Final answer:
The roles of proteins can be categorized as structural, contractile, transport, storage, and hormonal, with specific examples for each. Additionally, proteins are also classified based on structural complexity and their specific activities such as hydrolase or nucleotide binding.
Step-by-step explanation:
Functional Categories of Proteins
The roles played by proteins can be divided into several categories including:
Structural proteins such as collagen and keratin that provide support to various biological structures.
Contractile proteins like myosin and actin that are crucial for muscle movement.
Transport proteins such as hemoglobin that carry oxygen throughout the body.
Storage proteins that store essential nutrients, with examples being casein in milk and ferritin for iron storage.
Proteins that function as hormones like insulin, which regulates blood glucose levels.
There are other classifications of proteins based on their structural complexity which include simple, conjugated, and derived proteins. Furthermore, proteins may also be classified based on their activity, with examples being proteins with hydrolase activity, nucleotide binding, catalytic activity, and others.
To summarize, proteins have diverse roles which can be predicted with a certain degree of certainty based on their structure.