Globular proteins are proteins that have a compact, spherical shape. They are usually soluble in water and play important roles in cellular processes such as enzymes, hormones, and antibodies. Fibrous proteins are long, thin proteins that are insoluble in water and provide structural support in tissues such as hair, nails, and tendons.

A globular protein is called so because of its spherical or globular shape. The term “globular” refers to the overall shape of the protein, which is roughly spherical, and the term “protein” refers to the fact that it is a biomolecule made up of amino acids.

The three-dimensional structure of a globular protein is usually highly folded and compact, with the hydrophobic amino acid residues on the inside and the hydrophilic amino acid residues on the outside. This compact and folded structure is stabilized by a combination of hydrogen bonds, ionic bonds, disulfide bonds, and other types of non-covalent interactions.

Globular proteins are typically water-soluble and play many important roles in the body, such as enzymes, transport proteins, and hormones. The spherical shape of globular proteins is also important in their function, as it allows them to interact with other biomolecules in a specific and controlled manner.

The main difference between globular proteins and fibrous proteins is their overall shape and function.

Shape: Globular proteins have a roughly spherical or globular shape, while fibrous proteins have an elongated or fibrous shape.

Function: Globular proteins are typically water-soluble and perform a wide variety of functions in the body, such as enzymes, transport proteins, and hormones. Fibrous proteins, on the other hand, are typically insoluble in water and have a more structural role in the body, such as providing support and strength to tissues and organs.

Amino acid sequence: The amino acid sequence of globular proteins is usually irregular, with regions of alpha-helix and beta-sheet secondary structure interspersed throughout the protein. Fibrous proteins, on the other hand, have a more regular amino acid sequence, with long stretches of alpha-helix or beta-sheet secondary structure.

Solubility: Globular proteins are typically water-soluble due to their polar and charged amino acid residues on the surface of the protein, while fibrous proteins are typically insoluble in water due to their non-polar amino acid residues.

In summary, while both globular and fibrous proteins are important biomolecules with specific functions in the body, their shape, amino acid sequence, solubility, and function are different.

The compact, spherical shape of globular proteins allows them to easily bind with other molecules and perform specific functions, such as catalyzing reactions in enzymes, transmitting signals in hormones, or recognizing and neutralizing foreign invaders in antibodies.

The long, linear structure of fibrous proteins allows them to provide strength and stability in tissues, as well as forming networks to help maintain the structure of cells and tissues.

Common examples of globular proteins include enzymes, such as lactase and catalase, hormones, such as insulin and testosterone, and antibodies, such as immunoglobulin G.

Common examples of fibrous proteins include keratin in hair and nails, collagen in skin and connective tissues, and elastin in elastic tissues.

Globular proteins can interact with other molecules by binding with them through specific, non-covalent bonds. Fibrous proteins generally do not interact with other molecules in the same way as globular proteins, as they do not have the same level of complexity and diversity in their structures.

Changes in temperature or pH can cause structural changes in both globular and fibrous proteins, disrupting their function and stability. For example, elevated temperatures can cause denaturation of proteins, leading to the loss of their native structure and function.

Globular and fibrous proteins play crucial roles in cellular processes, including metabolism, signaling, and structural support. Understanding their structures and functions is essential for understanding many aspects of biology, from human physiology to the workings of cells and tissues.