RNA

RNA Structure and function: The tertiary structure of RNA is similar to DNA, but there are several important differences: RNA usually forms intramolecular base pairs the information carried by RNA is not redundant because of these intramolecular base pairs. the major and minor grooves are less pronounced the structural, informational adaptor and information transfer roles of RNA are all involved in decoding the information carried by DNA The 4 types of RNA tRNA (transfer RNA) mRNA rRNA snRNAtRNA tRNA is the information adapter molecule. It is the direct interface between amino-acid sequence of a protein and the information...

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Paramecium

The paramecium is larger than the amoeba. It can be found in ponds with scum on them. It has more of a shape than an amoeba, looking like the bottom of a shoe. It is covered with tiny hairs that help it move. These hairs are called cilia. The paramecium is able to move in all directions with its cilia. The paramecium eats tiny algae, plants, etc. The cilia propel the food into a tiny mouth opening of the paramecium. The food is then shoved down a little tube called a gullet that leads to the protoplasm or stuffing of the cell. The food is held in little cells called vacuoles. It has two other vacuoles at either end of its body to get rid of...

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Posted in: Microbiology

Tobacco mosaic virus (TMV)

TMV was the first virus to be discovered by the Dimitri Ivanowski in 1892 and crystallized by the W.M Stanley. It causes mosaic disease in tobacco plant. It belongs to tobamo virus group. It is rod shaped, containing no envelope measuring about 300nm in length and 15-17 nm in diameter. It has a protein capsid constituting of 95% of virus and a core of nucleic acid. The capsid is in the form of a tube with a cavity measuring about 2nm in diameter. It is composed of 2130 identical capsomers which are closely packed and arranged in the form of a regular spiral or helix. There are about 49 capsomers for every 3 turns that is about 16 per turn...

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Microsystis

Kingdom: Monera Division: Cynophysia Class: Cynophyceae Order: Chrococcales Family: Chrococcaceae Genus: Microsystis Microsystis is a free floating or planktonic blue green algae commonly found in fresh water bodies such as ponds pools lakes, etc. which maybe contaminated by sewage water. It generally forms dense water grooms. It is colonial form and the colonies are irregular. Each colony consists of a large number of densely packed small cells that are evenly distributed through out a common thin watery, gelatinous matrix. On mucilaginous matrix which is colourless and homogenous. The colony has many air space also called pseudo vacuoles...

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Economic importance of genus Aspergillus.

Aspergillus has both harmful ans useful activities from the view of the human.Harmful activitiesMany species of Aspergillus such as A. glqaus A.flavus A. repns are responsible of spoilage of exposed food stuff like jams, jellies, bread, tobacco and many other product like leather & textiles. Many of the species are pathogenic to animals as well as human beigns. A. flavus, A. fumigates and A.niger causes diseases of respiratory tracks commonly refered to as aspergilloses. Aspergilloses is reported in birds, cattle, sheep, horses and human begins. Symptoms of Aspergillosis resembles those...

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Posted in: Microbiology

Saccharomyces

Class: Acromycetes Order: Endomycetales Family: Saccharomycetaeceae Genus: Saccharomyces Saccharomyces is saprophytic fungi (Yeast) found growing abundantly in sugary substance such as fruits, syrups, jams, nectar, honey, toddy etc. it is uni-cellular but sometimes the cell may remain attached giving the appearance of a pseudo mycelium. the cells are small oval or spherical in shape and grow as white or creamy colonies on the surface of solid nutrient media. Each cell has a definite two layered cell wall made up of fungal cellulose with the chitin. The cell wall encloses the protoplasm which can be differentiated into outer ectoplasm and...

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Posted in: Microbiology

Aspergillus

Class: Acromycetes Order: Aspergillales Family: Aspregillaceae Genus: Aspergillus Aspergillus is a wide spread fungus generally saprophytic and growing stale bread , fruits, vegetables, jams, jellies, foot wear etc. a few species of Aspergillus are parasitic causing lung disease (aspergillosis) and ear infection (outomycosis). The mycelium consists of a hyaline branched, septate and multi nucleated hyphae. Most of the mycelium grows above the substratum. Some hyphae grow deep into the substratum and halt in the distribution of nutrient and encouraged. REPRODUCTION ASEXUAL REPRODUCTION Asexual reproductionFrom the vegetative mycelium...

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Posted in: Microbiology

Penicillium

Class: Acromycetes Order: Aspergillales Family: Aspregillaceae Genus: Penicillium Penicillium is commonly called blue mold. It is a saprophytic found growing in decaying fruits and vegetables, especially citrus fruits-like orange and lemon. The mycelium consists of pale hyaline brightly hyphae which generally grow superficially on the substratum, the hyphae are septate branched and uni- nucleated. REPRODUCTION ASEXUAL REPRODUCTION It is for the formation of conidia on special branch called conidiopores. The conidiophores is the long, slender septate grows right from the vegetative hyphae . They maybe branched or unbranched. The ultimate...

