High School Biology What is a glycoprotein? Examples of interferon . And so on

It can be divided into three categories according to the mode of existence: 1. Soluble glycoproteins, which exist in intracellular fluid, various body fluids and mucus secreted by luminal glands. Plasma proteins are glycoproteins except albumin.

Soluble glycoproteins include enzymes (e.g., nucleases, proteases, glycosidases), peptide hormones (e.g., chorionic gonadotropin, luteinizing hormone, thyroid-stimulating hormone, erythropoietin), antibodies, complement, and certain growth factors, interferons, statins, lectins, and toxins.

2. Membrane-bound glycoprotein, whose peptide chain is composed of hydrophobic peptides and hydrophilic peptides. Hydrophobic peptides can be one or several and embedded in the membrane-lipid bilayer through hydrophobic interactions. Hydrophilic peptides are exposed outside the membrane.

The glycans are attached to hydrophilic peptides and have strict directionality. On the surface of the plasma membrane, the sugar chains are always facing outward; In the intracellular membrane is generally towards the cavity surface. Membrane-bound glycoproteins include enzymes, receptors, lectins, and carrier proteins.

These glycoproteins are often involved in cell recognition and can serve as surface markers or surface antigens for specific cells or cells at specific stages.

3. Structural glycoproteins are insoluble macromolecular glycoproteins in the extracellular matrix, such as collagen and various non-collagen glycoproteins (fibronectin, laminin, etc.). Their function is not only to support, connect and buffer the structural components of the extracellular matrix, but more importantly, to participate in cell recognition, adhesion and migration, and to regulate cell proliferation and differentiation.

Oligosaccharide chain usually refers to an aggregate composed of 2 10 monosaccharide groups linked by glycosidic bonds. The oligosaccharide chains of glycoproteins are mostly branched. Because there are two configurations of the terminal carbon (allogeneous carbon) atom of monosaccharides, and there are multiple hydroxyl groups in the monosaccharide molecule that can form glycosidic bonds, the diversity of glycan structure exceeds that of polynucleotides and peptide chains.

Sufficient recognition information can be stored in the sugar chain structure, which plays a decisive role in molecular recognition and cell recognition. The physiological functions involved in glycoproteins include coagulation, immunity, secretion, endocytosis, material transport, information transmission, nerve conduction, regulation of growth and differentiation, cell migration, cell homing, wound repair and regeneration. The glycans of glycoproteins are also involved in maintaining their peptide chains in the biologically active natural conformation and stabilizing the peptide chain structure, and endowing the whole glycoprotein molecule with specific physicochemical properties (such as lubricity, viscoelasticity, heat inactivation, protease hydrolysis and frost resistance, etc.).

Excerpt from Encyclopedia).

Structural proteins --- cytoskeleton.

Carrier proteins --- hemoglobin.

Immune proteins --- antibodies.

Catalytic proteins --- pepsins.

Hormone proteins --- insulin.

Constituent proteins --- important building blocks of cells.

And then there's the one that is digested and energized.

Cellulose is sugar. Protein is dehydrated and condensed into peptides by amino acids, which are then coiled and folded into proteins. Most of the enzymes and some of the hormones are proteins.

Cellulose and sugar belong to the category of sugar....Some hormones are proteins, and most enzymes are proteins.