PROKARYOTIC CELLS by Noor Ashikin bt Lamat
by Noor Ashikin
1. live in a wide variety of environment and can be found in water, soil, and the air.
1.1. generally exist as unicellular organism
1.1.1. among the first organismisms on the earth
1.1.2. extreme thermophiles - live in incredible hot environment
2. Cell Wall
2.1. Two types which is Gram Negative Cell Wall and Gram Positive Cell Wall
2.2. Responsible for shape of the cell and prevent bacterial cells from rupturing due to changes in pressure.
3. Lack of :
3.1. Membrane-bound nucleus
3.2. Cytoskeleton
3.3. Membrane-bound organelles
3.4. Internal membranous structure
3.4.1. Golgi Apparatus
3.4.2. Endoplasmic Reticulum
4. Common Structures and Their Functions
4.1. Nucleoid : contain genetic material
4.2. Ribosomes : protein synthesis
4.3. Plasma Membrane : mechanical boundary of cell, nutrient and waste transport.
4.4. Gas Vacoule : buoyancy for floating in aquatic environments
4.5. Semifluid medium inside of a cell is the cytoplasm : composed of water, salts, and dissolved organic molecules
5. Special Component of Cell Wall
5.1. External Structures.
5.1.1. Fimbriae and Pili
5.1.1.1. small bristlelike fibers that allow bacteria to attach themselves to surface
5.1.2. Flagella
5.1.2.1. use to help bacteria move in water
5.1.3. Sex pili
5.1.3.1. used to transfer DNA from one bacteria to another
5.2. Internal Structures
5.2.1. Plasma (cytoplasmic) Membrane
5.2.2. Cytoplasm
5.2.3. Nuclear Area
5.2.4. Ribosomes
6. are simpler and much smaller in size(than eukaryotic cells)
7. Archaeans
7.1. live in extreme habitats
7.1.1. can be found in extreme environment such as hot spring water and deep seawater vent.
7.2. may be the oldest life forms on earth.
7.3. this group include many extremophiles
7.3.1. extreme halophiles - live in extremely salty environments