Bacterial Chloroplasts And Cytomembrane Lamellae

Bacterial Chloroplasts and Cytomembrane Lamellae: Innovative Structures in Photosynthetic Microbes Name : Minggu Menang Class : 19-A Microbial cell structures can be divided into prokaryotic and eukaritic cells. Eukaryotic cell types are cell types whose development has been perfect, have a true cell nucleus in which there are chromosomes containing hereditary components (DNA), have a wall / core membrane. Eukaryotic cell types are found in higher level bodies (plants and animals) and some living bodies classified as Protista: Fungi including yeast, Protozoa, and Algae. While the Prokaryotic cell type is a simple cell type, does not have a true nucleus, its hereditary components are contained in a single DNA molecule or chromosome that is located freely in the cytoplasm, and does not have a wall / core membrane. Prokaryotic cell types are found in bacteria and blue algae (Cyanophyceae). 1. Prokaryotic Cells Prokaryotic cells are surrounded by a cell wall, 10-20 nm thick. The cell wall is sometimes enveloped by a capsule/jelly/lender. Parts of a prokaryotic cell: a. Cell wall - Almost all prokaryotic cells have cell walls except mycoplasma. The bacterial cell wall gives the bacterial cell a certain shape, is elastic and is located between the capsule and the cytoplasmic membrane. - The main constituent material of the cell wall is mucocomplex (mucocomplex) there is a layer of peptidoglycan which is a heteropolymer consisting of amino sugar substances (acetyl glucosamine and acetyl muramic acid) and amino acids namely glutamic acid, alanine, glysin, and diaminopimelat acid or lysine. These sub-units are bound together to form a polymer. The intact cell wall also contains: teichoic acid, proteins, polysaccharides, lipoproteins and lipopolysaccharides bound to peptidoglycan. b. Inside the cell wall there is a plasmalemma membrane (cell membrane) - In certain parts of the cell membrane, it forms indentations towards the cytosol, forming structures called mesosomes similar to mitochondria in eukaryotic cells. - The plasma membrane also forms folds towards the cytosol with fine sheet-like structures along the inner membrane surface called cytomembrane lamellae, containing photosynthetic pigments. - The cytoplasmic membrane lies below the cell wall and is not tightly bound to the cell wall. Contains proteins, lipids and nucleic acids - This membrane functions in regulating the entry of food substances, the exit of metabolic waste and is selectively permeable. In addition, the membrane also plays a role in the process of dividing the cytoplasm into two parts, followed by the formation of a dividing wall. - The mechanism of transporting food substances and metabolic waste requires energy and selective properties of the membrane. The regulation is done by the enzyme permease found in the membrane. For each substance, a specific permease is required. - In prokaryotic cells, the cytoplasmic membrane is where the respiration process takes place because of the enzymes for respiration, namely the enzymes in the Krebs cycle, Enzymes in the electron transport system and cytochrome, found in the membrane. In eukaryotic cells, the enzymes for the respiration process are found in the mitochondria. - The inner part of the plasma membrane contains cytoplasm, ribosomes and nucleoids - Cytoplasm contains vacuoles, vesicles and stores sugar reserves - Ribosomes are free in the cytoplasm and are the site of protein synthesis - Nucleoid is the core region, there are chromosomes formed from DNA molecules c. Flagella, Pili and capsules - Flagella: Flagella are the means of locomotion in bacteria. All curved bacteria and some rodshaped bacteria have flagella. Locus-shaped bacteria rarely have flagella. The size of the flagella is very small and not visible with a microscope without painting. Flagella thickness between 0.02-0.1 microns, depending on the species of bacteria, while the length usually exceeds the length of the bacterial cells. Flagella consist of elastic protein material, namely flagellin, which is similar to myosin (a protein in muscles). Flagella are derived from protoplasts, not from cell walls. With electron microscopy can be seen that at the base of the flagella there is a basic granule (basal granula) that is at the place of exit from the protoplast. Based on the location and number of flagella, bacteria can be divided into 5 groups, namely : 1. Atric bacteria: bacteria that do not have flagella. 2. Monotric bacteria: bacteria that have a single flagellum at the end. 3. Lophotric bacteria: bacteria that have a beam of flagella located at one end. 4. Amphitric bacteria: bacteria that have one flagella each or one flagellum located at both ends. 5. Peritrichic Bacteria: Bacteria that have flagella located all over the cell surface.