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Posted in: Microbiology

Rhizopus

Class: Zygomycetes Order: Mucorales Family: Mucoraceae Genus: Rhizopus Rhizopus is commonly called bread molds. It is a saprophytic fungus found growing on bread, jam, pickles, decaying vegetables and fruits etc. the plant body consists of white cottony mycelium growing over the substratum. The young mycelium consists of long aseptate coenocytic hyphae. The older mycelium has three types of hyphae 1. Stolons : they are staut cylindrical creeping hyphae . They are differentiated in to nodes and inter nodes. 2. Rhizoidal hyphae: it produces at the node of the stolon .they are highly branched and penetrated into substratum .they...

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Posted in: Microbiology

Pythium

Class: OomycetesOrder: PeronosporalesFamily: PythiaceaeGenus: PythiumPythium is a mold of cosmopolitan distribution and consisting of about 45 species which maybe aquatic or terrestrial inhabits. It is facultative parasite on fresh water algae and seedling of many plants like mustard, papaya, tobacco, beans, ginger, etc. it also occurs saprophytic ally in moist soil. Pythium infects the host plant by the wounds. It is also responsible for the “damping- off” disease of seedling. It is also causes “soft rot”,”root rot” etc. it is also involved in decay and decomposition of the plant remains in the soil. The mycelium...

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Posted in: Microbiology

Gracilaria

Class: Rhodophyceae Order: Graclariales Family: Gracilariaceae Genus: GracilariaGracilaria is common marine red algae found growing attached to the sub-stratum such as rocks by a basal cushion disc, (lithophytes). It has large dichotomously branched thallus also called fronds. It is composed of closely compacted vertical thread like fronds which are which are dark red or pink branches reaching up to 50cm in height. The matured thallus shows little anatomical difference and T.S of the thallus shows three zones. They are peripheral layer of cell, cortex and medulla. The peripheral layer of cell is small uni or multi nucleated, some of them...

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Posted in: Microbiology

Cosmarium

Class: chlorophceae Order: Zygnematales Family: Desmidiaceae Genus: Cosmarium Cosmarium is a uni-cellular fresh water desmids occurring in ponds, rich in organic decaying matter, along with other free-floating algae. Usually it occurs in abundance in mucilaginous masses along the wall of reservoirs and water tanks especially in winter' The cell posses a distinct median constriction called sinus. This divides them in to two distinct halves called semi- cells. Which remains join together by a connecting zone called isthmus. Each semi-cell maybe circular, elliptical or oval in shape. The cells posses a three layered transversely segmented...

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Posted in: Microbiology

Anabaena

Kingdom: Bacteria Division: Cyanophyta Class: Cyanophyceae Order: Nostocales Family: Nostocaceae Genus: Anabaena Anabaena is the filamentous form found occurring either in the single filament or as free-floating colonies or in a delicate means the stratum in permanent or semi- permanent form. Some spices of anabaena are endophytic and have within roots of circus and aquatic pteriodophyte azolla. The Trico are the same thickness through out, sometimes slightly alternated at the typical ends. They are straight cercinated or irregularly contorted concurringly with a hyaline watery sheet. The cells are usually spherical or barrel shaped .they...

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Posted in: Microbiology

Basic Structure of an Amino Acid

Basic Structure All amino acids found in proteins have this basic structure, differing only in the structure of the R-group or the side chain. The simplest, and smallest, amino acid found in proteins is glycine for which the R-group is hydrogen (H). L-isomerIn proteins, only the L-isomer is found normally. As you travel onward (from the carbonyl carbon to the amino group), the R group of L-amino acids will be on the left as shown in the molecular graphic on the right Essential amino acids Humans can produce 10 of the 20 amino acids. The others must be supplied in the food....

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Posted in: Biotechnology

Scenedesmus

Scenedesmus is a widely distributed green algae found freely in stagnant water. It appears in pure culture in aquarium and in jar containing standing uncharged water in the laboratory. It is colonial form with a number of cells in the coenobium (colony) being multiplies of two usually 4-8 cells. The cell are ellipsoidal or fusiform in shape and arranged in single or double series with long axis, parallel to one another so as to form a flat or curve plain. The two end cells of the coenobium may differ from the shape of the others and often teeth or spines or gelatinous bristles, which are projections of the mucilaginous cell envelope .each...

