Learning About Cell Biology

What is Cell Biology
Cellular Components
The Endomembrane System
Golgi Apparatus
Vesicles and Cellular Transport
The Mitochondria
The Plasma Membrane

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Cell Transport

Proteins and other structures are transported through the cytoplasm via vesicles attached to cytoskeleton structures. The cytoskeleton is a complex structure made up of microtubules, microfilaments, and intermediate filaments. A vesicle is a small membrane-enclosed sac inside the cell that stores or transports substances within a cell.

Vesicles form naturally by taking part of another membrane, such as the plasma membrane or the Golgi complex, and surrounding the "cargo" it was intended to carry.

Most vesicles have specialized functions which depends on the contents, some are made to secrete these proteins or enzymes outside the cell, in which case they take part in exocytosis.

Others are meant to bring substances inside the cell, through the plasma membrane, and participate in endocytosis.

It is difficult to tell the difference between different types of vesicles without sampling their contents becasue they tend to look very much alike.

The vesicle is separated from the cytosol by at least one phospholipid bilayer.

Vesicles store, transport, or digest cellular products and waste. The membrane enclosing the vesicle is similar to that of the plasma membrane, and vesicles can fuse with the plasma membrane to release their contents outside of the cell. Vesicles can also fuse with other organelles within the cell. Because it is separated from the cytosol, the inside of the vesicle can be made to be different from the cytosolic environment. For this reason, vesicles are a basic tool used by the cell for organizing cellular substances.

The vesicle is formed via blebbing off of either the plasma membrane, the Golgi, or endoplasmic reticulum. This is called

Microtubules are hollow cylinders whcih radiate from the centrosome. These microtubules function as compression-resistant girders of the cytoskeleton. These structures are found in the cytoplasm of all eukaryotic cells and function as support and mobility systems.

The centrosome is a region near the nucleus that includes two centrioles. A identifying feature of the centrioles are the nine set of triplet microtubules arranges in a ring formation.

The Simple Store

All Simple Schooling unit study courses as well as the Simple Days, will be on sale in the Store. We are hoping to add two new courses every month in 2009.

Courses scheduled for February release are:

Forensic Science Available February 15th(Upper grades)

Human Anatomy I Available March 30 (upper grades)