.1. discuss the four toxic forms of oxygen, how to detoxify them, why they are d
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Question
.1. discuss the four toxic forms of oxygen, how to detoxify them, why they are dangerous to cells, even ours.2. Presence or absence of oxygen detoxifying genes and which metabolic pathway to produce ATP is directly related to whether microorganisms are considered obligate aerobes, obligate anaerobes, facultative anaerobes, aerotolerant anaerobes, or microaerophiles. Could you make a chart to explain this phenomenom
?
3. Some microbes can nitrogen fix and some can carbon fix which is a definite advantage. Why?
4. Mineral, are trace elements, and vitamins, are growth factors, are required in small amounts for many microbes.
5. Optimum growth temperatures, pH range, osmotic pressure all effect growth how?
6. psychrophiles, mesophiles, thermophiles, hyperthermophiles – all refer to?
7. What are quorum sensing and biofilms?
10 what is the generation time>
11. Estimate population size by direct and indirect methods.
Explanation / Answer
1. The four toxic forms of oxygen are hyper oxides, peroxides, ozone and hydroxyl radicals. They are dangerous to the cell, as they destroy the cell membranes. To detoxify the free radicals enzymes such as super oxide dismutase and antioxidants are present. They convert the free radicals to water and oxygen molecules. 2. obligate aerobes - requires oxygen to grow obligate anaerobes - grow in the basence of oxygen facultative anaerobes - grow in the absence of oxygen, but can tolerate oxygen presence. aerotolerant anaerobes - very low levels of oxygen is allowed. microaerophiles - Grow in the presence of low levels of oxygen, and if concentration increases they die. For all this types, the metabolic activities vary with different enzyme conctitutents. 3. When some bacteria fix nitrogen and some carbon, these can be used to produce biofertilizers. For specific deficient element specific micobes can be used. Water logger rice plants are usually deficient in nitrogen content, then the bacteria fixing nitrogen are used and production is increased. 4. Mineral, are trace elements, and vitamins, are growth factors, are required in small amounts for many microbes, because they are constituted in the enzymes and co-factors. 5. Optimum growth temperatures, pH range, osmotic pressure all effect growth, as they indirectly effect the enzyme activity that control the reactions of metabolism. 6. psychrophiles(cold temperatures), mesophiles (normal), thermophiles(high), hyperthermophiles (very high), are the types of bacteria with different temperature tolerances. 7.Quorum sensing - It is a co ordinated behaviour between many bacteria of a colony. Biofilm - It is a aggregate of micro organisms that are adhere each other and to surface. 10. Generation time is the time taken to produce the offsprings by a bacterial colony. Time to double the population. 11. Different techniques are used to estimate the population. They are sampling, mark and recapture.Related Questions
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