Cells are the basic building block of life. Cells can be either Eukaryotic or Prokaryotic cells. Organism can only contain either one but not both of them. Prokaryotic cells are usually much smaller than Eukaryotic and are less complex. Bacteria are made up of one or more prokaryotic cells. Bacteria are made up of one or more prokaryotic cells. While Eukaryotic cell are found inside plant and animal life. Eukaryotic are more advanced and larger. Prokaryotic cell were the first to live on earth they appeared around 3.5 billion year ago and the Eukaryotic appear around 2.1 billion year after (Campbell Essential Biology, 2012).
The eukaryotic structure consists of the following organelle which includes mitochondria, chloroplast, the endoplasmic reticulum, the Golgi apparatus, lysosomes and nucleus. These organelles perform a specific function that help the cell survive. The organelles are separated from the rest of the cellular space by a membrane; it is like having a separated room in a home. The nucleus is the most critical part of the eukaryotic cell. The nucleus house most of the eukaryotic cell’s DNA and is surrounded by a double membrane. A prokaryotic cell lack a nucleus it DNA is coiled into a nucleus-like region called the nucleoid, which is not partitioned from the rest of the cell by membrane (, Campbell Essential Biology 2012).
The two organelles that work as a cellular power station are chloroplast and mitochondria. The chloroplast which are unique to the photosynthetic cells of plant and algae, are the organelles that perform photosynthesis. The chloroplast consist of three major parts the internal membrane which surround the chloroplast, the stroma is a thick fluid within the chloroplast, the grana is a solar power that trap light energy and convert it into energy. The mitochondria are the organelle of cellular respiration in all that harvest energy from sugar and other food molecule and it produce a form of chemical energy called ATP. The cell use molecules of ATP as a direct energy source that does most of the work. In the human body you can found mitochondria. The cytoskeleton is a network of fiber extending throughout the cytoplasm. The cytoskeleton serves as both skeleton and muscles for the cell. The cytoskeleton helps support the cell and maintain it shape. The lysosome is a membrane-enclosed sac of digestive enzymes found in animal. Lysosome is not present in most plant cells. Lysosome fuse with the food vacuoles, and exposed the food to enzyme that digest it. (Campbell Essential Biology, 2012). The lysosome uses amino acid to nourish the cell and they also help destroy harmful bacteria (Campbell Essential Bilogy, 2012). The vacuoles are large sac of membrane that buds from the Er, Golgi apparatus or plasma membrane.
The vacuoles stores organic nutrient and help maintain homeostatic. The endoplasmic reticulum is one of the main manufacturing facilite within a cell and it main function is to make more membrane. The salivary gland in your mouth is rich in ER (Campbell Essential Biology, 2012). The Golgi apparatus receives, refines, stores, and distributes chemical product of the cell Campbell Essential Biology,2012) . There are many organelles that appear in both eukaryotic and prokaryotic cells. The flagella are variously involved in movement, feeding and sensation. The thylakoid membranes are organized with other molecules into photosynthesis. The ribosomes are located outside of the nucleus and make protein. The nucleon function is to maintenance DNA and transcriptions to reproduce are copy. The plasmid gene carrying circular DNA structure that are not involved in reproduction. Pili are hair like structure on the surface of the cell that attach to other bacterial cell. Shorter pili called fimbriae help bacteria attach to surface (Campbell Essential Biology, 2012). Capsule are found in some bacterial cell, this additional outer covering protect the cell when it is engulfed by other organism, assisting in retaining moisture and help the cell adhere to surface and nutrient. Cytoplasm is a gel like substance composed mainly of water that also contains enzymes salt cell components and various organic molecules. Cell wall outer covering of most of that protects the bacterial cell and give it shape.
Membrane have many different function within a typical cell, such as keeping unwanted viruses out, but probably the most valuable is the portioning of the cell into functional and segregated compartment. Because of the incredible number and often conflicting biochemical reaction occurring in a cell at any one time, the cell must retain order via structural organization or risk chemical chaos. The internal membranes compartmentalize reaction to prevent interference. The cell membrane also separates life from the nonlife on it exterior. In so doing an intact and healthy membrane is selectively permeable because it allows substance needed for cell prosperity to enter and attempt to prohibit the penetration of unwanted and unfriendly substance in the human body (www.infoplease.com).
Retrieved from: www.infoplease.com membrane structure function Simon, Eric J., Dickey, Jean L., Reece, Jane B. (10/2012). Campbell Essential Biology with Physiology, 4/e for EDMC  (Vital Source Bookshelf), Retrieved from http://digitalbookshelf.southuniversity.edu/books