Monera
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Basic Monera Information
Structure
The most unique thing about monerans is that they are prokaryotes. Since they are prokaryotes, they don’t have nuclei or the different organelles of eukaryotes. Prokaryotes have a “naked” chromosome made up of one DNA molecule without some of the proteins found in eukaryotes. Some prokaryotes have small circular pieces of DNA called plasmids in addition to the major chromosome. The cell walls of most prokaryotes have a polysaccharide modified by polypeptides, or peptidoglycans.
Motility
Flagella are made up of the globular protein flagellin organized in helixes. Flagellas are small protrusions coming out of prokaryotes that give it motility, or the ability to move. Prokaryotes without flagella move in a corkscrew motion. Others may also glide through the slimy materials they secrete.
Origins
Monerans originated such a long time ago that there are no obvious characteristics that we can use to separate their different species. Transformation, the uptake of free DNA and transduction, the transport of DNA by viruses could have switched around the genes of different types of prokaryotes.
Gram positive/ negative
The kingdom Monera is split up into two different groups called archaebacteria and eubacteria. There is a way to stain Monera to distinguish whether it has one of the two types of cell walls, gram positive or gram negative, and see what groups of Monera it belongs in. Bacteria are stained in with a violet dye and iodine, rinsed in alcohol, and then stained again with a red dye. The structure of the cell wall reveals the response. Gram-positive bacteria have cell walls with a lot of peptidoglycans, which traps the violet dye. Gram-negative bacteria have less peptidoglycans, which is between the plasma membrane and the outer wall. The violet dye easily rinses off the cell, but the red color stays on.
Nutrition
Prokaryotes are usually classified according to what they eat. Autotrophs metabolize the chemicals in their own bodies. They can harvest light (photosynthesis) or various nonliving substances (chemiosynthesis). Heterotrophs eat substances made by autotrophs. Parasites trap their energy form the tissues of the host cell they live on. Saprobes (decomposers) get their energy form dead and decaying materials.
Gas Exchange
Prokaryotes are also distinct because they can live whether or not there’s oxygen in the atmosphere. Obligate aerobes need oxygen to live, while obligate anaerobes can only lie without oxygen. A facultative anaerobe can switch between the two as it has adapted to both environments.
Reproduction
Monerans reproduce sexually and asexually. Asexual reproduction takes place by binary fission, when there’s favorable condition, or if there are unfavorable conditions, endospore production happens. Sexual reproduction is by conjugation of neighboring cells. In this process, the two cells transfer DNA through a connected bridge.