The smooth endoplasmic reticulum lacks ribosomes and functions in lipid synthesis but not metabolism, the production of steroid hormones, and detoxification. Certain cells must secrete substantial amounts of proteins and enzymes for use in the body, and as such, they have much rougher endoplasmic reticulum than other cells. Ribosomes are macromolecules that aid in protein synthesis, specifically during translation (i.e. Prove you're human, which is bigger, 2 or 8? They are rough or granular ER and smooth or agranular ER. 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). © 2020 Science Trends LLC. Functions of the smooth endoplasmic reticulum : Synthesis, storage, and transport of lipids. Smooth endoplasmic reticulum (SER) is an organelle that is likely to be involved in sequestering calcium. About 50% of the total membrane surface … The main function this organelle is protein and lipid synthesis as well as storage of certain ions and molecules required for energy. It is present near the cell periphery. Some proteins will remain in the membrane of the ER, while others will be transferred to the ER where they will float around. The smooth endoplasmic reticulum lacks ribosomes. rough ERb. The smooth endoplasmic reticulum forms transition vesicles to transfer molecules produced in the rough ER to the Golgi complex. Functions • The smooth ER-Carbohydrate and lipid synthesis • Smooth ER acts as a storage organelle. Lysosomes also play a role in the immune system, as they can digest and degrade foreign or harmful particles from the outside of the cell. Rough ER: Protein synthesis for outside the cell; Smooth ER: Lipid production and detoxification ; What is the difference between Cytoplasm and Cytosol ? for glycerol phospholipids, ceramide and cholesterol. Cells that secret these products, usually cells of the skin oil glands, have an excess of smooth endoplasmic reticulum. Smooth endoplasmic reticulum (SER) is an organelle that is likely to be involved in sequestering calcium. ER without ribosomes is called smooth endoplasmic reticulum and contains enzymes for lipid biosynthesis, especially the synthesis of phospholipids and steroids. The functions of the smooth endoplasmic reticulum also differ. It specializes in lipid synthesis, steroid hormone production, and detoxification. Function: produces and modifies proteins Located next to the nucleus Called the rough endoplasmic reticulum because it has ribosomes on the surface. This is an electron microscope image showing part of the rough endoplasmic reticulum in a plant root cell from maize. It is often referred to as the post office of the cell, tagging, sorting, and sending lipids and proteins to the correct place. The rough endoplasmic reticulum is also responsible for creating phospholipids, which make up the membranes of cells. The endoplasmic reticulum is divided into two major section: smooth endoplasmic reticulum and rough endoplasmic reticulum. Many of these products are made for and exported to other organelles. L Rough endoplasmic reticulum: organelle composed of membrane enclosed stacks of membranes continuous with the nuclear envelope and studded with ribosomes functioning in protein synthesis m. Smooth endoplasmic reticulum: organelle composed of membrane enclosed stacks of membranes continuous with the nuclear envelope and the site for lipid and carbohydrate metabolism as well as … There are two types of endoplasmic reticulum, rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). Structure . The vesicles that exit the endoplasmic reticulum will move towards a structure called the Golgi body, where they will transfer their lipids and proteins over to the organelle. Left: The relationship between the nucleus, rough, and smooth ER. Smooth endoplasmic reticulum: organelle composed of membrane enclosed stacks of membranes continuous with the nuclear envelope and the site for lipid and carbohydrate metabolism as well as detoxification. Function: lipid and carbohydrate synthesis. The Endoplasmic Reticulum. The structure of the endoplasmic reticulum enables it to fulfill its functions, and as such both, the rough endoplasmic reticulum and the smooth endoplasmic reticulum have different functions and different appearances. ER without ribosomes is called smooth endoplasmic reticulum and contains enzymes for lipid biosynthesis, especially the synthesis of phospholipids and steroids. It then is fused with the lysosome, where the digestive enzymes break down the pathogen rendering it harmless. smooth ERc. The conversion of DNA to RNA is called transcription but does not involve rough ER. Endoplasmic reticulum has two major regions: smooth endoplasmic reticulum and rough endoplasmic reticulum. Via the attached ribosomes, rough endoplasmic reticulum synthesizes proteins via the translation process. Desiree Hunt Organelle Major