Chapter 15, Problem 15.6EP

(a)

Interpretation Introduction

Interpretation: To identify whether the statement “gastrin is a hormone released by stomach mucosa cells” relating to protein digestion is true or false.

Concept introduction: Proteins are natural biopolymers. Amino acids are the main building block of protein molecules. A large number of amino acids condense together to form a polypeptide chain. A large polypeptide chain is called protein. The digestion of dietary protein starts in the stomach and is completed in the small intestine. It does not start in the mouth because saliva present in the mouth does not contain an effective enzyme to break down the protein. The flow chart for protein digestion in the human body is as follows:

(b)

Interpretation Introduction

Interpretation: To identify whether the statement “approximately $90\%$ of protein digestion occurs in the small intestine” relating to protein digestion is true or false.

Concept introduction: Proteins are natural biopolymers. Amino acids are the main building block of protein molecules. A large number of amino acids condense together to form a polypeptide chain. A large polypeptide chain is called protein. The digestion of dietary protein starts in the stomach and is completed in the small intestine. It does not start in the mouth because saliva present in the mouth does not contain an effective enzyme to break down the protein. The flow chart for protein digestion in the human body is as follows:

(c)

Interpretation Introduction

Interpretation: To identify whether the statement “hydrochloric acid functions as a denaturing agent in the stomach” relating to protein digestion is true or false.

Concept introduction: Proteins are natural biopolymers. Amino acids are the main building block of protein molecules. A large number of amino acids condense together to form a polypeptide chain. A large polypeptide chain is called protein. The digestion of dietary protein starts in the stomach and is completed in the small intestine. It does not start in the mouth because saliva present in the mouth does not contain an effective enzyme to break down the protein. The flow chart for protein digestion in the human body is as follows:

(d)

Interpretation Introduction

Interpretation: To identify whether the statement “pancreatic digestive enzymes include carboxypeptidase and aminopeptidase” relating to protein digestion is true or false.

Concept introduction: Proteins are natural biopolymers. Amino acids are the main building block of protein molecules. A large number of amino acids condense together to form a polypeptide chain. A large polypeptide chain is called protein. The digestion of dietary protein starts in the stomach and is completed in the small intestine. It does not start in the mouth because saliva present in the mouth does not contain an effective enzyme to break down the protein.

The flow chart for protein digestion in the human body is as follows: