Write notes on :
(a) mitochondria (b) antibiotics
(c) harmful bacteria (d) useful bacteria
Write notes on :
(a) mitochondria (b) antibiotics
(c) harmful bacteria (d) useful bacteria
(a) Mitochondrion is a membrane−enclosed organelle found in eukaryotic cells. Mitochondria are responsible for the production of most of the energy (or ATP) in cells. Therefore, they are also known as the power house of cells. A mitochondrion is composed of two lipid membranes enclosing the matrix. The inner membrane gets folded to form numerous cristae. Cristae are the main site for ATP production. Mitochondrial matrix contains mitochondrial DNA and ribosomes.
(b) Antibiotics are medicines produced by certain microorganisms to kill other disease−causing microorganisms. These medicines are commonly obtained from bacteria and fungi. Streptomycin, tetracycline, penicillin etc. are the common antibiotics. Microorganisms have certain biochemical pathways, which are needed for their survival such as respiration, cell−wall formation and enzyme synthesis. Antibiotics bind with the precursors needed for these pathways, and block them. In the absence of essential life processes, the microorganisms are killed. For example, penicillin blocks the cell−wall formation in bacterium. As a result, the bacterium is killed.
(c) There are some bacteria that can cause disease in plants and animals, while some can spoil food. These bacteria are called harmful or pathogenic bacteria. For example, Staphylococcus aureus bacteria grows on food stuff and produces a toxin called enterotoxin. Eating food stuff spoilt by this bacterium can result in food poisoning. Some bacteria cause diseases in plants such as rust of wheat, which results in the loss of yield. In animals, bacteria cause many diseases such as anthrax that may also result in the death of the animal.
(d) There are some bacteria that are helpful to humans such as:
(i) A bacterium Lactobacillus, promotes the formation of curd. Such bacteria are used in food industry for pickling, curd making etc.
(ii) Bacteria like Rhizobium help to increase the soil fertility by fixing the atmospheric nitrogen.
(iii) Bacteria also play an important role in the preparation of medicines. Antibiotics are chemicals produced by bacteria to kill other bacteria. For example, Streptomycin.
(iv) Certain bacteria are also used in the biological treatment of sewage and industrial effluents.
(a) Mitochondrion is a membrane−enclosed organelle found in eukaryotic cells. Mitochondria are responsible for the production of most of the energy (or ATP) in cells. Therefore, they are also known as the power house of cells. A mitochondrion is composed of two lipid membranes enclosing the matrix. The inner membrane gets folded to form numerous cristae. Cristae are the main site for ATP production. Mitochondrial matrix contains mitochondrial DNA and ribosomes.
(b) Antibiotics are medicines produced by certain microorganisms to kill other disease−causing microorganisms. These medicines are commonly obtained from bacteria and fungi. Streptomycin, tetracycline, penicillin etc. are the common antibiotics. Microorganisms have certain biochemical pathways, which are needed for their survival such as respiration, cell−wall formation and enzyme synthesis. Antibiotics bind with the precursors needed for these pathways, and block them. In the absence of essential life processes, the microorganisms are killed. For example, penicillin blocks the cell−wall formation in bacterium. As a result, the bacterium is killed.
(c) There are some bacteria that can cause disease in plants and animals, while some can spoil food. These bacteria are called harmful or pathogenic bacteria. For example, Staphylococcus aureus bacteria grows on food stuff and produces a toxin called enterotoxin. Eating food stuff spoilt by this bacterium can result in food poisoning. Some bacteria cause diseases in plants such as rust of wheat, which results in the loss of yield. In animals, bacteria cause many diseases such as anthrax that may also result in the death of the animal.
(d) There are some bacteria that are helpful to humans such as:
(i) A bacterium Lactobacillus, promotes the formation of curd. Such bacteria are used in food industry for pickling, curd making etc.
(ii) Bacteria like Rhizobium help to increase the soil fertility by fixing the atmospheric nitrogen.
(iii) Bacteria also play an important role in the preparation of medicines. Antibiotics are chemicals produced by bacteria to kill other bacteria. For example, Streptomycin.
(iv) Certain bacteria are also used in the biological treatment of sewage and industrial effluents.