Function Mitochondrion ATP production, cellular respiration Smooth Endoplasmic Reticulum Lipid synthesis Rough Endoplasmic Reticulum Protein synthesis Golgi Apparatus Sorts proteins produced by ribosomes Cytoskeleton structural support Free Ribosomes in Cytosol Produce proteins Peroxisome Catalyze oxidation reactions Lysosome Breakdown macros Cell Type … What is the transitional endoplasmic reticulum? A. smooth endoplasmic reticulum B. rough endoplasmic reticulum C. golgi bodies D. lysosomes. All rights reserved. There’s a rough endoplasmic reticulum and a smooth endoplasmic reticulum. Cytosol is the cellular fluid inside the cell. It is present near the cell periphery. Golgi bodies. An organelle is a sub-unit within a cell that has a specialized function. CELLS NEED THE ROUGH AND THE SMOOTH. The rough ER (endoplasmic reticulum) function involves the assembly of proteins and the transportation of those assembled ready proteins to where they will be used by the body. ER is an important organelle which participates in synthesis, folding, modification, and transport of proteins. Create your account. - Definition & Function, Eukaryotic and Prokaryotic Cells: Similarities and Differences, Hypertonic Solution: Definition, Effect & Example, Smooth ER: Definition, Functions & Structure, High School Biology: Homework Help Resource, SAT Subject Test Biology: Practice and Study Guide, NY Regents Exam - Living Environment: Test Prep & Practice, UExcel Pathophysiology: Study Guide & Test Prep, SAT Subject Test Biology: Tutoring Solution, High School Biology: Homeschool Curriculum, AP Biology Syllabus Resource & Lesson Plans, High School Biology Curriculum Resource & Lesson Plans, Biology 101 Syllabus Resource & Lesson Plans, Biological and Biomedical That's great to hear! The organelle called ‘endoplasmic reticulum’ occurs in both plants and animals and is a very important manufacturing site for lipids (fats) and many proteins. Also, this network increases the area for storage of key enzymes and their products. It is also associated with tubules continuous with the edges of the saccules and vesicles. Smoother sections of the endoplasmic reticulum can also be found in the rough endoplasmic reticulum and they function as places the vesicles can leave the rough endoplasmic reticulum through, they are fittingly called the transitional endoplasmic reticulum. The main function of the smooth ER is to make cellular products like hormones and lipids. The endoplasmic reticulum is divided into two major section: smooth endoplasmic reticulum and rough endoplasmic reticulum. The rough ER sends newly made proteins to the Golgi apparatus where they are modified and packaged for delivery to various locations within or outside of the cell. Problem: Lipid synthesis occurs in which eukaryotic organelle?a. The rough ER sends newly made proteins to the Golgi apparatus where they are modified and packaged for delivery to various locations within or outside of the cell. Connected with the nucleus and golgi Apparatus to form proteins. The main difference between Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER), is that RER is studded with membrane-bound ribosomes, while SER lacks this organelle. There are two types of ER: smooth and rough. This is where most protein synthesis occurs. A. smooth endoplasmic reticulum B. rough endoplasmic reticulum C. golgi bodies D. lysosomes. 1-15 and 1-16). Some ribosomes float freely in... Our experts can answer your tough homework and study questions. On the cytoplasmic side of its membrane, almost all the lipid constituents of the membranes are synthesized: cholesterol, phospholipids, glycolipids, etc. Smooth endoplasmic reticulum is where lipid synthesis occurs, and where the organelle handles toxic substances within the cell. A cell structure that forms a maze of passageways in which pro… Where is the ER located? Smooth Endoplasmic Reticulum Definition. The smooth endoplasmic reticulum, or smooth ER, is an organelle found in both animal cells and plant cells. Science Trends is a popular source of science news and education around the world. Other chains of molecules can be removed or added to the proteins, and phosphate groups can be used as a tag to indicate their correct destination. The endoplasmic reticulum is part of the endomembrane system, which refers to the group of organelles whose responsibility is to create, package, modify, and transport proteins and lipids around the cell and outside of the cell. The part of the pathogen that the cell engulfs is separated from the plasma membrane and encased in a structure referred to as a phagosome. ISSN: 2639-1538 (online), the other parts of the endomembrane system, Irrigation Quantification From Space Exploiting Satellite Soil Moisture Products, Using Linker Design In Metal-Organic Framework Synthesis, Superhydrophobic Nanotip And Nanopore Arrays: A Practical Substrate For Surface-Enhanced Raman Spectroscopy, Adapting The Narrative Of Climate Change And Renewable Energy, Glucose Transporters Protect Cancer Cells From Nutrient Deprivation, Meiosis: Metaphase 2, Anaphase 2, Prophase 2, Using Nanotechnology For Electrosynthesis Of Nitrogen-Based Fertilizer Under Ambient Conditions, Controlling Saprolegnia Infections For A Sustainable Aquaculture, The Role Of Seaweeds For Sustainable Aquaculture Development. 