Which of the following statements concerning enzymes is false?
Most ate nonspecific and will work on any substrate speed up chemical reactions by
They speed lowering the activation energy
They are composed of protein
They are sensitive to temperature and pH
They are named after heir substrate or the type of reaction hey catalyze
The Correct Answer and Explanation is :
The false statement is:
“Most are nonspecific and will work on any substrate.”
Explanation:
Enzymes are highly specific biological catalysts that accelerate chemical reactions in living organisms. This specificity is central to their function. Here’s why the other statements are true:
- Enzymes speed up chemical reactions by lowering the activation energy:
Enzymes act by lowering the activation energy of a reaction, which is the energy required for the reaction to occur. By doing so, they allow reactions to proceed more quickly and efficiently at physiological temperatures. Enzymes do this by stabilizing the transition state of the reaction, facilitating the conversion of reactants to products. - Enzymes are composed of protein:
Most enzymes are made up of proteins, although some enzymes, called ribozymes, are made up of RNA. However, the vast majority of enzymes are proteins, and their structure is crucial to their function. The sequence of amino acids in the protein chain determines the three-dimensional shape of the enzyme, which is key to its ability to bind to specific substrates. - Enzymes are sensitive to temperature and pH:
Enzymes function optimally within a specific temperature and pH range. High temperatures or extreme pH levels can alter the enzyme’s structure (denaturation), causing it to lose its ability to bind with substrates and catalyze reactions effectively. This sensitivity to environmental conditions is critical for their proper functioning in different biological systems. - Enzymes are named after their substrate or the type of reaction they catalyze:
Enzymes are often named based on the substrate they act upon or the type of reaction they catalyze. For example, “lactase” is an enzyme that breaks down lactose, and “amylase” breaks down starch. The suffix “-ase” is commonly used for enzyme names.
Why the statement about nonspecificity is false:
Most enzymes are highly specific and will only work on particular substrates. This specificity comes from the enzyme’s active site, which is a region that binds to its substrate in a very specific way. This specificity is often compared to a “lock and key” model, where the enzyme (the lock) only fits the correct substrate (the key). While there are some exceptions (such as enzymes that can act on a range of similar molecules), enzymes generally exhibit a high degree of specificity, ensuring the efficiency and regulation of biochemical processes in living organisms.