Search results
Results from the WOW.Com Content Network
Protein–protein interactions regulate enzymatic activity, control progression through the cell cycle, and allow the assembly of large protein complexes that carry out many closely related reactions with a common biological function. Proteins can bind to, or be integrated into, cell membranes.
Membrane proteins perform a variety of functions vital to the survival of organisms: [2] Membrane receptor proteins relay signals between the cell's internal and external environments. Transport proteins move molecules and ions across the membrane. They can be categorized according to the Transporter Classification database.
Proteins are needed for many cellular functions, such as repairing damage or directing chemical processes. Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum. Their main function is to convert genetic code into an amino acid sequence and to build protein polymers from amino acid monomers.
The human genome, categorized by function of each gene product, given both as number of genes and as percentage of all genes. [7] Proteins may also be classified based on their cellular function. A widely used classification is PANTHER (protein analysis through evolutionary relationships) classification system. [7]
Every cell consists of cytoplasm enclosed within a membrane; many cells contain organelles, each with a specific function. The term comes from the Latin word cellula meaning 'small room'. Most cells are only visible under a microscope. Cells emerged on Earth about 4 billion years ago. All cells are capable of replication, protein synthesis, and ...
Plasma proteins, sometimes referred to as blood proteins, are proteins present in blood plasma. They serve many different functions, including transport of lipids, hormones, vitamins and minerals in activity and functioning of the immune system. Other blood proteins act as enzymes, complement components, protease inhibitors or kinin precursors.
Every carrier protein, especially within the same cell membrane, is specific to one type or family of molecules. GLUT1 is a named carrier protein found in almost all animal cell membranes that transports glucose across the bilayer. This protein is a uniporter, meaning it transports glucose along its concentration in a singular direction. It is ...
While some receptors are cell-surface proteins, others are found inside cells. For example, estrogen is a hydrophobic molecule that can pass through the lipid bilayer of the membranes. As part of the endocrine system, intracellular estrogen receptors from a variety of cell types can be activated by estrogen produced in the ovaries. [citation ...