Microbiology: Factors Affecting Microbial Growth pH

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What is the preferred pH range for the growth of most microorganisms?

pH 7.0-7.4 (correct)

pH 2-5

pH 8.5-10

pH 1-2

What is the primary reason why bacteria die in a hypertonic environment?

Oxygen depletion

Desiccation (correct)

Nutrient deficiency

Toxic chemicals

Which type of microorganisms prefer an acidic environment?

Alkaliphiles

Fungi

Neutrophiles

Acidophiles (correct)

Which type of microbe thrives in environments with high atmospheric pressure?

Piezophiles Signup and view all the answers

What is the result of osmosis on a human cell, such as a red blood cell?

Crenation Signup and view all the answers

What is the term for microorganisms that prefer salty environments?

Halophilic Signup and view all the answers

What is the term for the movement of a solvent through a permeable membrane?

Osmosis Signup and view all the answers

What percentage of oxygen do microaerophiles require?

5% oxygen Signup and view all the answers

What happens to obligate anaerobes in the presence of oxygen?

They are killed Signup and view all the answers

What is the result of osmosis on a bacterial cell?

Plasmolysis Signup and view all the answers

What is the typical atmospheric pressure in which most bacteria thrive?

14.7 psi Signup and view all the answers

What is the effect of plasmolysis on bacterial cell growth and multiplication?

It inhibits growth Signup and view all the answers

What is the term used to describe microorganisms that have complex nutritional requirements?

Fastidious Signup and view all the answers

What type of medium is prepared in the laboratory by adding specific amounts of each component?

Chemically defined medium Signup and view all the answers

Which type of medium contains ground up or digested extracts from animal organs and plants?

Complex medium Signup and view all the answers

What is the purpose of enriched media in microbiology?

To promote the growth of fastidious organisms Signup and view all the answers

What type of pathogens will not grow on artificial culture?

Obligate intracellular pathogens Signup and view all the answers

What is the term used to describe media that are prepared in the laboratory?

Artificial media Signup and view all the answers

What is the primary function of a selective medium in microbiology?

To inhibit the growth of certain organisms Signup and view all the answers

What is the purpose of MacConkey agar in microbiology?

To differentiate between Gram-positive and Gram-negative bacteria Signup and view all the answers

What is the primary difference between sterilization and disinfection?

Sterilization destroys all microorganisms, while disinfection reduces the number of microorganisms Signup and view all the answers

What is the purpose of differential media in microbiology?

To differentiate between various types of microorganisms Signup and view all the answers

Which of the following is an example of a situation where microbial growth is encouraged?

Culturing microorganisms in a laboratory Signup and view all the answers

What is the purpose of sanitization in microbiology?

To reduce the number of microorganisms Signup and view all the answers

Which of the following sterilization methods involves the use of steam under pressure?

Autoclaving Signup and view all the answers

What is the primary purpose of disinfection in healthcare settings?

To eliminate most or all pathogens, except bacterial spores Signup and view all the answers

What is the term for reducing microbial populations to safe levels in public health settings?

Sanitization Signup and view all the answers