Mindblown: a blog about philosophy.

Enzyme Substrate Complex Definition The enzyme substrate complex is a temporary molecule formed when an enzyme comes into perfect contact with its substrate. Without its substrate an enzyme is a slightly different shape. The substrate causes a conformational change, or shape change, when the substrate enters the active site. The active site is the area…

Energy Pyramid Definition An energy pyramid (sometimes called a trophic pyramid or an ecological pyramid) is a graphical representation, showing the flow of energy at each trophic level in an ecosystem. The width of each bar represents the units of energy available within each trophic level; the height is always the same. The flow of energy moves…

Endothelium Definition The endothelium is a layer of cells that lines the blood vessels and lymph vessels of the body. Although you probably don’t know it exists, your epithelium is vital to keeping you alive! It includes all blood-and-lymph carrying vessels, including the chambers of the heart and the glomeruli, or “filters,” of the kidneys.…

Endosymbiotic Theory Definition Endosymbiotic theory is the unified and widely accepted theory of how organelles arose in organisms, differing prokaryotic organisms from eukaryotic organisms. In endosymbiotic theory, consistent with general evolutionary theory, all organisms arose from a single common ancestor. This ancestor probably resembled a bacteria, or prokaryote with a single strand of DNA surrounded by a plasma membrane.…

Endoskeleton Definition An endoskeleton is a skeleton found within the interior of the body; it provides structural support and protection for the internal organs and tissues of an organism. Endoskeletons can take several forms, and can differ in complexity, shape and function, depending on the requirements of the animal. Most vertebrates have an endoskeleton, which is comprised…

Endoplasmic Reticulum Definition The endoplasmic reticulum (ER) is a large organelle made of membranous sheets and tubules that begin near the nucleus and extend across the cell. The endoplasmic reticulum creates, packages, and secretes many of the products created by a cell. Ribosomes, which create proteins, line a portion of the endoplasmic reticulum. Endoplasmic Reticulum…

Endoderm Definition The endoderm is an embryonic germ layer that gives rise to tissues that form internal structures and organs. The endoderm is found in both vertebrate and invertebrate embryos, and is responsible for the formation of the gut and associated organs. Endoderm cells are present in both diploblasts and triploblasts. Endoderm Formation Germ layers…

Endocytosis Definition Endocytosis is the process of actively transporting molecules into the cell by engulfing it with its membrane. Endocytosis and exocytosis are used by all cells to transport molecules that cannot pass through the membrane passively. Exocytosis provides the opposite function and pushes molecules out of the cell. Like all systems in the human…

The endocrine system is made up of a series of organs within the body, including the brain, pancreas, ovaries, testicles, and thyroid gland. These organs secrete hormones into the blood stream to regulate many of the body’s functions. Many of these glands help to regulate each other, such as by the pituitary gland secreting thyroid…

Definition The endocrine system is a collection of ductless glands that produce hormones and secrete them into the circulatory system. Endocrine glands work without ducts for carrying secretions towards target organs. Instead, hormones can act as chemical messengers for a large number of cells and tissues simultaneously. Overview The endocrine system consists of many glands,…