Microbiology Test 2 Flashcards

Questions and Answers

An organic nutrient that cannot be synthesized by an organism and must be provided is called:

Water

Trace element

Growth factor (correct)

Element

Micronutrient

An important mineral ion that stabilizes the cell membrane and ribosome is:

Zinc

Calcium

Magnesium (correct)

Iron

Potassium

The term autotroph refers to an organism that:

Must obtain organic compounds for its carbon needs

Does not need a carbon source

Gets energy by oxidizing chemical compounds

Gets energy from sunlight

Uses CO2 for its carbon source (correct)

The methanogens require environments that:

Are anaerobic with hydrogen gas and CO2 Signup and view all the answers

Organisms that feed on dead organisms for nutrients are called:

Saprobes Signup and view all the answers

The movement of molecules from an area of high concentration to low concentration is called:

Diffusion Signup and view all the answers

Diffusion of water through a semi-permeable membrane is called:

Osmosis Signup and view all the answers

Bacteria living in a freshwater stream that are moved to salty seawater will:

Shrivel Signup and view all the answers

Which of the following require the cell to use energy?

Endocytosis Signup and view all the answers

An organism with a temperature growth range from 45-60 degrees C is called:

Thermophile Signup and view all the answers

The time interval from parent cell to two new daughter cells is called:

Generation time Signup and view all the answers

The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is called:

Stationary phase Signup and view all the answers

Growth factors are:

Cannot be synthesized by organisms Signup and view all the answers

Nutrient absorption is mediated by the:

Cell membrane Signup and view all the answers

Facilitated diffusion is limited by:

Carrier protein in the membrane Signup and view all the answers

In which condition will the cell wall protect the cell from bursting?

Hypotonic Signup and view all the answers

Aerobic respiration is an example of:

Chemoheterotrophy Signup and view all the answers

Calcium is essential for bacteria because:

Stabilizes cell wall Signup and view all the answers

In the viable plate count method, each represents one from the sample.

colony, cell Signup and view all the answers

The E. coli that normally live in the large intestine and produce vitamin K is:

Commensal Signup and view all the answers

Superoxide ion is toxic to strict anaerobes because they lack:

Dismutase Signup and view all the answers

Which of the following is true of passive transport?

It requires a concentration gradient Signup and view all the answers

Which of the following statements is true for all organisms?

They require growth factors Signup and view all the answers

Psychrophiles would be expected to grow:

At freezing temperature Signup and view all the answers

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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Description

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.