Module 3: ENERGY FLOW AND BIOGEOCHEMICAL CYCLES

energy

Almost every process important to life (living systems) depends on a steady flow of __________

flow of energy

The ____________ is the essence of life, specifically, of living systems. Energy is the ability to do work, and it is everywhere.

Mechanical
Radiant
Sound
Chemical
Heat
Electrical
Nuclear

By now, you have some excellent ideas of what energy is. You may best recall different forms of energy as:

kinetic
potential

Energy can be possessed in two ways, either as ______ or ________ energy

renewable
non-renewable

Energy may also be sourced from _________ or __________ sources

non-renewable resources

____________________ supply the bulk of our energy needs because technologies allow them to be harnessed on a large scale to meet consumer needs

useful

Regardless of its source, the energy contained in the source is changed into a more ______ form.

Laws of Thermodynamics

The ____________________ are the basis of the flow of energy

Law of Conservation of Energy

the ______________________, concerns the amount of energy in the universe

Law of Conservation of Energy

It states that the amount of energy in the universe is constant. It may be changed from one form to another but cannot be created or destroyed.

Law of Entropy

It states that disorder (entropy) in the universe is increasing. As energy is used, more and more of it is converted into heat, the energy of random molecular motion.

Energy

”capacity for doing work”

Law of Entropy

Moreover, energy cannot be changed without some conversion into heat energy.

Energy

found everywhere (as potential or kinetic) and flows in the ecosystem

heat energy

Thus, as energy is changed from one form to another, part of that energy assumes waste form (________________)

decreased
higher
lower

Consequently, after transformation, the capacity of energy to do work is ______. Thus, energy flows from ______ to ______ levels.

sun

The primary source of energy is the ____

2%
photosynthesis

How much of this is transformed into chemical energy? On average, only ___ of the total light striking a leaf surface is used to make food through ___________, while most of it is transformed as heat

photosynthesis
chemosynthesis
eating/digesting

energy is obtained by living things in three ways through ________, ____________, or _________ other living or dead organisms by heterotrophs

photoautotrophs

___________ like algae, plants, and photosynthetic bacteria that harness radiant energy and convert it to chemical energy in the form of ATPs (adenosine triphosphates) to be used to synthesize complex organic molecules like glucose

algae
plants
photosynthetic bacteria
ATP

photoautotrophs like _____, ______, and _______ that harness radiant energy and convert it to chemical energy in the form of ______ to be used to synthesize complex organic molecules like glucose

Autotrophs

___________ are the foundation of every ecosystem on Earth. _______* form the base of food chains and food webs, and the energy they capture from light or chemicals sustains all the other organisms in the community.

Chemoautotrophs

__________________ are organisms that create their organic food from inorganic chemicals like iron, nitrogen, sulfur, and magnesium and, in turn, supply energy to the rest of the ecosystem.

Heterotrophs

____________ cannot capture light or chemical energy to make food and thus, mainly rely on autotrophs.

trophic levels

It is a feeding level, often represented in a food chain or food web.

trophic levels

relative position of an entity in the food chain

Primary producers
primary consumers
secondary consumers
tertiary consumers

_____________ constitute the bottom trophic level, followed by ________ (herbivores), ____________, __________, et cetera.

heat
metabolic processes

Energy flows within these food chains, and as it moves up the trophic levels, some of it is dissipated as ______ because organisms carry out ______________.

10%
respiration
growth
reproduction

Only about ____ of net energy production at one trophic level is passed on to the next level because processes like ______, _____, ______, et cetera reduce energy flow

Consumers

________ often convert high-quality food sources into new tissue more efficiently than low-quality food sources.

decomposers

The low energy transfer rate between trophic levels makes _______ generally more important than producers in energy flow

decomposers

process large amounts of organic material and return nutrients to the ecosystem in inorganic form, which is then taken up again by primary producers.

Ecological pyramids

_____________, also referred to as trophic pyramids, are graphical representations designed to show relationships between energy and trophic levels in an ecosystem

quantity of individuals
biomass
energy

In ecological pyramids, Often, the ____________, ________, or ______ at each given trophic level demonstrates these relationships

Pyramid of numbers
Pyramid of biomass
Pyramid of energy

3 types of ecological pyramids

pyramid of energy

Among these three types, the most useful is the ___________ because it shows the relationship between energy and trophic level.

food webs
food chains

Energy is passed from one organism to another through _______ and their constituent ________

biological magnification
biomagnification

As energy passes from one trophic level to another, we need to address the important environmental consequence of increasing the concentration of persistent, toxic substances at each trophic level, from the primary producers to the different consumer levels. It is known as ________________ or _______

bioaccumulate

Many substances _________, and notable among them is the pesticide dichlorodiphenyltrichloroethane (DDT), which have been shown to accumulate in eagles and raptors in the US, causing detrimental effects on their reproduction where they formed thin-shelled eggs that broke in their nests

one direction
sunlight
heat

Energy flows in ________ through ecosystems, entering as _______ (or inorganic molecules for chemoautotrophs) and leaving as _____ during the many transfers between trophic levels.

closed system

Earth is a ________ for matter; thus, all elements needed for living systems came from what was present in the Earth's crust so many billion years ago.

Elements

_________ are the critical components of life and must be available for biological processes.

biogeochemical cycle

Because geology and chemistry have significant roles in studying these processes, recycling inorganic matter between living organisms and their environment is called a ___________.

biosphere

These cycles move chemicals through the _______, passing them through organisms and the ________’s abiotic components like the atmosphere, marine, fresh waters, soils, and rocks.

transformation
transfer
storage
functioning
link
regulate

These cycles are important because they:
1) enable the __________ of matter from one form to another, which enables the utilization of matter in a form specific for a particular organism;
2) enable the ______ of molecules from one locality to another;
3) facilitate the _____ of elements;
4) assist in the _______ of ecosystems;
5) _____ living organisms with living organisms and living organisms with abiotic factors, and
6) _______ the flow of substances.

Radiant energy

________ powers process like photosynthesis and evaporation. It also drives the cycles that involve reservoirs where chemicals are stored or concentrated for long periods.

closed system

Earth has many biogeochemical cycles illustrating that our planet is a ________. Elements are recycled and not replenished from outside sources.

carbon
hydrogen
oxygen
nitrogen
phosphorus

There are five most common elements associated with organic molecules that are vital components of life:

hydrologic cycle

It is essential to recognize that the cycling of these elements is interconnected. For instance, the leaching of nitrogen or phosphorus into bodies of water is affected by the ______________.