Organelles Flashcards
(20 cards)
Describe the plasma membrane
A fluid mosaic lipid bilayer (phospholipids, cholesterol, glycolipids) that is studded with proteins. It surrounds the cytoplasm
What is the function of the plasma membrane
Protects cellular contents, makes contact with other cells, contains cell identification markers and determines what goes into and out of the cells
Describe the cytoplasm
Cellular contents between the plasma membrane and the nucleus both cytosol and organelles
What is the function of the cytoplasm
It is the site of all intracellular activities outside of the nucleus
Describe the cytosol
It is composed of water, solutes, suspended particles, lipid droplets, and glycogen granules
What is the function of the cytosol
It is the fluid in which many of the cells reactions occur
Describe the cytoskeleton
A network in the cytoplasm that is composed of three protein filaments. Microfilaments
Intermediate filaments
Microtubules
What is the function of the cytoskeleton
Maintains shape and general organization of cellular contents. It is also responsible for cell movements
Describe centrosomes
A pair of centrioles and a pericentriolar matrix
What is the function of centrosomes
The pericentriolar matrix contains tubulins which are used for growth of the mitosis spindle and microtubule formation
Describe cilia and flagellum
Motile cell surface projections that contain 20 micro tubules and a basal body
Describe the function of cilia and flagella
Cilia: move fluids over the cells surface
Flagella: move the entire cell
Describe the structure of ribosomes
Composed of two subunits of ribosomal RNA and proteins. They may be attach to rough ER or free in the cytosol
What is the function of ribosomes
Protein synthesis
Describe endoplasmic reticulum
A membranous network of flattened sacs or tubules it is covered by ribosomes. Smooth ER lacks ribosomes
What is the function of Rough ER
Synthesizes glycoproteins and phospholipids that are transferred to cellular organelles, inserted into the plasma membrane, or secreted during exocytosis
What is the function of smooth ER
Synthesizes fatty acids and steroids, inactivates or detoxifies drugs, removes phosphate group from glucose-6-phosphate and stores and releases calcium ions in muscle cells
Describe the structure of the Golgi apparatus
It’s made of 3-20 flattened membranous sacs called saccules. It is functionally divided into entry face medial saccules and exit face
Describe the function of the Golgi
Entry face accepts proteins from rough ER, medial saccules form glycoproteins, glycolipids, and lipoproteins, Exit face modifies molecules further then sorts and packages them for transport
Describe the lysosome
A vesicle formed from the golgi complex that contains digestive enzymes
