What is meant by Extracellular Matrix ECM Extracellular

What is meant by Extracellular Matrix? ECM

Extracellular Matrix v Extracellular matrix includes the interstitial matrix and the basement membrane. Interstitial matrix is present between various animal cells (i. e. , in the intercellular spaces).

The ECM is composed of an interlocking mesh of: Glycosaminoglycans (GAG) Fibrous proteins A) Glycosoaminoglycans: Large unbranched, polysaccharides chains. These polysaccharides Link to backbone of proteins forming proteoglycans. Glycosaminoglycans Distribution Hyaluronic acid Cartilage, synovial fluid, Skin. Chondroitin sulfate Cartilage, bone, skin Dermatan sulfate Skin, blood vessels, heart Heparan sulfate Basement membrane, lung arteries. Heparin Lung, liver, skin, mast cell granules. Keratan sulfate Cartilage, vertebral discs

Properties of GAG 1 - A high negative charge because one of the repeated units is N-acetylglucosamine or N-cetyl galactosamine is sulfated (SO 3 -), and most GAG has a second sugar uronic acid with a COO group. 2) Strongly hydrophilic behavior. 3) Retention of +ve ions (e. g. Na+) and water. 4) Covalent attachment with proteins to form proteoglycans B) Fibrillar (fibrous) proteins Collagen, fibrillin, elastin, fibronectin

1) Collagen give structural support to resident cells. It accounts for 90% of bone matrix protein content 2) Elastin give elasticity to tissues, allowing them to stretch when needed and then return to their original state. This is useful in blood vessels, the lungs, in skin 3) Fibronectins are proteins that connect cells with collagen fibers in the ECM, allowing cells to move through the ECM. 4) Fibrillin is a glycoprotein, which is essential for the formation of elastic fibers (are bundles of proteins (elastin)found in connective tissue

Muscle

Muscle types • Cardiac and skeletal muscles are "striated" in that they contain sarcomeres and are packed into highlyregular arrangements of bundles; smooth muscle has neither. • While skeletal muscles are arranged in regular, parallel bundles, cardiac muscle connects at branching, irregular angles (called intercalated discs).

Calcium pump • There is a very large transmembrane electrochemical gradient of Ca 2+ driving the entry of the ion into cells, yet it is very important for cells to maintain low concentrations of Ca 2+ for proper cell signalling; thus it is necessary for the cell to employ ion pumps to remove the Ca 2+. • An ion pump is a type of vacuum pump capable of reaching up to 10 -11 under ideal conditions

Structure of Myosin & actin in muscle

In human anatomy, the biceps brachii (simply biceps in common parlance) is a muscle located on the upper arm. The biceps has several functions, the most important being to rotate the forearm (supination) and to flex the elbow.

• In animals, extracellular matrix is composed of protein and polysaccharides. It can provide strength, such as cartilage that prevents joints from grinding against each other. It can provide structural support, such as the bone of skeletons. It can help organize cells, such as keeping tendons attached to bones. One last thing animal extracellular matrix can do is to assist will cell signaling to notify cells of changes in the environment. • The major proteins found in the extracellular matrix of animals serve two purposes: adhesion and structure. Adhesion is achieved by the proteins fibronectin and laminin. These two proteins attach cells to the extracellular matrix. Structure is achieved by the proteins collagen and elastin. These two proteins allow body parts to stretch and return to the original shape, such skin and inhaling air into the lungs. • The major polysaccharides found in vertebrates in the extracellular matrix are glycosaminoglycans (GAGs). GAGs are simply long chains of disaccharides. They tend to be negatively charged and thus get along well with water. When they are spat out from the cell to become part of the extracellular matrix, they take on a gel-like consistency, which makes them good for uses such as joint fluid and are also found in the skin and eyes.