On
26th September 2014, I learnt about internal structures of
PROKARYOTES! I already learn about it when I was in matriculation.
But, hm, I think I've forgot all things. First of all, prokaryotes
can be divided into two domains which is bacteria and archaea.
Prokaryotes can be defined as a group of organisms which have lack of
nucleus and membrane-bound organelle. Most of the prokaryotes are
unicellular. The basic shape that prokaryotes have are coccus,
bacillus and spiral. There are also additional shapes such as
star-shape, square and triangular. The shape of this prokaryotes are
influenced by the environmental conditions, age of culture and
antibiotic pretreatment. I think bacteria with star-shape is just too
cute! :) The smallest prokartoes goes tooooooooooooo.. Mycoplasma!
The range of smallest prokaryote is 0.3um and below. Next, there are
also extrernal structures to the cell wall of the prokaryotes. For
example :
- Glycocalyx - protection
- Flagella - motility
- Axial filaments - present in spirochetes group of bacteria
- Fimbrae (attachment) and Pili (reproduction)
For the cell wall, it can be divided into two types which is gram +ve and gram -ve. Gram +ve consists of thick peptidoglycan and no lipopolysaccharides while gram-ve consists of thin peptidoglycan and has lipopolysaccharide as the outer layer. In terms of structures of the cell wall, bacteria has beta-1,4 glycosidic bonds whereas archaea has beta-1,3 glycosidic bonds. I just know that archaea and bacteria have different type of glycosidic bonds ~
Additional information : Lysozyme which is can be found in tears, saliva and sweat can break the bonds of the cell wall! So it can kill the bacteria.
** We also make our own mind map on the whiteboard regarding this topic! A little bit messy but never mind because we love it ♥
