Vocab list

First law of thermodynamics

The fundamental principle stating that energy cannot be created or destroyed in an isolated system. It can only change from one form to another, such as from potential energy to kinetic energy, illustrating the conservation of energy.

Second law of thermodynamics

This law describes how energy is transferred in a food chain, indicating that during energy transformations, some chemical energy is inevitably transformed into heat energy, resulting in decreased efficiency at each trophic level.

Efficiency

A measure of how effectively a process converts input energy into useful work output. It is expressed as a ratio, comparing the amount of useful energy produced to the total energy consumed.

Entropy

A quantitative measure of disorder within a physical system. In thermodynamic processes, an increase in entropy signifies a reduction in the energy available for doing work, leading to less organized states.

Energy transformations

The process through which energy changes its form, such as converting chemical energy stored in food into kinetic energy when an organism moves or performs work.

Photosynthesis

The biological process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose, some of which can be stored as biomass for energy use.

Cellular respiration

A metabolic process where cells break down glucose and other organic molecules to release usable energy, typically in the form of adenosine triphosphate (ATP), for biological activities.

Consumer (heterotroph)

An organism that cannot synthesize its own food and obtains organic substance by feeding on other organisms, whether plants or animals.

Trophic level

The hierarchical position that an organism occupies within a food chain or food web, reflecting its role in energy transfer and nutrient cycling.

Producer

An autotrophic organism that synthesizes its own food from inorganic substances, primarily through the process of photosynthesis, serving as a primary energy source in an ecosystem.

Productivity

The rate at which energy is converted into biomass over a specific time period, typically measured as mass per unit area per unit time, indicating ecosystem health and efficiency.

Gross productivity (GPP)

The total rate of biomass production in a given area over a specific time period, representing the overall energy captured by producers before any losses due to respiration or other processes.

Net productivity (NPP)

The remaining energy or biomass in an ecosystem after accounting for energy lost through respiration, indicating the amount of energy available for growth and reproduction.

Biocides

Chemical substances that eliminate, inhibit, or control harmful organisms, including disinfectants used to eradicate pathogens and pesticides designed to protect crops from pests.

Ecological pyramids

Graphical representations that illustrate the quantitative distribution of biomass or energy among different trophic levels in an ecosystem, providing insights into ecosystem structure and efficiency.

Bioaccumulation

The process through which certain substances, particularly pollutants, accumulate in the tissues of living organisms over time, leading to harmful concentrations within individuals.

Biomagnification

The increasing concentration of non-biodegradable pollutants at successive trophic levels of a food chain, due to the loss of biomass as energy is transferred up the chain.

Heterotroph

An organism that depends on consuming other organisms for energy and nutrients, unable to create its own food through photosynthesis or chemosynthesis.

Autotroph

Organisms capable of producing their own nourishment through either photosynthesis or chemosynthesis, including plants and certain types of bacteria.

Photoautotroph

Organisms, such as green plants and algae, that leverage sunlight to produce energy through the process of photosynthesis, converting light energy into chemical energy.

Chemoautotroph

Microorganisms that derive energy from inorganic chemical reactions, such as those occurring in deep-sea vents, utilizing this energy to synthesize organic compounds.

Primary productivity

The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs into organic substances, providing a foundational energy source for the ecosystem.

Gross primary productivity (GPP)

The total amount of energy captured by photosynthetic organisms in an ecosystem per unit area per unit time, representing the total energy input into the ecosystem.

Net primary productivity (NPP)

The amount of energy or biomass that is available for the next trophic level after plants have utilized some energy for their own respiration and metabolic processes.

Gross secondary productivity (GSP)

The total energy or biomass gained by consumers through the assimilation of food, calculated by subtracting energy lost in feces from the total energy obtained from food.

Net secondary productivity (NSP)

The energy or biomass gained by consumers per unit area per unit time, after accounting for the energy lost during respiration, representing the biomass available for growth.

Biomass

The total mass of living matter within a given area or volume, encompassing all organic material found in both producers and consumers within an ecosystem.

Standing crop

The current biomass present in an ecosystem, representing the amount of organic material at a specific point in time and indicating overall ecosystem productivity.

Pyramid of biomass

A graphical model depicting the amount of biomass at each trophic level within an ecosystem, illustrating the distribution and availability of organic material.

Pyramid of numbers

A representation that shows the number of individual organisms present at each trophic level, providing insight into population dynamics within an ecosystem.

Pyramid of energy/productivity

A diagram that illustrates the flow of energy or productivity differences between trophic levels, emphasizing how much energy is available at each successive level.