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Micro lesson 3
microbiology
Question | Answer |
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Microorganism (Microbe) structure | Internal structure is comprised of cellular organelles, within which are the following principle components: mitochondria, lusosomes, centrioles, microtubules, and filaments |
Mitochonndria | the major energy producing part of the cell, small and granular. encased within a membrane-like structure. contain enzymes shape ranges from spherical to rod-shaped. Inner matrix and outer envelope |
Outer envelope of mitochondria | comprised of an inner and outer electron-dense membranous component whereas the inner portion is coated with cristae (projections which go inward toward the matrix) |
Mitochondria's matrix | an amorphous (fine granular) substance contains DNA, RNA, and frequently also ribosomes. |
Lysosomes | Membrane-encased organelles considered to be the most responsible for inter-cellular digestion. contains digestive enzymes, exact role in the cell depends upon the type of cell |
Primary Lysosomes | those which have already begun enzymatic processes. encompas phagosomes, substances with engulfed liquid and solid particles broken off from the cell membrane |
Secondary Lysosomes | Those which have not begun enzymatic processes. encompass a variety of structures including: multivascular bodies, residual bodies, autosomes, heosiderin granules and lipofuscin granules. result from the fusion of a primary lysome and a vacuole |
centrioles | Short, fibrous rod-shaped organelles, centrioles comprised of nine sets of three microtubules each. existing in pairs referred to as diplosomes, centrioles are located near the nucleus |
Responsibilities of centtrioles include | -determining polarity during the late prophase and metaphase stages of cell division - capable of migrating to a site below the cell membrane, playing a pivitol role in the creation of such cellular estensions as basal bodies, cilia, flagella |
Microtubules (cytoskeleton) | the name for both straight and slightly curved organelles found in almost every cell, fulfill several key functions: maintain cell shape and aide in intercellular transport. during cell division, help redirect chromosomes to opposite ends of cells |
Combined, both microtubules and filaments are responsible for four major functions | --(cytoskeleton) determins the shape of the cell--(cytoskeleton) gives rigidity and tensile strenght to cell helps move organelles around cell--part of cell division allow chromosomes to separate into daughter cells--motility via flagella or amoeboid mvmt |
Microorganisms (Microbes): Varieties of shapes | While a microorganism's cell wall can establish the shape of a microbial cell, it is the surrounding environmental conditions which have the ability to change it |
The shapes of microorganisms include | cocci and rods |
Cocci | shperes that divide once to produce diplococci and divide more than once to produce a chain. either divide regularly in 2 planes at right angles make a standare cuboidal packet of cells or divide in 2 planes at different angles make a cluster of cells |
Rods | (straight are bacilli; spiral are spirilla) are cylinders with more surface area than cocci |
Microorganisms' shapes offer such advantages to the cell | cocci-more resistant to drying than rods, -rods more surface area take in diluted nutrients from the environment-spiral corkscrew motion less resistant to movement-square break down exstreme slinities (salt build-up) |
Microorganisms: classification | Based upon the taxonomic five kingdom system, microorganisms are divided into the following 3 kingdoms: monera, protista, fungi |
Monera | Unicellular organisms that lack nuclear membranes. The majority of monerans reproduce by binary fission |
Protista | includes several phylogenetically distinct groups all simple eukaryotes. like more complex eukaryotes, contain membrane-bound organelles with a defined nucleus. not organized into complex tissues |
fungi --------------------------------------exoskeletons of arthropods, reflects the close relationship between fungi and animalia kingdoms. closely related to each other than they are to plants. | encompass eukaryotic, mostly multicellular organisms with an unusual form of multicellularity. Cells are not entirely divided by cell walls, cytoplasm and nuclei able to flow between individual cells. cell walls made of 'chitin' a protein found in the |