Amino Acids, Proteins, and Enzymes

a 4-year-old boy, is having severe diarrhea, abdominal pain, and intestinal grow/ling 2 h after he eats. Noah is also underweight for his age. His mother makes an appointment for Noah to see Emma, his physician assistant. Emma immediately suspects that Noah may be lactose intolerant, which occurs due to an enzyme deficiency. 

Physician assistants can work in clinics, hospitals, health maintenance organizations, private practices, or take on a more administrative role that involves hiring new PAs and acting as a representative for the hospital and patient. 

Proteins and Amino Acids Amino Acids as Acids and Bases 

Proteins Primary Structure Proteins Secondary, Tertiary, and Quaternary Structures Enzymes 

The different functions of proteins depend on the structures and chemical behavior of amino acids, the building blocks of proteins. We will see how peptide bonds link amino acids and how the sequence of the amino acids in these protein polymers directs the formation of unique three-dimensional structures. 

All amino acids have a cential carbon atom attached to a carboxyl group, an amino group, and i hydrogen atom. The amino acids differ from one another only in the chemical nature of the side chain (R). 

The amino acids can be classified as either hydrophobic or hydrophilic, depending on the ease ith which their side chains interact with water. In general, proteins fold so that amino adds ith hydrophobic side chains are in the interior of the molecule where they are protected from water and those with hydrophilic side chains are on the surface. 

ACiD-BASE PROPERTIES OF AMINO ACIDS AND PROTEINS 

Amino acids and proteins have groups that can release and bind protons (H ) in other words, they have acid-base character. The groups with acid-base character can be generally represented in one of the two ways shown below. 

Structures with an amino group Acid (A) Base (B) 

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Chapter 16, Amino Acids, Proteins, and Enzymes, discusses amino acids, formation of peptide bonds and proteins, structural levels of proteins, enzymes, and enzyme action. Amino acids are drawn as their ionized forms in physiological solutions. Section 16.3 describes the primary level of protein structure. Section 16.4 describes the secondary, tertiary, and quaternary levels of proteins. Enzymes are discussed as biological catalysts, along with the impact of inhibitors and dena-turation on enzyme action. 

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