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Posted in: Microbiology

Spirulina

Spirulina is a planktonic blue green algae found growing in fresh water bodies, sewages etc. it consists of a unicellular trichrome’ which is helically or spirally twisted and hence the name Spirulina. Each cell is typically cyanophyceae and is bounded by the cell wall enclosing the protoplasm and is differentiated in to outer pigmented chromoplasm consisting of the pigment phycocyanin and chlorophyll which give the green colour to the algae . The inner centroplasm consists of the incipient nucleus. Reserved food materials such as cyanophytin starch, cyanophytin granules (protein) and oil globules are present in the cytoplasm Reproduction...

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Posted in: Microbiology

Chlorella

Chlorella is a green algae generally found to occur as a plankton in fresh water bodies and damp walls, rocks etc. The thallus is unicellular some times growing small groups and colonies. Each cell is small cylindrical or ellipsoidal in shape. The cell is surrounded by 3 layered cell wall. The wall shows the presence of sporopollinin. Each cell posses a single large cup shaped chloroplast which is parietal in position. The cells are unicellular. The nucleus lies in the chloroplast cup, other cell organelles like mitochondrion, ribosome etc are present. Asexual reproduction takes place by the formation of non-motile autospores. Two to sixteen...

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Posted in: Microbiology

Spirogyra

Spirogyra commonly called “pond silk” occurs in extensive muscles in living bright green free floating algae on the surface of stagnant ponds’ slowly running streams and fresh water streams. The thallus or plant body consists of long slender thread like un-branched filaments which are slimy to touch due to mucilage on there outer wall .A cell enlargedEach filament is composed of a single raw of similar cylindrical cells. Each cell consists of a cell wall made up of cellulose and protein in definite within the cell wall is a parietal layer of protoplasm enclosing a large central vacuoles. In the protoplasm is embedded 1-14 chloroplast.Each...

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Posted in: Microbiology

The Influenza (Flu) Virus

ext to the common cold, influenza or "the flu" is perhaps the most familiar respiratory infection in the world. In the United States alone, approximately 25 to 50 million people contract influenza each year. The symptoms of the flu are similar to those of the common cold, but tend to be more severe. Fever, headache, fatigue, muscle weakness and pain, sore throat, dry cough, and a runny or stuffy nose are common and may develop rapidly. Gastrointestinal symptoms associated with influenza are sometimes experienced by children, but for most adults, illnesses that manifest in diarrhea, nausea, and vomiting are not caused by the influenza virus though...

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Posted in: Microbiology

The Human Immunodeficiency Virus (HIV)

Perhaps no disease is more strongly identified with the late twentieth century than acquired immunodeficiency syndrome, commonly known as AIDS. Yet, according to a 2004 United Nations report on the state of the global AIDS epidemic, the disease has not yet begun to reduce its grip on the world population despite the fact that AIDS does not generally receive the same amount of public attention as it once did. On the contrary, infections are on the rise in many countries, including high income nations such as the United States. In 2003, nearly five million people contracted the human immunodeficiency virus (HIV) that causes AIDS, the greatest number...

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Posted in: Microbiology

Plant Cell Structure

Plants are unique among the eukaryotes, organisms whose cells have membrane-enclosed nuclei and organelles, because they can manufacture their own food. Chlorophyll, which gives plants their green color, enables them to use sunlight to convert water and carbon dioxide into sugars and carbohydrates, chemicals the cell uses for fuel. ...

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Posted in: Microbiology

Bacteria Cell Structure

They are as unrelated to human beings as living things can be, but bacteria are essential to human life and life on planet Earth. Although they are notorious for their role in causing human diseases, from tooth decay to the Black Plague, there are beneficial species that are essential to good health....

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Posted in: Microbiology

Animal Cell Structure

Animal cells are typical of the eukaryotic cell, enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall. This feature was lost in the distant past by the single-celled organisms that gave rise to the kingdom Animalia. Most cells, both animal and plant, range in size between 1 and 100 micrometers and are thus visible only with the aid of a microscope. The lack of a rigid cell wall allowed animals to develop a greater diversity of cell types, tissues, and organs. Specialized cells that formed nerves and muscles—tissues impossible...

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Posted in: Microbiology

Introduction to Cell and Virus Structure

At first glance, the petal of a flower or the skin on the back of a human hand may seem smooth and seamless, as if they were composed of a single, indistinct substance. In reality, however, many tiny individual units called cells make up these objects and almost all other components of plants and animals. The average human body contains over 75 trillion cells, but many life forms exist as single cells that perform all the functions necessary for independent existence. Most cells are far too small to be seen with the naked eye and require the use of high-power optical and electron microscopes for careful examination. The relative scale of...

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Posted in: Microbiology