Anatomy and Physiology P1

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(P1) Outline the functions of the main cell components

Every individual possess billions of cells in their body but not only is the human body functional With cells but also contains tissues, organs and systems which is what the human body is made up of. The cell carries out vast numbers of chemical reactions which processes in order to make up the essence of life (Moonie N, Aldworth C, Billingham M & Talman H ,2012). Cells are usually grouped together with other cells carrying out particular tasks (Moonie N, Aldworth C, Billingham M & Talman H, 2012); the cells that are grouped are known as the tissues. Tissues are commonly grouped together to form an organ. Then finally the organs are responsible for the functions in the human body which are called systems. Cells vary in size and shapes which are easier to observe with a microscope either using an electron microscope which are useful to see the details of the cell. Not all types of cells are exactly like others but they do have the same basic parts. In general all cells have three main parts; an animal cell has three features in common which are the cell membrane, the nucleus and organelles. Cell membrane

Each cell has a cell membrane it is also known as the plasma membrane which is a fragile, transparent outer boundary which forms around the cell to separate them from the surrounding environment (Marieb,E N, (2012).), the membrane allows what comes in and out of the cell. The structure of the cell membrane consists of two layers of phospholipids (fatty substances) with large protein molecules inserted completely into the layers. The phospholipids are an important component of the cell membrane as they form a lipid bi-layer which has a head that is electrically charged and hydrophilic (Waugh, A & Grant, A ,2012.) which means it is water soluble and arranges itself facing the outer surfaces of the membrane, it also has a tail which has no electrical charge and his hydrophobic (Waugh, A & Grant, A ,2012). this means it afraid of water which then the tail faces the other way and then the tail forms a central water- repelling layer. The lipid bi-layer is semi-permeable, allowing only certain molecules to diffuse across the membrane. The fluid surrounding the cells is called the tissue fluid and the cytoplasm is both watery environments next to the phosphate heads (Moonie N, Aldworth C, Billingham M & Talman H ,2012). Plasma membrane proteins function in several different ways. Many of the proteins play a role in the selective transport of certain substances across the phospholipid bilayer, either acting as channels or active transport molecules. Others function as receptors, which bind information-providing molecules, such as hormones, and transmit corresponding signals based on the obtained information to the interior of the cell. Membrane proteins may also exhibit enzymatic activity, catalysing various reactions related to the plasma membrane A semipermeable membrane is a membrane that allows certain types of molecules to pass through it but does not allow others to pass through. Semipermeable membranes work within the body cells to control what substances can and cannot pass into the cells. By serving as a barrier between the interior and the exterior of the cell, the semipermeable membrane protects the cell from foreign bodies that could be harmful. Other semipermeable membranes, usually working with an artificial membrane, are used for specific functions such as water desalination and purification. Other terms used to refer to a semipermeable membrane are "selectively permeable membrane," "partially permeable membrane" or "differentially permeable membrane." All of these terms simply refer to the fact that the semipermeable membrane controls what molecules can and cannot pass through it, based on characteristics such as the molecules' size, chemistry, solubility or other specific properties. Molecules pass through the semipermeable membrane...
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