Final answer:
Increasing the temperature and amount of substrates increases the rate of chemical reactions, while decreasing the amount of enzymes decreases the rate of reactions.
Step-by-step explanation:
An increase in the temperature would increase the rate of chemical reactions. When the temperature is increased, the reactant particles move faster, resulting in a greater frequency of collisions. Additionally, increasing the temperature also increases the percentage of collisions that are effective, leading to an increased reaction rate.
An increase in the amount of substrates would also increase the rate of chemical reactions. This is because when the concentration of the substrates is low, increasing their concentration leads to a greater number of collisions between reactant particles, thus increasing the rate of reaction.
On the other hand, a decrease in the amount of enzymes would decrease the rate of chemical reactions, as enzymes play a crucial role in speeding up reactions by lowering the activation energy required for a reaction to occur.