaction rate levels off and becomes constant.- More enzymes —> more frequently collide with substrate molecules. -Substrate molecules become the limiting factor as not all enzyme molecules can find and bond to substrate molecules.
As substrate concentration increases, reaction rate increases until a certain point when the reaction rate levels off and becomes constant. - More substrate molecules —> more frequently collide with enzyme molecules. - At a certain substrate concentration all enzymes have their active site engaged —> enzyme is saturated —> maximum rate of reaction.