There are many types of intracellular proteins, though some types have been described more than others. This article will outline the main types of intracellular proteins and the roles they play in assisting or carrying out essential functions in our bodies.
Which Of The Following Is A Type Of Intracellular Protein
The answer is membrane protein. Membrane proteins are proteins that are embedded in the lipid bilayer of cellular membranes. These proteins perform a variety of functions, including serving as receptors for hormones, ions and other molecules that pass through the membrane.
Enzyme
Enzymes are a type of protein that catalyze biochemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates sufficient for life.
A large fraction of all enzymes in a cell are membrane-bound. However, some enzymes are soluble and found floating freely in the cell’s cytoplasm. Soluble enzymes are often involved in transport or temporary storage of products secreted by other cells. Some glycoproteins found on the exterior surface of animal cells function as enzymes called receptors, which bind to hormones and other signaling molecules to trigger physiological changes within the cell.
Enzymes are proteins that speed up chemical reactions. They work by lowering the activation energy needed to start a reaction. Enzymes are made of amino acids that have been folded into a specific shape. Both enzymes and antibodies have three-dimensional structures that allow them to recognize and interact with specific molecules in their environments.
Lipid
A lipid is a biomolecule that is soluble in nonpolar solvents. LIPIDS, or fat-soluble compounds, are hydrophobic and water insoluble. Lipids include fatty acids, glycerolipids, glycerophospholipids, sphingolipids, sterols and related molecules.
The main biological functions of lipids include energy storage (e.g., in the form of triglycerides), as structural components of cell membranes (e.g., phospholipids), as metabolic precursors (e.g., most notably as glycerol from which glucose can be synthesized) and as a means of storing chemical energy such as in fat bodies.
ipid-binding proteins can be divided into two groups:
1) The first group includes transmembrane proteins that are embedded in the lipid bilayer and have one or more hydrophobic amino acids exposed on the surface. These include sterols, fatty acids, sphingolipids, gangliosides and glycolipids. These proteins form complexes with lipids via hydrophobic interactions between the nonpolar groups of lipids and amino acids exposed at the surface of the protein.
2) The second group includes soluble intracellular proteins that bind to phospholipids or sphingolipids by hydrogen bonding between polar amino acid residues on the surface of these molecules and ionized phosphate groups on phosphatidylinositols or sphingosines within their binding sites.
Membrane protein
Membrane proteins are integral components of the plasma membrane, and they are found in all living organisms. These proteins can be transmembrane or peripheral membrane proteins.
Peripheral membrane proteins are located close to the surface of the cell and have one or more transmembrane domains. In contrast, transmembrane proteins cross the lipid bilayer in their entirety and may have multiple transmembrane domains.
Membrane proteins are vital for life because they regulate transport between two or more compartments within a cell. They also control signal transduction through their ability to bind to other molecules.
Nucleic acid
Nucleic acid is a biological polymer composed of nucleotides, which are simple organic compounds. The main functions of nucleic acids are as the unique units that carry genetic information and as components of DNA-dependent RNA polymerases. Nucleic acids also exist in both single- and double-stranded forms, and contain both deoxyribose and ribose sugar groups.
Nucleic acid is an organic compound made up of carbon, nitrogen, oxygen, hydrogen and phosphorus. It’s a polymer (a substance formed by joining many units), meaning it consists of many repeating subunits. In this case, the repeating subunits are nucleotides. A nucleotide consists of a phosphate group (PO4) attached to the 5′ carbon on the sugar deoxyribose; this is called deoxyribonucleic acid (DNA). The other common nucleotide is ribonucleic acid (RNA), which is made from ribose instead of deoxyribose.
Last Words
Out of the four listed, membrane proteins are definitely the most complicated to manufacture. There are numerous cellular membranes that must be purified for synthesis in an appropriate environment, along with added sugars and lipids that the proteins may bind to.
Membrane proteins are very difficult to produce single-produced from a heterologous host like E. coli because one of their domains is embedded in the lipid bilayer of the cellular membrane, meaning that it is not easily sequestered from the rest of the cell.
It is also true that there are processes other than protein interaction which can result in cell death, for instance when two similar protein complexes interact to cause protein aggregation under conditions which cells cannot combat. It is possible that multiple defects could arise together which lead to idiosyncratic cell death, but this is not well understood.