A Level Biology Practice Exam

Proteases are enzymes that primarily do what?

1. Catalyze the synthesis of proteins

2. Facilitate the absorption of vitamins

3. Break down proteins into amino acids

4. Promote the formation of DNA strands

The correct answer is: Break down proteins into amino acids

The correct response identifies the primary function of proteases, which is to break down proteins into amino acids. This process, known as proteolysis, is essential for numerous biological functions, including digestion, cellular signaling, and the regulation of protein turnover in the body. Proteins, composed of long chains of amino acids, need to be broken down into their individual components to be absorbed and utilized by the body for various metabolic processes. Proteases play a crucial role in digestion, particularly in the gastrointestinal tract, where they help convert dietary proteins into amino acids. These amino acids can then enter the bloodstream and be used to synthesize new proteins, support metabolism, and perform other vital functions. The other options refer to different biological processes: some enzymes are involved in synthesizing proteins, but that is not the role of proteases. Similarly, the absorption of vitamins is facilitated by other mechanisms and not directly through the action of proteases. Lastly, the formation of DNA strands involves enzymes known as DNA polymerases, rather than proteases. Thus, the clear and specific role of proteases is reflected in their ability to cleave proteins into amino acids.