Question

describe the components of endomembrane system:nuclear envelope,endoplasmic reticulum,golgi appartaus,lysosomes,vacuoles,plasma membrane with their functions and structure

2-3 sentences each,in your own words please

not copy-paste from the internet

Answer 1

The endomembrane system consists of the different membranes, which are present in the cytoplasm within a eukaryotic cell. This endomembrane system includes the nuclear membrane, the endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, and cell membrane.

1) Nuclear envelope - It is a double membrane structure and made up of two lipid bilayer membranes, inner and outer membrane. It surrounds the nucleus and covers the genetic material in eukaryotic cells. It keeps the contents of the nucleus, known as nucleoplasm and separates from the cytoplasm of the cell. The nuclear pores of nuclear envelop allow content to move in and out of the nucleus.

2) Endoplasmic reticulum - ER is present in the cytoplasm in two forms as Rough ER , which is embedded with ribosomes and Smooth ER, which is free from ribosomes. Rough ER helps in synthesis and secretion of proteins and Smooth ER help in synthesis of lipids.

3) Golgi bodies - It is a complex of vesicles and folded membranes within the cytoplasm and involved in secretion and intracellular transport. It helps in packaging materials and delivered either to the intra-cellular targets or secreted outside the cell. Materials are packaged in the form of vesicles from the ER fuse with the cis face of the golgi apparatus and move towards the maturing face. It is essential site of formation of glycoproteins and glycolipids.

4) Lysosomes- These are membrane bound vesicular structures formed by the process of packaging in the golgi apparatus. The lysosomal vesicles have hydrolytic enzymes, which active at the acidic pH. These enzymes are able of digesting carbohydrates, proteins, lipids and nucleic acids.

5) Vacuole - Plants cells have a large vacuole. It stores water and waste products. It isolates hazardous materials. It has enzymes, which help in break down macromolecules and cellular components. It functions in water balance and used to store compounds such as toxins and pigments.

6) Plasma membrane - It is a biological membrane, which separates the interior of all cells from the outside surroundings. It consists of a lipid bilayer with embedded proteins. It protects the cell from its surroundings. It is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells.