Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

The primary structural function of proteins lies in their role in growth and repair. Proteins are essential macromolecules that contribute to the formation of various tissues in the body, including muscles, skin, and organs. They are made up of amino acids, which are the building blocks that create the structure necessary for cellular function and form. For instance, collagen, a type of protein, provides strength and structure to connective tissues, while keratin strengthens hair and nails. While proteins can provide energy if necessary, this is not their primary role. Instead, energy provision is generally more closely associated with carbohydrates and fats. The concept of genetic information storage pertains to nucleic acids like DNA and RNA rather than proteins. Additionally, although some proteins play a role in the immune response, protection from pathogens is not their primary function; this role is more characteristic of specific immune proteins, such as antibodies, rather than the general structural proteins in the body. Therefore, growth and repair highlight the fundamental structural role that proteins play in biological systems.