Biology

Cell Envelope Definition Cell envelope is a combination of the cell membrane, cell wall, and an outer membrane if it is present. Usually, this envelope…

Lipid Bilayer Definition Lipid bilayer is a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward…

Acetylcholine Definition Acetylcholine is a substance that is released at the junction between neurons and skeletal muscle fibers, at the nerve endings of the parasympathetic…

Lipids Srtucture, Properties and Function Lipid – Lipids are biological molecules that are insoluble in water, but are soluble in non-polar solvents, meaning that they…

About Lipid Definition Lipids are any of a large group of organic compounds that are oily to the touch and insoluble in water. Lipids include…

Goblet Cell Definition Goblet cells are any of the specialized epithelial cells, such as those found in the mucous membrane of the stomach, intestines, and…

Plastid Definition Plastid is an organelle found in the cells of plants, green algae, red algae, and certain other protists. Like mitochondria, plastids have an…

Neurotransmitter Definition Neurotransmitter is a chemical substance that is produced and secreted by a neuron and then diffuses across a synapse to cause excitation or…

Histamine Definition Histamine is an organic compound found widely in animals and plants that in humans and other mammals is released as part of the…

Gastric Glands Definition Gastric gland is the basic secretory unit of the stomach and contains a variety of component cells located in characteristic locations. It…

Salivary Gland Definition Salivary gland is a gland in terrestrial animals that secretes saliva. In humans, three pairs of large glands, which include the parotid…

Gallbladder Definition Gallbladder is a small, pear-shaped muscular sac in most vertebrates in which bile is stored. The gallbladder is located beneath the liver and…