Endocytosis and exocytosis, Biology

Endocytosis and Exocytosis

Endocytosis is the process by which substances are brought into the cell from outside by formation of membrane bound vesicles. These extra cellular substances are enclosed in a small portion of plasma membrane which invaginates and pinches off to form an intracellular vesicle. The intake of fluids by.formation of vesicles is called as pinocytosis (pinein = drink). Pinocytosis is induced by the presence of appropriate concentrations of inducer molecules which can be proteins, amino acids or certain ions in the medium surrounding the cell. The ingestion of large particles by formation of larger vesicles is known as phagocytosis (phagein = to eat). The process of phagocytosis is associated with heterophagic activity of the lysosomes such as the destruction of worn blobd cells in the liver, spleen and bone marrow. Exocytosis is the reverse sequence where the membrahous intracellular vessicle fuses with plasma membrane and releases its content to the extracellular surroundings. The best understood form of , exocytosis is secretion by the cell. As you have studied earlier, Golgi apparatus plays an important role in the formation of cytoplasmic intracellular vesicles. The membrane of these vesicles is incorporated into plasma membrane and the vesicle's contents are discharged to the exterior.

Posted Date: 12/10/2012 3:06:05 AM | Location : United States

Related Discussions:- Endocytosis and exocytosis, Assignment Help, Ask Question on Endocytosis and exocytosis, Get Answer, Expert's Help, Endocytosis and exocytosis Discussions

Write discussion on Endocytosis and exocytosis
Your posts are moderated
Related Questions
Q. What is the autophagic intracellular digestion and why is this type of intracellular digestion intensified in an organism undergoing starvation? Autophagic intracellular dig

Define Nutritional Requirements and Recommended Allowances for Proteins and Amino Acids? The FAO/WHO Committee (1973) expressed the protein requirements in terms of egg or milk

Louping ill This is an infectious encephalomyelitis of sheep and man occurring during spring and summer when the vectors like ticks are active. It is reported from British Isl

What are the Advantages of Grains Diabetics should have more grains, beans and starchy vegetables every day. Whole-\ grain foods are nutritious and high in fiber, such as whol

For a sample containing both protein and nucleic acid, the absorbance measured at a particular wavelength will be the sum of contributions from both types of molecule. Using the pr

Q. How do the bacteria reproduce? Bacteria reproduce by binary fission termed as scissiparity. Some bacteria however present a kind of sexual reproduction transformation, conju

What is the phototropism? The Phototropism is the movement of plant structures in response to light. The Phototropism may be negative or positive. The Positive phototropism is

Which of the following statement is true regarding the replication of DNA strands? A. The products of replication include one double helix made exclusively of parental DNA and

Subphylum Crustacea Crustacea are mainly aquatic arthropods with gills for respiration. Cephalothorax has usually a carapace; appendages biramous but modified for several fun

Explain how a water molecule is produced when glucose and fructose undergo a condensation reaction. The glucose molecule releases a hydroxide ion, OH -, and the fructose molec