Microbial Growth Curves and Environmental Factors

A set of vocabulary flashcards covering key terms and definitions related to microbial growth curves and environmental factors affecting organisms.

Open System

A system that has unlimited resources and does not build up waste products.

Closed System

A system that has limited resources, accumulates waste products, and allows population growth that follows a specific growth curve.

Lag Phase

The initial phase of growth where organisms sense their environment and prepare for growth.

Exponential Growth Phase

The phase of growth characterized by optimal conditions leading to rapid population increase.

Stationary Phase

The phase where resources are scarce, and the population size stabilizes due to balance between birth and death rates.

Death Phase

The phase where resources are very scarce, waste is toxic, leading to a higher death rate than reproduction.

Thermophiles

Organisms that thrive in high temperatures, often near or above boiling.

Mesophiles

Organisms that thrive at moderate temperatures, typically between 20°C and 45°C.

Psychrophiles

Organisms that thrive in cold environments, usually at temperatures below 20°C.

Obligate Aerobes

Organisms that require atmospheric levels of oxygen to survive.

Facultative Anaerobes

Organisms that prefer oxygen for growth but can survive without it.

Obligate Anaerobes

Organisms that find oxygen toxic and require an oxygen-free environment.

Microaerophiles

Organisms that require low levels of oxygen to survive.

Aerotolerant Anaerobes

Organisms that grow equally well in the presence or absence of oxygen.

pH

A measure of acidity or alkalinity of a solution that affects microbial growth.

Acidophiles

Organisms that thrive in acidic environments with a low pH.

Neutrophiles

Organisms that prefer neutral pH environments.

Alkaliphiles

Organisms that thrive in alkaline/basic environments with high pH.

Halophiles

Organisms that thrive in high-salt environments (2-40% salt).

Halotolerant

Organisms that can tolerate low levels of salt (1-2% salt).

Barophiles

Organisms that thrive under high pressure, often found on the ocean floor.

Radiophiles

Organisms that thrive in radioactive environments.

Reactive Oxygen Species (ROS)

Highly reactive molecules formed by the breakdown of oxygen that can damage cell structures.

Superoxide Dismutase (SOD)

An enzyme that helps protect organisms from damage caused by reactive oxygen species.

Catalase

An enzyme that converts hydrogen peroxide into water and oxygen, protecting cells from oxidative damage.

Environmental Factors

Conditions that can influence the growth and survival of microorganisms.

Diversity of Microbes

The vast variety of different microbial species found in various environmental conditions.