These also protect bacterial cells from attack by other microbes or the host anti-inflammatory system like antibodies, and even from antibiotics. They also prevent the prokaryotic cell from drying up. It has been seen that some capsules act as carbohydrate stores for later requirement. Some bacteria produce slime materials to adhere and float themselves. Bacteria may attach to surface, produce slime, divide and produce microcolonies within the slime layer, and construct a biofilm, which becomes an enriched and protected environment for themselves and other bacteria.
This is the most important structure of the prokaryote cell. It allows a permeative barrier which is responsible for selecting the type of material to enter the cell. Water is freely permeable but other substances need transport process. The phospholipids are amphoteric molecules with a polar hydrophilic glycerol head attached via an ester bond to two nonpolar hydrophobic fatty acid tails, which naturally form a bilayer in aqueous environments.
The cell membrane has a number of functions related to respiration, and ATP synthesis. the plasma membrane is the site of oxidative phosphorylation and photophosphorylation in procaryotes, analogous to the functions of mitochondria and chloroplasts in eukaryotic cells. Membranes also contain enzymes involved in many metabolic processes such as cell wall synthesis, septum formation, membrane synthesis, DNA replication, CO2 fixation and ammonia oxidation
Eukaryotic cells are generally much larger than prokaryotes. They have a variety of internal membranes and structures, called organelles, and a cytoskeleton composed of microtubules, microfilaments and intermediate filaments, which play an important role in defining the cells organization and shape.
The endoplasmic reticulum or ER is a maze of parallel membranous tubules and flattened sacs surrounding the nucleus that connects with the nuclear membrane and runs throughout the cytoplasm.
ER with ribosomes attached is called rough endoplasmic reticulum and is involved in protein synthesis, production of new membrane, modification of newly formed proteins, and transport of these proteins and membrane to other locations within the cell. and is involved in protein synthesis, production of new membrane, modification of newly formed proteins, and transport of these proteins and membrane to other locations within the cell. and contains enzymes for lipid biosynthesis, especially the synthesis of phospholipids and steroids. The smooth endoplasmic reticulum forms transition vesicles to transfer molecules produced in the rough ER to the Golgi complex.
This structure is not present in the prokaryote cell. The nucleus in eukaryotic cells is separated from the cytoplasm by a nuclear envelope (nuclear membrane). The nucleus divides by mitosis. Inside the nucleus is a fluid called nucleoplasm, a nucleolus and linear chromosomes composed of negatively charged DNA associated with positively charged basic proteins called histones to form structures known as nucleosomes. When the cell is not replicating, the DNA and proteins appear as a threadlike mass called chromatin. During mitosis the chromatin coils into thick rodlike bodies called chromosomes