ORGANELLE STRUCTURE FUNCTIONMitochondriadouble membrane, outer smoothpowerhouse of the cell, site of
inner-cristae folded to increase SAcellular respiration, produces
Lysosomespherical body in cytoplasmsuicide sac contains
digestive enzymes that merge
Microtubuleslong protein tubescellular framework
cilia + flagellalong protein structures, 9+2movement of cell
arrangement of microtubules
Rough Endoplasmic Reticulum The rough endoplasmic reticulum manufactures membranes and secretory proteins. In leukocytes the rough ER produces antibodies. In pancreatic cells the rough ER produces insulin. The rough and smooth ER are usually interconnected and the proteins and membranes made by the rough ER move into the smooth ER to be transferred to other locations. Smooth Endoplasmic Reticulum The smooth ER has a wide range of functions including carbohydrate and lipid synthesis. It serves as a transitional area for vesicles that transport ER products to various destinations. In liver cells the smooth ER produces enzymes that help to detoxify certain compounds. Inmuscles the smooth ER assists in the contraction of muscle cells, and in brain cells it synthesizes male and female hormones.
The Golgi complex is composed of numerous sets of smooth cisternae, which are coated with lipid membranes. Each disc-shaped cisternae forms a structure that resembles a stack of plates, called a Golgi stack. The Golgi complex contains a great number of vesicles. These vesicles are used to send molecules to the cellular membrane, where they are excreted. There are also larger secretory vesicles, which are used for selective excretion.
The Golgi is principally responsible for directing molecular traffic in the cell - nearly all molecules pass through the Golgi complex at some point in their existence. The sorting is mediated by the vesicles. When proteins bind with their appropriate receptor on the vesicle, they are encoated in the vesicle and transported away.
The nucleus is the largest organelle in a cell. The nucleus directs all activity in the cell. It also controls the growth and reproduction of the cell. The nucleus could be compared to a manager of a company, they both control activity in there facility. The nucleus is surrounded by a nuclear membrane that protects it from other parts of the cell. It also contains a nucleolus, which is a secondary organelle.
It also contains the blueprints of the cell in the chromatin inside the nucleus. The chromatin is like long strands in the nucleus that carry DNA and proteins.
Cytoplasm - Filling Fluid
Cytoplasm is the fluid that fills a cell. Scientists used to call the fluid protoplasm. Early on, they didn’t know about the many different types of fluids in the cell. There is special fluid in the mitochondria, endoplasmic reticulum, Golgi apparatus, and nucleus. The only two ‘plasms’ left are cytoplasm (the fluid in the cell also called cytosol) andnucleoplasm (the fluid in the nucleus). Each of those fluids has a very different composition.
The cell organelles are suspended in the cytosol. You will learn that the microfilamentsand microtubules set up a “skeleton” of the cell and the cytosol fills the spaces. The cytoplasm has many different molecules dissolved in solution. You’ll find enzymes, fatty acids, sugars, and amino acids that are used to keep the cell working. Waste products are also dissolved before they are taken in by vacuoles or sent out of the cell.