Questions and Answers
An organic nutrient that cannot be synthesized by an organism and must be provided is called:
An important mineral ion that stabilizes the cell membrane and ribosome is:
The term autotroph refers to an organism that:
The methanogens require environments that:
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Organisms that feed on dead organisms for nutrients are called:
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The movement of molecules from an area of high concentration to low concentration is called:
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Diffusion of water through a semi-permeable membrane is called:
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Bacteria living in a freshwater stream that are moved to salty seawater will:
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Which of the following require the cell to use energy?
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An organism with a temperature growth range from 45-60 degrees C is called:
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The time interval from parent cell to two new daughter cells is called:
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The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is called:
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Growth factors are:
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Nutrient absorption is mediated by the:
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Facilitated diffusion is limited by:
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In which condition will the cell wall protect the cell from bursting?
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Aerobic respiration is an example of:
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Calcium is essential for bacteria because:
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In the viable plate count method, each __________ represents one __________ from the sample.
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The E. coli that normally live in the large intestine and produce vitamin K is:
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Superoxide ion is toxic to strict anaerobes because they lack:
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Which of the following is true of passive transport?
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Which of the following statements is true for all organisms?
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Psychrophiles would be expected to grow:
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Study Notes
Nutrient and Cell Requirements
- Growth factors are organic nutrients that organisms cannot synthesize and must obtain from their environment.
- Magnesium is an important mineral ion that stabilizes cell membranes and ribosomes.
- Autotrophs utilize CO2 as their carbon source for growth.
- Methanogens thrive in anaerobic environments rich in hydrogen gas and CO2.
Organism Classification and Nutrient Interactions
- Saprobes decompose dead organisms for nutrients.
- Diffusion refers to the movement of molecules from areas of high concentration to low concentration.
- Osmosis is specifically the diffusion of water across a semi-permeable membrane.
- Freshwater bacteria exposed to salty seawater will shrivel due to osmosis.
Energy and Transport Mechanisms
- Endocytosis requires cellular energy for material uptake.
- Thermophiles have optimal growth temperatures between 45-60 degrees Celsius.
- Generation time is the interval for a parent cell to divide into two daughter cells.
- The stationary phase of bacterial growth occurs when multiplication and cell death rates are equal.
Cellular Structures and Functions
- Growth factors cannot be synthesized by organisms and are essential for growth.
- Nutrient absorption primarily occurs through the cell membrane.
- Facilitated diffusion is limited by the availability of carrier proteins in the membrane.
- A hypotonic environment protects cells from bursting by exerting pressure against the cell wall.
Metabolic Pathways and Symbiotic Relationships
- Aerobic respiration exemplifies chemoheterotrophy, where organisms obtain energy by consuming organic compounds.
- Calcium is crucial for stabilizing the bacterial cell wall.
- In the viable plate count method, each colony corresponds to a single species from the original sample.
- Commensal E. coli assist in vitamin K production in the human intestines without causing harm.
Reactive Oxygen Species and Transport Mechanisms
- Strict anaerobes are vulnerable to superoxide ions as they lack dismutase, an enzyme to neutralize these reactive species.
- Passive transport requires a concentration gradient for molecules to move and does not utilize energy.
- All organisms necessitate growth factors, either for enzyme function or structural integrity.
Temperature Preferences of Microorganisms
- Psychrophiles are adapted to grow at or near freezing temperatures, thriving where most organisms cannot.
Closing Remarks
- Understanding these fundamental concepts is essential for studying microbiological growth, interaction, and metabolism.
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Test your knowledge on essential microbiology concepts with these flashcards. Each card contains key terms and their definitions, ensuring an engaging study experience focused on critical nutrients and their functions in organisms. Perfect for students preparing for Microbiology Test 2.