Microorganisms and Metals for Growth

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Which term is used to describe all chemical reactions involved in maintaining the living state of cells and the organism?

Anabolism

Nutrition

Catabolism

Metabolism (correct)

What is the primary function of catabolism in metabolic reactions?

Stabilize ribosomes, membranes, and nucleic acids

Synthesize nucleic acids and phospholipids

Build larger molecules using energy

Break molecular structures down and release energy (correct)

What is the role of sulfur in bacterial cells?

Helps stabilize cell walls

Required for enzyme activity

Key element in proteins and nucleic acids

Present in amino acids like cysteine and methionine (correct)

Which macronutrient is required by enzymes for activity?

Potassium (K) (C) Signup and view all the answers

What is the function of calcium in microbes?

Helps stabilize cell walls (D) Signup and view all the answers

What role do micronutrients play in microbial physiology?

Act as cofactors for enzymes (B) Signup and view all the answers

Which type of dye is typically used to stain endospores in the classical endospore-staining protocol?

Malachite green (B) Signup and view all the answers

How are endospores typically observed in cells that have been stained with basic dyes?

As unstained regions (B) Signup and view all the answers

In which genera of bacteria are endospores typically formed?

Nearly 20 genera (B) Signup and view all the answers

What is significant about the capacity to produce endospores from a phylogenetic perspective?

It is found only in a specific sublineage of gram-positive bacteria. (B) Signup and view all the answers

What type of bacteria exhibit diverse physiologies despite their capacity to form endospores?

Endospore-forming bacteria include anaerobes, aerobes, phototrophs, and chemolithotrophs. (A) Signup and view all the answers

What is the purpose of following aseptic technique in microbiology?

To prevent contamination during manipulations (B) Signup and view all the answers

Why are airborne contaminants mentioned as a common problem in laboratories?

Because laboratory air contains microorganisms (A) Signup and view all the answers

What is the primary function of endospores in bacterial survival?

To function as survival structures in unfavorable conditions (D) Signup and view all the answers

Which stage of the bacterial life cycle does an endospore represent?

Dormant stage (B) Signup and view all the answers

Why do endospores form in bacteria?

When growth ceases due to lack of essential nutrients (C) Signup and view all the answers

What allows an endospore to remain dormant for extended periods?

Resistance to unfavorable conditions (C) Signup and view all the answers

What is the major role of iron in cellular respiration?

Acting as a key component of cytochromes and Fe-S proteins (B) Signup and view all the answers

Under anoxic conditions, in which form is iron generally found?

Ferrous (Fe2+) (D) Signup and view all the answers

What do cells produce to obtain iron from insoluble mineral forms?

Siderophores (iron-binding agents) (D) Signup and view all the answers

Which organic compounds are required in small amounts by certain organisms?

Vitamins, amino acids, purines (B) Signup and view all the answers

What are culture media in the context of growing microorganisms?

Nutrient solutions used to grow microorganisms in the laboratory (A) Signup and view all the answers

What distinguishes defined media from complex media?

Exact composition is known for defined media (A) Signup and view all the answers

What is the purpose of using enriched medium in microbiological culture?

To culture fastidious microorganisms (B) Signup and view all the answers

How does a selective medium differ from a differential medium in microbiological culture?

Selective medium inhibits some microbes but not others, while differential medium contains indicators to detect reactions. (C) Signup and view all the answers

Why is it important to know the nutritional requirements of a microbe in microbiological culture?

To supply proper nutrients in a culture medium (C) Signup and view all the answers

What is the purpose of adding agar to solid media in microbiological culture?

To immobilize cells and allow visible colony growth (A) Signup and view all the answers

What is the significance of aseptic technique in microbiological culture?

To prevent unwanted organisms from entering the culture media (B) Signup and view all the answers

What defines a pure culture in microbiology?

A culture with only one kind of microbe present (C) Signup and view all the answers