In humans, the products of anaerobic respiration are adenosine triphosphate (ATP), carbon dioxide and lactic acid. ATP is the molecule that provides energy to cells.
Two Types of Receptors. There are two types of acetylcholine receptors (AChR) that bind acetylcholine and transmit its signal: muscarinic AChRs and nicotinic AChRs, which are named after the agonists muscarine and nicotine, respectively.he muscarinic AChRs occur primarily in the CNS, and are part of a large family of G-protein-coupled receptors (G proteins), which use an intracellular secondary messenger system involving an increase of intracellular calcium to transmit signals inside cells.
Examples are the class of nuclear receptors located in the cell nucleus and cytoplasm and the IP3 receptor located on the endoplasmic reticulum. The ligands that bind to them are usually intracellular second messengers like inositol trisphosphate (IP3) and extracellular lipophilic hormones like steroid hormones. Some intracrine peptide hormones also have intracellular receptors.