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P1 Structure and Function of Main Cell Components

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Structure and Function of Main Cell Components In this assignment I am going to describe the functions and structures of the plasma membrane itself and membrane bound organelles such as mitochondria, golgi apparatus, endoplasmic reticulum and other membrane bound structures. The cell membrane is also known as the plasma membrane; it is 7nm wide and separates the cell from its surroundings. It is mainly made up of two layers of phospholipids called the bilayer, which have hydrophilic heads (water loving) and hydrophobic tails (water hating). The plasma membrane is selectively permeable, controlling what substances can enter and leave the cell, allowing some molecules through and not others. Substances can move across the plasma membrane by diffusion, osmosis or active transport, through www.ofeducationcommission.com different proteins embedded in the membrane such as channel and carrier proteins. There are two types of transport, active transport and passive transport. ...read more.


It has a double membrane which creates compartments within the organelle, each membrane having a different function. The outer membrane is a phospholipid bilayer, which is permeable to small molecules such as nutrient molecules and adenosine triphosphate which is ATP. The inner membrane is folded over many times and is called cristae, they are the sites of ATP synthesis, the folds increase the surface area so more ATP can be produced. The inner membrane is permeableonly to oxygen, www.abcbodybuilding.com carbon dioxide and water. The fluid inside the mitochondria is called the matrix and contains enzymes, dissolved oxygen, carbon dioxide and water. The main function of the mitochondria is to synthesis energy for cellular activity, in the form of ATP by the process of aerobic respiration. There are two types of endoplasmic reticulum, rough and smooth. The endoplasmic reticulum is a series of flattened membrane bound sacs called cisternae. ...read more.


www.britannica.com Lysosomes have a simple structure; they are a round organelle, surrounded by a single membrane but with no clear internal structure. They contain digestive enzymes, which are kept separate from the cytoplasm by the surrounding membrane, and can be used to digest invading cells or to break down worn out components of the cell. Lysosomes can do this by fusing with vacuoles and dispensing their enzymes into the vacuoles, digesting their contents. The lysosomes are used for the digestion of www.uni-bielefeld.de molecules from phagocytosis, and autophagy. Phagocytosis is when a phagocyte moves towards the area of invasion and attaches itself to the microorganism's receptors e.g.: bacteria. The microorganism is then engulfed by the phagocyte in to a phagosome (vacuole). Inside the phagocyte are Lysosomes, which fuse with the phagosome and releases digestive enzymes. The digested contents are removed from the phagocyte by exocytosis. Autophagy is when a cell has an inadequate amount of nutrients in their extracellular fluids and begins to digest internal organelles, then recycling the organelles components to use elsewhere. ...read more.

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