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Vesicular transport

Vesicular transport. Vesicular transport. There are two basic types of vesicular transport: Endocytosis – Endo meaning ‘ within;inside ’. Exocytosis – Exo meaning ‘ outside;away from’. Sherwood, L (1997). Endocytosis.

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Vesicular transport

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  1. Vesicular transport

  2. Vesicular transport There are two basic types of vesicular transport: • Endocytosis – Endo meaning ‘within;inside’. • Exocytosis – Exo meaning ‘outside;away from’. Sherwood, L (1997)

  3. Endocytosis • Vesicles can be made during numerous processes that take place within the cell. Endocytosis is one type of vesicle formation. Sherwood, L (1997) states ‘In endocytosis, the plasma membrane surrounds the substance to be ingested, then fuses over the surface pinching off membrane enclosed vesicle.’ The contents of the ingested substance can then be either destroyed during phagocytosis or used efficiently. Amount of membrane decreases. • This process is used for particles too large to cross the hydrophobic plasma membrane. There are three major types, phagocytosis, pinocytosis, receptor mediated endocytosis. Sherwood, L (1997). Human Physiology. 3rd ed. USA: West Publishing Company. P26 Mcgraw hill companies inc

  4. Different types of endocytosis • Phagocytosis: whenmaterial taken into the cell is a bacterium or fragment of organic matter. • Pinocytosis: this process ofendocytosis is for any liquids that are entering the cell. • Receptor mediated endocytosis: specific molecules like low density lipoproteins or LDL are transported into the cell by binding to spec receptor on the plasma membrane and when enough LDL are bonded the plasma membrane will engulf the receptors and the LDL into a vesicle.

  5. Exocytosis • Exocytosis is in theory the reverse of endocytosis. ‘A membrane-enclosed vesicle formed within the cell fuses with the plasma membrane’ Sherwood, L (1997) and is then released. • Amount of membrane increases.

  6. Rates of endocytosis and exocytosis. • The rate at which endocytosis and exocytosis occurs must be the same. Sherwood, L (1997) supports this stating ‘endocytosis and exocytosis must be kept in balance to maintain a constant membrane surface area to cell volume.’ This is important due to the constant increase and decrease of the cell membrane occuring during to vesicular transport.

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