24 Terms. Cytoplasm is the entire contents of the cell; including organelles; (only excluding the nucleus/nucleoid) Cytosol is simply intracellular fluid; not containing organelles or their contents. All Rights Reserved. The smooth and rough endoplasmic reticulum plays an important role in all eukaryotic cells. nucleolus FREE Expert Solution Show answer Problem Details The smooth ER is involved in the synthesis of lipids, including cholesterol and phospholipids, which are used in the production of new cellular membrane. The Golgi body consists of stacks of flattened membrane-enclosed and fluid-filled saccules (cisternae). There are two types: rough and smooth. There are two types of endoplasmic reticulum, rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). Synthesis: Ribosomes that are attached to ER, similar to unattached ribosomes, make proteins. The hollow portion of the ER tubules is called the lumen or cisternal space. The rough ER sends newly made proteins to the Golgi apparatus where they are modified and packaged for delivery to various locations within or outside of the cell. The smooth endoplasmic reticulum differs from the rough endoplasmic reticulum (RER) by its lack of ribosomes. Sign up for our science newsletter! The rough endoplasmic reticulum is especially prominent in cells such as hepatocytes. Earn Transferable Credit & Get your Degree, Get access to this video and our entire Q&A library. answer! Proportion The membrane of a cell is made out of a phospholipid bilayer, with a hydrophilic or polar head that interacts with water favorably, and the other side being a hydrophobic fatty acid tail. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. So, cells specializing in protein synthesis have more … IND bluedoor, LLC 3. Description: The largest organelle in many cells, the endoplasmic reticulum (ER) is a network of interconnected membranous tubes and sacs that serve as locations for protein and lipid synthesis. Smooth ER lacks ribosomes. Rough ER contains attached ribosomes while smooth ER does not. Smooth endoplasmic reticulum is involved in the synthesis of lipids. Synthesis: Ribosomes that are attached to ER, similar to unattached ribosomes, make proteins. There are two types: rough and smooth. Meiosis refers to the process by which a single diploid cell divides into 4 haploid cells, each genetically distinct from […], Sustainable ammonia production is vital for the global population growth due to ammonia’s wide use as a fertilizer in agriculture. The rough endoplasmic reticulum is dubbed “rough” is covered in ribosomes, which gives the organelle a bumpy, rough appearance. The structure of the endoplasmic reticulum is similar to a folded membrane. Sciences, Culinary Arts and Personal Microtubules Separate chromosome. The outer membrane of the rER is studded with ribosomes.This gives a basophilic staining to cytoplasm in H&E stains (due to the RNA content). A) ribosome B) smooth endoplasmic re... A) ribosome B) smooth endoplasmic re... Q. Membrane-bound organelles that contain powerful enzymes found in cells are known as a. plasma membrane, releasing the protein to the outside of the cell. Structure: has no ribosomes therefore it is smooth. Granular ER has ribosomes over the surface, giving it a rough appearance. Unlike the ER, the Golgi shows both structural and functional polarization. Smooth endoplasmic reticulum, meshwork of fine tubular membrane vesicles, part of a continuous membrane organelle in the cytoplasm of eukaryotic cells, that is involved in lipid synthesis. Both plant and animal cells. In what organelle does cellular respiration take place? The smooth endoplasmic reticulum (smooth ER) is a membranous organelle found in most eukaryotic cells. This statement certainly applies to the endoplasmic reticulum an organelle found in eukaryotic cells. While the smooth ER performs many functions, including lipid synthesis and ion storage, the rough ER is mainly responsible for protein synthesis using its associated ribosomes. • It is important in the synthesis and storage of steroids and it stores ions as well • In liver cells the smooth ER produces enzymes that help to detoxify certain compounds • Rough ER are very important in the synthesis and processing and packaging of membranes and secretory proteins Phosphorus pentoxide is a covalent compound that […], Aquaculture