Video Transcript
Which of the following is an example of a regulatory protein? (A) Collagen, (B) adrenaline, (C) keratin, (D) actin, or (E) myosin.
One way to characterize different types of proteins is based on their function as
either a structural protein or a regulatory protein. Structural proteins are the building materials of the body. They often have repeating units and shapes that give them their mechanical strength
to provide structure to cells. The 3D shape of these proteins makes them ideal for forming fibers that can give
cells stability.
Examples of structural proteins include actin and myosin, which are two structural
proteins that are important components in muscle cells. We can therefore eliminate answer options (D) and (E), as these are not examples of
regulatory proteins.
Keratin is another example of a type of structural protein that is found
predominantly in hair, skin, and nails. Collagen is a structural protein responsible for healthy joints and skin elasticity
or stretchiness. We can therefore eliminate answer choices (A) and (C) as well.
Regulatory proteins, on the other hand, are proteins that regulate different
processes and activities within the organism. They have specific 3D shapes that often need to be compatible with other molecules or
proteins to perform their functions and may not have repeating units like structural
proteins.
There are several different categories of regulatory proteins. Enzymes, like peptidase or amylase, help speed up chemical reactions. Antibodies and cytokines play an important role in the immune system. Hormones are chemical messengers that can affect gene expression and functioning of
their target cells. Some examples of hormones include insulin, glucagon, adrenaline, and
testosterone.
We can now answer our question. An example of a regulatory protein is option (B), adrenaline.
