What is the purpose of enzymes in any biological reaction? They allow for a process that would never have occurred without the enzyme. B) They raise the activation energy and speed up the reaction. C) They lower the activation energy and speed up the reaction. D) They provide energy for the reaction.
The correct answer and explanation is:
The correct answer is C) They lower the activation energy and speed up the reaction.
Enzymes are biological catalysts that accelerate chemical reactions within living organisms. A catalyst is a substance that speeds up a reaction without being consumed in the process. Enzymes play a crucial role in metabolic pathways, allowing reactions to occur at a much faster rate than they would without the enzyme. This is vital for maintaining life, as many biochemical reactions would occur too slowly to sustain life processes without the assistance of enzymes.
Enzymes work by lowering the activation energy, which is the energy required to start a reaction. They achieve this by providing an alternative reaction pathway that has a lower energy threshold. This is possible because enzymes have a unique active site where specific substrates bind, forming an enzyme-substrate complex. The shape and chemistry of the active site are precisely suited to the substrate, and when the substrate binds to the enzyme, it stabilizes the transition state, making it easier for the reaction to proceed.
By lowering the activation energy, enzymes not only speed up the reaction but also allow the reaction to occur at normal biological temperatures and pH levels, where they can be most effective. Without enzymes, many biochemical reactions in the body would be too slow to support life processes like digestion, energy production, and cellular function.
Enzymes do not provide energy for the reaction, nor do they change the overall energy balance of the reaction. They simply make it easier for the reaction to occur by providing a more efficient pathway. Once the reaction is complete, the enzyme remains unchanged and can catalyze additional reactions.