Bacteria
Bacteria grow in different shapes, round shaped bacteria are called cocci, rod shaped bacteria are called bacillus. Usually grow in colonies, if the colonies grow in straight lines we call it a Strept colony while if they are arranged in rings they are called staph. Some cocci grow in pairs these are called diplococcus.
Cell wall is made from peptidoglycan.
Bacteria replicates asexually, the first thing that the bacterium would do is it would replicate it’s nucleoid, then the cell membrane grows in the middle of the cell to separate the cell in two with one nucleoid on each side, then the cell wall also starts growing in this mid-section, after some time the cells will split. The time this process takes is called the generation time.
Endospore formation: This is similar to binary fission. The cytoplasm of the bacterium shrinks, into one side of the bacterium with the nucleoid inside it. The cell wall encircles close to the cell membrane making a spore with a very thick cell wall.
If the cell wall is thick you get the multiple peptidoglycan layers stuck with pins of proteins, these pins keep the peptidoglycan layers in place. bellow you would have the cell membrane which is semi-permeable. This is a typical gram positive bacteria cell wall.
In a gram negative bacteria one would find a cell membrane on the outside, then one layer of peptidoglycan sandwiched between another cell membrane which is on the inside of the bacterium.
Population curve for bacterial growth
Endospore formation: This is similar to binary fission. The cytoplasm of the bacterium shrinks, into one side of the bacterium with the nucleoid inside it. The cell wall encircles close to the cell membrane making a spore with a very thick cell wall.
If the cell wall is thick you get the multiple peptidoglycan layers stuck with pins of proteins, these pins keep the peptidoglycan layers in place. bellow you would have the cell membrane which is semi-permeable. This is a typical gram positive bacteria cell wall.
In a gram negative bacteria one would find a cell membrane on the outside, then one layer of peptidoglycan sandwiched between another cell membrane which is on the inside of the bacterium.
Population curve for bacterial growth