question_answer 30)

  The proteins and lipids, essential for building the cell membrane, are manufactured by (a) endoplasmic reticulum (b) Golgi apparatus    (c) plasma membrane     (d) mitochondria

Answer:

  (a) The endoplasmic reticulum performs the following functions (i) It increases the surface area of the cytoplasm for various metabolic activities of the cell. (ii) It gives internal support to the colloidal matrix i.e., cytoplasm. (iii) it is associated with the synthesis, storage and transport of metabolic products. (iv) It helps in the formation of the cell plate and nuclear membrane during cell division. (v) Routh Endoplasmic Reticulum (RER) is associated with the synthesis of proteins. (iv) Smooth Endoplasmic Reticulum (SER) secretes lipids which along with proteins constitute cell membrane by a process called membrane biogenesis.