Final answer:
Human insulin is a protein molecule made up of two peptide chains and is essential for glucose metabolism. Recombinant DNA technology allows for the production of insulin identical to human insulin.
Step-by-step explanation:
Human insulin is a type of protein molecule. Insulin is a polypeptide hormone essential for the metabolism of glucose, and it is made up of two peptide chains, chain A and chain B, with 21 and 30 amino acids respectively. The primary structure of human insulin includes several disulfide bonds that are crucial for its function.
Recombinant DNA technology has allowed for the production of insulin that is identical to human insulin, known as recombinant insulin. This process involves inserting the human gene for insulin production into bacteria or yeast, which then produce the insulin protein.
Therefore, the correct option is a) Protein.