The way in which high temperatures reduce enzyme activity

In the third case, denaturation is not synchronous, because it is impossible for the temperature to be evenly distributed.

The second problem is that as long as the structure of the enzyme is not destroyed, that is, it is not inactivated, the denaturation is reversible.

The first question should be understood according to the first explanation, (not referring to the meaning of the TM value of nucleic acids).

The second problem is that it cannot be recovered. (As long as there is a decrease in activity, there is some enzyme denaturation, and it is difficult to recover activity after enzyme denaturation).

Within a certain temperature range,Enzyme activityStrengthens with increasing temperature. The temperature at which the activity of the enzyme is the highest is the optimal temperature of the enzyme. If the optimal temperature is exceeded, the activity of the enzyme gradually decreases or even stops.

High temperature denatures and inactivates the enzyme, and the activity cannot be restored, and low temperature only reduces the activity, and the activity can be restored without inactivation.

Enzyme activity moves thermally as the temperature increases.

Accelerates, increases the chance of molecular collisions, enzymatic reactions.

Rate increases. <>

1. Many of the polar groups in the enzyme molecule have different dissociation states at different pH, and only in a certain dissociation state is it the easiest to bind to the substrate or have the greatest catalytic activity, changing the substrate and coenzyme containing the dissociable group.

State of charge: Affects the affinity of the enzyme to it.

Spatial conformation influencing centers of enzyme activity.

2. Temperature and enzyme activity residual: each enzyme can only work within a certain range of temperature, the temperature when the enzyme shows maximum activity is called the optimal temperature of the enzyme, when it is lower than the optimal temperature, with the decrease of temperature, the activity does not decrease, and the catalytic efficiency of the enzyme is zero within a certain range, and the activity of the enzyme is inhibited at this time.

3. The temperature of the vertical bond panicle was restored to the most timely, and the activity of the enzyme gradually increased to the maximum. When the temperature is higher than the optimal temperature, the activity of the enzyme decreases rapidly as the temperature rises, and when it reaches a certain limit, it will be inactivated due to denaturation. At this time, even if the optimal temperature is restored, the activity of the enzyme will not be restored.

Reasons why enzyme activity increases with temperature over a certain temperature range:

As long as the temperature is raised, the reactant molecules gain energy, so that some of the molecules with lower energy become activated molecules, which increases the percentage of activated molecules, so that the number of effective collisions increases, so the reaction rate increases (the main reason). Of course, as the temperature increases, the rate of molecular motion accelerates, and the reaction accelerates as the number of molecular collisions of reactants per unit time increases.

Reasons why enzyme activity decreases with increasing temperature above the optimal temperature:

Enzymes and ribozymes that are chemically protein-like are easily denatured and inactive when exposed to heat. After exceeding the optimal temperature, with the increase of temperature, on the one hand, the enzymatic reaction speed is accelerated, but more importantly, it greatly reduces the concentration of the active enzyme, so the overall result is that the reaction speed decreases with the increase of temperature.

The mechanism of action of the enzyme is to accelerate the rate of chemical reaction by binding to the substrate, cooling will slow down the binding speed of the enzyme to the substrate, and the peptide chain in the enzyme will shrink at low temperature, and it is not easy to chimetry with the substrate.

The optimum temperature varies with the time of the reaction.

Enzymes are proteins or RNAs produced by living cells that are highly specific and catalytic to their substrates. The catalytic effect of enzymes depends on the integrity of the primary structure and spatial starvation structure of the enzyme molecule. Denaturation of enzyme molecules or depolymerization of subunits can lead to loss of enzyme activity.

Enzymes are biological macromolecules, with molecular masses of at least 10,000 or more, and the largest ones can reach millions.

Spatial structure

They are folded by the coiling of polypeptide chains to form a hole or fissure with a three-dimensional spatial structure on the surface of the enzyme molecule to accommodate the incoming substrate to bind to it and catalyze the transformation of the substrate into a product, and this region is called the active center of the enzyme.

However, the active center of an enzyme is only a small part of the enzyme molecule. The specificity of an enzyme-catalyzed reaction is actually determined by the binding group, catalytic group and its spatial structure of the enzyme active center.

The functional groups other than the active center of the enzyme are also necessary for the formation and maintenance of the slippery limb space conformation of the enzyme, so they are called essential groups other than the active center.