Question

Which of the following is not true of the enzyme-substrate interaction?

1) Many enzymes are extremely specific regarding a substrate.
2) Many enzymes cannot recognize a stereoisomer of their substrate.
3) Some enzymes accept any of a whole group of substrates.
4) Carboxypeptidase recognizes any of the amino acids from the carboxyl end of a polypeptide.
5) Cells are often able to carry out metabolic activity with only a handful of enzymes.

Answer 1

Enzymes typically bind to specific substrates or related molecules, and do not accept any of a whole group of substrates.

Step-by-step explanation:

The enzyme-substrate interaction is characterized by specificity, meaning that each enzyme is specific to a particular substrate. This means that option 3 is not true: some enzymes do not accept any of a whole group of substrates. Instead, enzymes typically bind to a specific substrate or a few related molecules that have a similar functional group or chemical bond. For example, carboxypeptidase recognizes and removes any of the amino acids from the carboxyl end of a polypeptide.

The statement 'Cells are often able to carry out metabolic activity with only a handful of enzymes' is not true, as cells require many enzymes for numerous metabolic processes. Enzyme specificity varies from enzyme to enzyme, with some having narrow substrate specificity and others like carboxypeptidase having a broader range.

The question, 'Which of the following is not true of the enzyme-substrate interaction?' pertains to the specificity of enzymes and their interaction with substrates. Among the options provided:

1. Enzymes are indeed often extremely specific regarding a substrate.
2. Many enzymes cannot recognize a stereoisomer of their substrate, thus showing specificity.
3. Some enzymes can accept any of a group of related substrates due to group specificity.
4. Carboxypeptidase is known to recognize nearly any amino acid from the carboxyl end of a polypeptide, thus showing broad specificity.
5. It is not true that cells can carry out metabolic activities with only a handful of enzymes since a multitude of distinct enzymes are required to catalyze the various chemical reactions in biological processes.

The incorrect statement is the fifth one. Cells typically require a wide variety of enzymes to carry out the complex web of metabolic activity. Answering the true/false part of the question, enzymes like carboxypeptidase can indeed have broad specificity and enzymes demonstrate various levels of specificity due to their active site's shape and chemical environment.