Antony van Leeuwenhoek, a Dutch shopkeeper who had great skill in crafting lens, used microscopes that were far more complex than the ones we use today.
In the 1670s, van Leeuwenhoek discovered organisms.
Other scientists were able to see different parts of cells.
These are the principles that are still standing today.
You will be able to name examples of prokaryotic and eukaryotic organisms by the end of this section.
All cells have the same four components: 1) a plasma membrane, an outer covering that separates the cell's interior from its surrounding environment; 2) a cytoplasm, a region within the cell in which other cellular components are found; and 3) DNA, the genetic material of the cell.
Prokaryotes and cells differ in several ways.
This is different in the eukaryotes.
The structure of a prokaryotic cell is shown in this figure.
Unlike Archaea and Eukaryotes,bacteria have a cell wall made of peptidoglycan, comprised of sugars and amino acids, and many have a polysaccharide capsule.
The cell wall helps the cell maintain its shape and prevents dehydration.
The cell can attach to surfaces in its environment with the help of the capsule.
flagella, pili, and fimbriae are some of the prokaryotes that have flagella.
Most pili are used to exchange genetic material during a type of reproduction called conjugate.
The relationship between form and function can be seen at all levels in nature, and this will become clear as we explore eukaryotic cells.
The principle "form follows function" can be found in many contexts.
Birds and fish have streamlined bodies that allow them to move quickly through air or water.
One can deduce the function of a structure by looking at its form, because the two are matched.
The word "euthanasia" refers to the presence of the nucleus in these cells.
Just as the organs of your body have specialized functions, so too do the organelles, which are little organs.
The small size of prokaryotes allows ion and organic molecule that enter them to quickly spread to other parts of the cell.
Any waste produced within a prokaryotic cell can be quickly moved out.
Different structural adaptations have been made by larger cells to enhance cellular transport.
The large size of these cells would not be possible without these adaptations.
Cell size is limited because volume increases more quickly than surface area.
The relative size of the surface area across which materials must be transported decreases as a cell becomes larger.
The figure shows the relative sizes of different types of cells.