The Prokaryotic Cell. Detailed Biology Summary on the Prokaryotic Cell.
THE PROKARYOTIC CELL
Science is not your favorite subject and you need some clarifications on certain topics? Don’t worry, we are here to help you and in this note we will focus on the prokaryotic cell , a type of cell that lacks the nucleus and other structures typical of eukaryotic organisms. Here is the summary and the clear and concise explanation on the prokaryotic cell .
All living things, with the exception of viruses , are made up of cells, small membrane-bound structures filled with chemicals in aqueous solution that interact to give rise to their basic properties. These properties include, among others, the acquisition and use of energy, the ability to reproduce, to respond to the environment, to carry out a variety of controlled chemical reactions, and to maintain a relatively constant internal environment despite changes in the external environment.
THE PROKARYOTIC CELL AND THE EUKARYOTIC CELL
In the living world there are two types of cells that are distinguished by the type of internal structures they contain: prokaryotic cells and eukaryotic cells . Although both contain the same types of molecules, there are fundamental differences between them. The eukaryotic cell is generally much larger than the prokaryotic one and much more complex in terms of structure and function. The peculiar characteristic of the eukaryotic cell is the presence of a true nucleus delimited by a membrane, which houses the genetic material. In addition, eukaryotic cells contain various organelles.
THE PROKARYOTIC CELL: STRUCTURE
The simplest is the prokaryotic cell . Prokaryotic cells include organisms belonging to two of the three kingdoms – Bacteria and Archaea (the third is the Eukarya).
Prokaryotic cells have a cell wall made of peptidoglycan, a substance unique to prokaryotes. Beneath the cell wall is a plasma membrane that encloses a cytoplasm containing DNA, RNA, proteins, and various other small molecules. The cytoplasm has no distinct internal organization, although the DNA is isolated in a loosely bounded region of the cytoplasm called the nucleoid. The nucleoid is not surrounded by a membrane, nor are there any membrane-bound cytoplasmic organelles in prokaryotes. In prokaryotes, the chromosome is composed of a double-stranded DNA molecule packaged in the nucleoid for interaction with RNA and proteins, which then maintain the DNA structure in a highly supercoiled form.
