Biology Regents Practice Exam

Which statement best describes the characteristics a protein must have to function correctly?

1. A protein is a long chain of amino acids folded into a specific shape.

2. A protein is a long chain of simple sugars folded into a specific shape.

3. A protein is made of amino acids synthesized into a short, circular chain.

4. A protein is made of simple sugars synthesized into a short, circular chain.

The correct answer is: A protein is a long chain of amino acids folded into a specific shape.

The correct answer highlights that a protein is composed of a sequence of amino acids, which are linked together in a specific order to form a long chain. This chain then undergoes essential folding to achieve a three-dimensional shape, which is crucial for its function. The specific shape that a protein assumes is directly related to its particular function in biological processes. For instance, enzymes, which are a type of protein, need to have an appropriate conformation to bind to their substrates effectively. In contrast, proteins are not made of simple sugars, so options that describe proteins as being composed of sugars or implying circular structures do not accurately represent protein structure. The primary structure of a protein is linear, and its functionality arises from the complex arrangements formed by its folding and interactions with the environment. Thus, the correct answer encapsulates the fundamental aspects of protein structure and its importance in biological functions.