What happens to proteins during digestion?

During digestion, proteins undergo a process known as enzymatic hydrolysis, which breaks them down into their constituent amino acids. This process involves various enzymes, such as pepsin in the stomach and trypsin in the small intestine, that cleave the peptide bonds holding the amino acids together. The result is a series of smaller peptides and eventually free amino acids. These amino acids can then be absorbed through the intestinal wall into the bloodstream and transported to cells throughout the body, where they are utilized for protein synthesis and other vital functions.

The other processes described in the other choices do not accurately represent what occurs during protein digestion. For instance, proteins are not converted into lipids, nor are they absorbed directly without any chemical changes. Additionally, proteins do not convert into carbohydrates during digestion; instead, they are specifically broken down into amino acids for use by the body. Thus, enzymatic hydrolysis is the accurate representation of what happens to proteins during this process.