has been called upon to become a more relevant source of food for humanity since the stagnation of global […]. These ribosomes make proteins that are … Proteins that will not stay in the endoplasmic reticulum are packed into vesicles and sent to the Golgi apparatus. The smooth endoplasmic reticulum differs from the rough endoplasmic reticulum (RER) by its lack of ribosomes. The Ribosome: Structure, Function and Location, Plasma Membrane of a Cell: Definition, Function & Structure, Plastids: Definition, Structure, Types & Functions, What is a Nucleolus? Services, Endoplasmic Reticulum: Definition & Functions, Working Scholars® Bringing Tuition-Free College to the Community. The endoplasmic reticulum is an organelle that is responsible for the … While, on the other hand, the smooth ER performs the synthesis of lipids and steroids. Want more Science Trends? The rER plays a major role in protein synthesis. Smooth ER is a part of the endomembrane system that form important structural lipids like cholesterol and phospholipids. How does the synthesis of an integral membrane... Why only the rough endoplasmic reticulum needs... What are the advantages provided by the... Why does blockade of sarcoplasmic reticular Ca++... What is an analogy for rough endoplasmic... What is an analogy for endoplasmic reticulum? The endoplasmic reticulum (ER) is a series of interconnected membranous sacs and tubules that collectively modifies proteins and synthesizes lipids. Lipids are also produced in the ER. Some will be secreted from the cell, via an organelle called a vesicle, to carry out functions elsewhere in the animal’s body, while others will remain in the membrane of the endoplasmic reticulum or be moved to other organelles. Rough ER stays closer to the nucleus and coordinates protein synthesis. In a few sentences, what is the function of smooth... What is the organelle of the cell called where a... What proteins are not made at the rough ER? The endoplasmic reticulum is a highly versatile organelle involved in synthesis and transport of proteins, glycoproteins, and lipoproteins; synthesis of cholesterol, steroids, phospholipids, and triglycerides; it participates in degradation of glycogen, and in the metabolism of xenobiotics. The smooth-endoplasmic-reticulum (SER) organelle produces fats and cholesterol, but a lipid-synthesizing cell needs more than just extra SER. Golgi Apparatus: protein modification and sorting, cisternal maturation iv. The main function this organelle is protein and lipid synthesis as well as storage of certain ions and molecules required for energy. Rough endoplasmic reticulum is named for its rough appearance due to ribosomes attached to its folds. Functions of the smooth endoplasmic reticulum : Synthesis, storage, and transport of lipids. Rough-endoplasmic reticulum - rER. Smooth endoplasmic reticulum is where lipid synthesis occurs, and where the organelle handles toxic substances within the cell. The endoplasmic reticulum (ER) is a type of organelle found in eukaryotic cells that forms an interconnected network of flattened, membrane-enclosed sacs or tube-like structures known as cisternae. Here, lipid components are first moved to the ER-Golgi intermediate compartment where they are biochemically modified. Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids? Smooth ER, by contrast, is not associated with ribosomes, and its functions differ. What’s the difference between these two different types of organelle? The rough ER sends newly made proteins to the Golgi apparatus where they are modified and packaged for delivery to various locations within or outside of the cell. The rough endoplasmic reticulum is dubbed “rough” is covered in ribosomes, which gives the organelle a bumpy, rough appearance. Moreover, the smooth ER involves a tube-like structure. Think of a cell as a “multitude of membranes” we said in an earlier section. Endoplasmic reticulum. lysosomesd. Moreover, the smooth ER involves a tube-like structure. … These organelles in rough endoplasmic reticulum form cisternae, a mesh of interconnected, flattened membrane-enclosed sacs and in SER exist as tubular structures. The amount of rough endoplasmic reticulum a cell has depends upon the function of the cell. While the smooth ER performs many functions, including lipid synthesis and ion storage, the rough ER is mainly responsible for protein synthesis using its associated ribosomes. This organelle recycles other old organelles, digesting them so that the molecules that make them up can be used to create new structures. Ribosomes are the structures responsible for making proteins, and after the proteins are created they are sent into the lumen. Draw an E-R Diagram for the following situation. The Endoplasmic Reticulum is attached to the nuclear envelope and extends through the cell. Also, this network increases