Proteins

Question 1

Define the various classes of amino acids.

Answer 1

Nutritionally, amino acids are divided into 3 groups—essential, nonessential, and semi-essential. Semi-essential amino acids are synthesized by the body but are designated essential during periods of stress. Essential is gained from the diet, non-essential is synthesised in the body.

Question 2

Define the terms ‘primary structure’, ‘secondary structure’, ‘tertiary structure’ and
‘quaternary structure’.

Answer 2

Primary = sequence of amino acids
secondary = folding of these amino acids into different structures.
tertiary = overall 3D structure of a polypeptide
quaternary = is many 3D structures together, aka many amino acid chains

Question 3

Describe the functions of proteins.

Answer 3

It helps repair and build your body’s tissues, allows metabolic reactions to take place and coordinates bodily functions.

Question 4

Discuss the particular properties that the possession of quaternary structure may confer on a protein.

Answer 4

Quaternary structure is critical to the function of such proteins, as it determines how the subunits come together to form an active protein complex, which may exhibit properties and functions not found in the individual subunits.

Question 5

Compare the structures and functions of fibrous proteins with those of globular
proteins.

Answer 5

Fibrous proteins are structural in nature, which means they help maintain cell shape by providing a scaffolding or a framework. On the other hand, globular proteins are functional, which means they carry out a specific biological function in the body.