Unit 5 - P1,P2,P3

The rough endoplasmic reticulum is an organelle that plays a large role in synthesising and proteins. This is an important process called protein synthesis. (Plant Cell Anatomy, n.d.)

▪ Know the functions of the various organelles, e.g., glyoxysomes, peroxisomes, ribosomes, chloroplasts, mitochondria, rough and smooth ER, Golgi, etc.

They are very important in the synthesis and packaging of proteins. Some of those proteins might be used in the cell and some are sent out. The ribosomes are attached to the membrane of the ER. As the ribosomes builds the amino acid chain, the chain is pushed into the ER. When the protein is complete, the rough ER pinches off a vesicle. That vesicle, a small membrane bubble, can move to the cell membrane or the Golgi apparatus

Endoplasmic reticulum (ER) – Endoplasmic reticulum is a branching network that fills the cell interior. There two types of ER: Smooth endoplasmic reticulum (SER) – Synthesis of lipid, glycogen and steroids (e.g. cholesterol and testosterone).

The body has two faces, the cis face which fuses with incoming transport vesicles, and the trans face which excretes the secretory vesicles. The cis face fuses with vesicles coming from the ER effectively from many directions due to its convex shape, whereas the concave trans face can direct the secretory vesicles to their destination. When fusing with the cis face, the transport vesicles release their proteins to be absorbed for modification. Each cisternal layer of the Golgi body holds different enzymes which each modify the passing proteins in separate ways. Between the layers the proteins are moved through the gaps by small vesicles. When a protein has been modified correctly, it leaves the Golgi body via secretory vesicles which then carry the modified proteins to the cell membrane or another organelle. The proteins that are transported to the cell membrane are either excreted from the cell, or absorbed into the membrane to aid with its function. Some of the secretory vesicles which hold hydrolytic enzymes stay within the cytoplasm and function as lysosomes.

Exocytosis is the process of how hormones, digestive enzymes and lipids are released from the cell. Vesicles containing the product pinch off from the sacs of the golgi apparatus and move towards the plasma membrane. The vesicles then fuse with the plasma membrane and release the product outside the cell. (CGP, 2009) The cell membrane surrounds all living cells, and is the cell’s most important organelle. It controls how substances can move in and out of the cell and allows cell

The smooth Endoplasmic Reticulum makes lipids and steroids like cholesterol. ------ This is key! (Nnpdf.org, 2016)

serve as the site of lipid synthesis in the cell. The ER functions as the

The main function of the Endoplasmic Reticulum is to produce, store and transport proteins and lipid to most of the cell organelles. The Endoplasmic Reticulum is a large organelle that looks like sheets of folded membranes.

A third structure contained in all three types of cells is the ribosome. Ribosomes are spherical in shape and are made up of RNA and protein. They are often found on the endoplasmic reticulum. Ribosomes are important in the manufacturing of proteins and are the site at

C. Membrane-bound ribosomes, is incorrect. Ribosomes are made of two different subunits that each have a significant purpose within the cell and each aid in building proteins. If mRNA encodes with a protein used for secretory processes, the ribosome then gets attached to the rough endoplasmic

The smooth ER does not have any ribosomes on it's membrane. It's functions can vary depending on the differences of the cell it is located in. The smooth ER makes lipids, breaks down carbohydrates, and detoxifies substances that may be harmful to the cell.

Endomembrane System- is a system of membrane based organelles within the eukaryotic cell that are either in direct contact with each other or communicate through the use of vesicles. A primary role this system plays in intracellular processes is treatment and transport of proteins. The membranes and organelles include the nuclear envelope, the endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and peroxisomes.

Many cells are filled with a complex network of tube like things known as the endoplasmic reticulum. The endoplasmic

The two largest compartment that can be found in the eukaryotic cells are the inner region of the endoplasmic reticulum is the cisternal space and outside of it is called the cytosol which dissolved organic molecules such as proteins and ions. There are two different types of ER: rough ER and smooth ER. Rough ER cannot be seen through light microscopes. The proteins that being made are exported from the cell, sent to lysosomes or vacuoles or placed in the plasma membrane. In this ER the proteins can be changed into glycoproteins and it is made to separate itself from other products and package it into vesicles that moves to the golgi for transportation. Smooth ER is used to store intracellular Ca2+. Also, it is responsible for the modification of random substances to purify it from being poisonous, in other words it is used for