Cell structure - pmt

• All living organisms are made of cells, there are several different types of cells, some of them sharing some common features.
• Human are made up of eukarvotic cells.
• All eukarvotic cells contain a nucleus and membrane bound organelles.
• A more detailed structure of cells called the ultrastructure can be obtained by using a microscope.
• Ultrastructure of eukaryotic cells includes Chromatin, Nucleolus, Nuclear envelope, Nucleus, Plasma membrane, Endoplasmic reticulum, Cytosol, Lysosome, Mitochondrion, Centrioles, Centrosome, matrix, Rough endoplasmic reticulum, Ribosomes, Golgi apparatus, Secretion being released from cell by exocytosis, Microvilli, Microfilament, Microtubule, Intermediate filament, Peroxisome, Nucleus is surrounded by a double membrane called the envelope containing pores which enable molecules to enter and leave the nucleus, The nucleus also contains chromatin and a nucleolus which is the site of ribosome p
• Golgi apparatus is a series of fluid filled, flattened & curved sacs with vesicles surrounding the edges, Golgi apparatus processes and packages proteins and lipids, it also produces lysosomes.
• Mitochondria are usually oval shaped, bound by a double membrane called the envelope, The inner membrane is folded to form projections called cristae with matrix on the inside containing all the enzymes needed for respiration.
• Centrioles are hollow cylinders containing a ring of microtubules arranged at right angles to each other, Centrioles are involved in cell division.
• Proteins are produced on the ribosomes, Proteins which are produced on the surface on RER are folded and processed in the, The proteins are then transported from the RER to the Golgi apparatus in vesicles, They are then modified in the Golgi apparatus, Golgi apparatus packages proteins into vesicles to be transported around the cells o where they're required, Some of the proteins such as extracellular enzymes leave the cell by exocytosis.
• Cell wall is a rigid outer covering made of peptidoglycan, Capsule is a protective slimy layer which helps the cell to retain moisture and adhere to surfaces, Plasmid is a circular piece of DNA, Flagellum is a tail like structure which rotates to move the cell, Pili are hair-like structures which attach to other bacterial cells, Ribosomes are the site of protein production, ribosomes are composed of two sub units and are the site of protein production, Lysosome is a vesicle containing digestive enzymes bound by a single membrane, The cytoskeleton of the cell plays an important role in providi