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The Importance of Biological Molecules.

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The Importance of Biological Molecules I will discuss the importance of biological molecules, and in the interest of brevity I will limit this to carbohydrates, lipids and protein. Lipids basically are the "bag" around the cell structure, proteins are the mechanics to control cellular processes, and the carbohydrates are the cell's energy source. A plasma membrane primarily consists of lipids in terms of molecules, but also protein and carbohydrates. This is because of a lipid's biological properties. A lipid has a hydrophilic head and a hydrophobic tail, thus forms a bilayer. The lipids line up tails inwards and heads out. The phospholipid bilayer is a barrier keeping the contents inside a cell or "vesicle", but also water out of the cell. "This phospholipids bilayer is studded with proteins, polysaccharides and other lipids. It is described as a fluid mosaic model." Although water and the water-soluble molecules can not usually pass through a lipid membrane, lipids and lipid soluble molecules can. ...read more.


"It is a globular protein so it has a distinctive tertiary structure. Like all enzymes, it functions because part of its molecule forms what is called an active site. RNA molecules will fit into this site where they are broken down into their components." The structure of an enzyme is key to its efficiency. Without the chemical bonds between amino acids that maintain this structure, the protein would be denatured and useless. The structure and shape of an enzyme has to be just right; if the enzyme molecule is deformed, even slightly, it will not function. Only a few amino acids are actually involved in the active site the others then make up the correct bulk and structure of the enzyme. Collagen is a fibrous protein, which is insoluble and has important structural functions. Collagen is the basic structure of connective tissue, tendons and sheath of muscle, but also the organic structure of bone. Haemoglobin is the red coloured pigment in red blood cells. ...read more.


They help animals disarm potentially harmful foreign materials that enter the body. This is done in two different ways. One way is that the foreign body targeted and bonded with a protein's active site identifying it to structures on the cell surface as something to be digested and destroyed. The second is when a protein engulfs the foreign body and as an enzyme breaks it down digesting it. Glycogen is the primary animal storage form of carbohydrates, and starch is the primary storage for plants. "In most animals, carbohydrates provide a quickly available reservoir of energy. Glycogen is stored in the liver and muscles as a stable chain of glucose and is then broken down when energy is needed." Monosaccharides are an important source of energy in respiration but also are an immediate product in the biochemical pathways of respiration and photosynthesis. This is because a monosaccharide is so simple it makes energy transference easy. For structural purposes polysaccharides may be used. Cellulose is very important to the rigid yet flexible structure of a plant cell wall. The cellulose's properties allow the plant cell wall to keep it shape. ...read more.

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