the area for storage of key enzymes and their products. and tell a little abo… Three … The endoplasmic reticulum is what kicks off the process that will take lipids and proteins to their respective destinations, enabling the body to perform a wide variety of complex actions. Production of DNA is replication and … The rough ER contains ribosomes and hence appears rough whereas the smooth ER does not have ribosomes. Right: A 3D view of rough ER. The smooth ER (endoplasmic reticulum) function involves manufacturing and packaging, including the synthesis of lipids and hormones which are used for the production of new cellular membranes. Mitochondria-Powerhouse of the cell and generates chemical energy needed for the body (ATP). In contrast to the function of the rough ER, the smooth ER is important in the synthesis of membrane lipids or their precursors i.e. There is even a special type of smooth endoplasmic reticulum known as the sarcoplasmic reticulum, which is located in striated muscle cells and helps regulate their calcium ion concentration. Hjortur_Gunnarsson PLUS. The proteins synthesized by the rough ER. Moreover, ER plays a key role in calcium storage, carbohydrate metabolism and lipid synthesis and metabolism. Both the rough endoplasmic reticulum and the smooth endoplasmic reticulum work in conjunction with the other parts of the endomembrane system to carry out the cell’s functions and enable it to maintain homeostasis. However, these two functions are performed in separate areas of the ER: the rough ER and the smooth ER. Given that the smooth ER is involved in the biosynthetic pathways of sterol and steroid, it's commonly found in cells of the adrenal gland where a group of steroid hormones are secreted. In both animal and plant cells Genetic code (DNA), Microfilament Cell shape Microvilli. The rough ER is covered with ribosomes where the information carried in messenger RNA molecules is translated into proteins. While, on the other hand, the smooth ER performs the synthesis of lipids and steroids. It is a subset of the endomembrane system of the endoplasmic reticulum. There are two types of ER on the basis of the absence or presence of ribosomes. © copyright 2003-2020 Study.com. Moreover, ER plays a key role in calcium storage, carbohydrate metabolism and lipid synthesis and metabolism. Become a Study.com member to unlock this In both animal and plant cells. Want to know more? You may also remember that there are two different versions of this organelle. from RNA to protein). The rough ER sends newly made proteins to the Golgi apparatus where they are modified and packaged for delivery to various locations within or outside of the cell. The cell is the basic unit of life. […], As the global human population continues to grow, secure access to nutritious food is most important for a sustainable society […], Lions are one of the most striking animals on earth, being large cats with impressive manes on the males and […], There are 23 countries in North America and 9 dependent territories, with the United States of America being the largest […], Phosphorous pentoxide is the common name for the compound with a chemical formula P4O10. It makes up 50% of the membranes in a eukaryotic cell. The RER is named for the appearance of its outer surface, which is studded with protein-synthesizing ribosomes. The proteins and lipids that were created by the endoplasmic reticulum are frequently modified further by the Golgi body. The process of protein folding means they are modified, an example of which is the fusion of carbohydrate sidechains to the proteins. The smooth endoplasmic reticulum, as you might have guessed, does not have ribosomes. Cytosol. It fills up the entire intracellular space. Ribosomes are the structures responsible for making proteins, and after the proteins are created they are sent into the lumen. We love feedback :-) and want your input on how to make Science Trends even better. Once unloaded of cargo, the vesicles will return to the endoplasmic reticulum and begin the process over again. What is the difference between the rough and smooth endoplasmic reticulum? As mentioned above, rough endoplasmic reticulum is mainly responsible for synthesis of proteins and smooth type is involved in synthesis and metabolism of lipids. Hepatocytes, where it participates in the synthesis of lipoprotein molecules. Endoplasmic reticulum- cell Organelle 1. LEARNING OBJECTIVES FOR THIS SECTION. Rough ER-To produce proteins Smooth ER-To synthesize lipids, phospholipids in plasma membrane, and steroids. Organelles (nucleus, ribosome, Golgi apparatus, mitochondria, vesicles, centriole, lysosomes, smooth ER, rough ER, cytoskeleton, peroxisomes, plasma membrane) All other trademarks and copyrights are the property of their respective owners. Its main functions are the synthesis of