11/6/2012 Bio Lab W 8
Cell Structure and Function
Prokaryotic cells do not contain a nucleus. Eukaryotic cells do contain a nucleus. Organisms are eukaryotic except Bacteria and Achaea. Organelles are small membranous bodies, each with a specific structure and function. Prokaryotes do have cytoplasm, which is the material bounded by a plasma membrane and cell wall. This contains ribosomes, small granules that coordinate the synthesis of proteins. Prokaryotes also have a nucleoid which is the inner interior of the cell where the DNA is organized and stored but not enclosed by the membrane.
Prokaryotic cells lack membrane-bounded organelles as well as a nucleus. Their DNA is in a nucleoid region. The prokaryotic cell consists of a fimbriae, flagellum, ribosome, nucleoid, plasma membrane, cell wall, and capsule. The fimbriae is hair-like bristles that allow adhesion to the surfaces. The flagellum is rotating filament present in some bacteria that pushes the cell forward. Ribosomes are the site of protein synthesis. The nucleoid is the location of the bacterial chromosome. The plasma membrane is the main entrance and exit of molecules thru the cell. The cell wall covers, protects, supports and shapes the cell. The capsule has a gel-like coating outside cell wall.
The animal cell and plant cell structures are structurally different. There are many organelles are membranous, such as the nucleolus, endoplasmic reticulum, Golgi apparatus, vacuoles and vesicles, lysosomes, peroxisome, mitochondrion, and chloroplast. The unique structures between the two: plant cells- large central vacuole, cell wall, chloroplast; animal cell- small vacuoles, and centrioles.
In the animal cell, they have many structures and functions: plasma membrane defines the cell boundaries and regulates molecule passage in and out the membrane. The nucleus stores genetic information such as DNA. The nucleolus is the ribosomal subunit...