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With an exterior nuclear membrane, endoplasmic membranes are continuous.

The organelle, endoplasmic reticulum, that can be seen as present in almost all eukaryotic cells is an organelle that consists of two subunits – SER(smooth endoplasmic reticulum) and RER(rough endoplasmic reticulum). These organelles in rough endoplasmic reticulum form cisternae, a mesh of interconnected, flattened membrane-enclosed sacs and in SER exist as tubular structures. With an exterior nuclear membrane, endoplasmic membranes are continuous. However, these organelles are not present in spermatozoa or red blood cells. Golgi apparatus was discovered by Camillo Golgi, in the year 1950. It is also called a Golgi Complex or Golgi body,, membrane-bound organelle of eukaryotic cells (cells with clearly defined nuclei) that is made up of a series of flattened, stacked pouches called cisternae. The Golgi apparatus functions to  transport, modify, and pack proteins and lipids into vesicles for delivery to targeted destinations. It is placed in the cytoplasm next to the endoplasmic reticulum and near the cell nucleus. While many types of cell contain only one or several Golgi apparatus, plant cells can contain hundreds.

Golgi apparatus performs various important function inside the cell like: (i) The main function of Golgi apparatus is to carry out the processing of proteins generated in the endoplasmic reticulum. Golgi apparatus also transports protein to the different parts of the cell. (ii) The modification of cargo proteins is carried out by the Golgi enzymes present in membranous disks of cisternae. Modification of various substances is carried out by enzymes in cisternae with the help of processes like phosphorylation and glycosylation. (iii) Nucleotide sugars are imported by the Golgi apparatus from cytosol to carry out the glycosylation and phosphorylation processes. (iv) Polysaccharides are attached with proteins in order to form caru) One of the tasks of Golgi apparatus is carrying out the breakdown of proteins and formation of small, active fragments.bohydrates. (v) One of the tasks of Golgi apparatus is carrying out the breakdown of proteins and formation of small, active fragments. (vi) Sulfate groups are put to protein molecules in the Golgi apparatus. (vii) Adding phosphate molecules onto molecules of proteins is also a vital task carried out in the Golgi apparatus. (viii) Transfer of lipids around cells and creation of lysosomes are the vital functions carried out by Golgi apparatus. (ix) The Golgi body carries out the synthesis of proteoglycans . The proteoglycans are found in extracellular matrices of animal cells. (x) Carbohydrates are synthesized in the Golgi body. The process of carbohydrate synthesis involves production of polysaccharides and glycosaminoglycans (GAGs).

(a) Rough Endoplasmic Reticulum (b) Ribosomes (c) Cytosol (d) Smooth Endoplasmic Reticulum Answer: (d)

(a) Helps in cell-cell adhesion (b) Confer stability in proteins (c) Helps in proper folding of protein (d) Synthesis of membrane lipid Answer: (d)

(a) Lysosomes – involved in synthesizing amino acids (b) Microsomes – take part in photosynthesis (c) Centrosomes – Provides enzymes essential for digestion (d) Endoplasmic Reticulum – has a role in the formation of a new nuclear membrane while cell divides Answer: (d)

(a) Absent (b) Not functional (c) Poorly developed (d) Highly developed Answer: (c)

(a) Episome (b) Polysome (c) Microsome (d) Quantasome Answer: (c)

(a) Hormone synthesis (b) Protein synthesis (c) Release of calcium ions from muscle contractions (d) None of the above Answer: (c)

(a) Lysosome (b) Peroxisome (c) Mitochondria (d) ER Answer: (d)

(a) Protein Arms (b) Medial (c) Cis (d) Trans Answer: (c)

(a) Nucleic Acid (b) Carbohydrate (c) Protein (d) Lipid Answer: (d)

Q1. Define SER and RER Ans – The organelle, endoplasmic reticulum, that can be seen as present in almost all eukaryotic cells is an organelle that consists of two subunits – SER(smooth endoplasmic reticulum) and RER(rough endoplasmic reticulum). These organelles in rough endoplasmic reticulum form cisternae, a mesh of interconnected, flattened membrane-enclosed sacs and in SER exist as tubular structures. With an exterior nuclear membrane, endoplasmic membranes are continuous. However, these organelles are not present in spermatozoa or red blood cells. Q2. Who discovered Golgi Apparatus? Ans – Golgi apparatus was discovered by Camillo Golgi, in the year 1950. It is also called a Golgi Complex or Golgi body,, membrane-bound organelle of eukaryotic cells (cells with clearly defined nuclei) that is made up of a series of flattened, stacked pouches called cisternae. The Golgi apparatus functions to  transport, modify, and pack proteins and lipids into vesicles for delivery to targeted destinations. It is placed in the cytoplasm next to the endoplasmic reticulum and near the cell nucleus. While many types of cell contain only one or several Golgi apparatus, plant cells can contain hundreds.

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