lipids, steroid hormones, the detoxification of harmful metabolic byproducts and the storage and metabolism of calcium ions … Ribosomes. This is where most protein synthesis occurs. LEARNING OBJECTIVES FOR THIS SECTION The endoplasmic reticulum works to synthesize and modify lipids and proteins, and it is made up of a series of sacs and tubules. Smooth ER: lipid synthesis, calcium ion storage, poison detoxification ii. Granular ER has ribosomes … While the smooth ER performs many functions, including lipid synthesis and ion storage, the rough ER is mainly responsible for protein synthesis using its associated ribosomes. Some of the lipids include the phospholipids which are used to create new sections of cell membrane and cholesterol which are also used in cell membranes and for the creation of other substances like hormones and vitamin D. Steroid hormones are the hormones created by the steroid glands, and include substances like adrenal steroids and sex hormones. The dark spots are ribosomes. In the great majority of cells, smooth ER regions are scarce and are often partly smooth and partly rough. The smooth endoplasmic reticulum is a continuous section of the rough endoplasmic reticulum, it just has no or few ribosomes. mitochondriae. Smooth ER acts as the storage organelle. Free/ Bound Ribosomes. They are sometimes called transitional ER because they contain ER exit sites from which transport vesicles carrying newly synthesized proteins and lipids bud off for transport to the Golgi apparatus. This process is known as phagocytosis. Unlike protein synthesis, which mostly occurs in the rough ER, lipid synthesis takes place in the smooth ER which contains enzymes involved in the biosynthetic pathways. b. Organelles i. a lipid is in fact not an organelle it is one of of the four molecules of life and is made by the smooth endoplasmic reticulum ,ER The smooth ER is like a network of interconnected tubules. In certain cell types, smooth ER plays an important role in the synthesis of steroid hormones from cholesterol. Ribosomes are concerned with protein synthesis. While the smooth ER performs many functions, including lipid synthesis and ion storage, the rough ER is mainly responsible for protein synthesis using its associated ribosomes. They are rough or granular ER and smooth or agranular ER. Rough ER also manufactures membranes. Lipids are also produced in the ER. has ribosomes embedded into the membrane giving it the rough l… Endoplasmic Reticulum. The lumen is the hollow space within the tubules and sacks of the endoplasmic reticulum. Endoplasmic reticulum is an organelle located in the cytoplasm of eukaryotic cells and consists of a network-like membrane. Functions. Unlike protein synthesis, which mostly occurs in the rough ER, lipid synthesis takes place in the smooth ER which contains enzymes involved in the biosynthetic pathways. The smooth endoplasmic reticulum is especially abundant in mammalian liver and gonad cells. In order to answer this question, let’s go over what the role of the endoplasmic reticulum is. The lumen is the hollow space within the tubules and sacks of the endoplasmic reticulum. [In this figure] The anatomy of ER. Rough ER: Protein synthesis iii. Nuclear membrane Nucleoplasm Nucleolus. On the cytoplasmic side of its membrane, almost all the lipid constituents of the membranes are synthesized: cholesterol, phospholipids, glycolipids, etc. The function of the smooth endoplasmic reticulum differs somewhat depending on what type of cell it is in. The proteins synthesized by the rough ER. Rough endoplasmic reticulum. Functions • The smooth ER-Carbohydrate and lipid synthesis • Smooth ER acts as a storage organelle. Rough ER and Smooth ER. Water is … Rough endoplasmic reticulum (ER) is involved in the synthesis of proteins. Smooth endoplasmic reticulum, meshwork of fine tubular membrane vesicles, part of a continuous membrane organelle in the cytoplasm of eukaryotic cells, that is involved in lipid synthesis. Structure: has no ribosomes therefore it is smooth. how is ER formed? The modified proteins are then sent to a variety of destinations. While the smooth ER performs many functions, including lipid synthesis and ion storage, the rough ER is mainly responsible for protein synthesis using its associated ribosomes. There are two types of ER on the basis of the absence or presence of ribosomes. Hepatocytes, where it participates in the synthesis of lipoprotein molecules. Function: lipid and carbohydrate synthesis. Smooth ER is also a location for storage and transport. Endoplasmic means “within the plasm” and reticulum mean“network” The endoplasmic reticulum (ER) is a network of flat and vesicular structures which extends throughout the cytoplasm in plant and animal cells. In liver cells, the smooth endoplasmic reticulum helps detoxify toxic chemicals and compounds.