Biology 20: Unit A-Energy & Matter in the Biosphere: Topic 1

Energy Transfer in the Biosphere

Ecology

The study of the relationship between living things and their environment

Biosphere

Part of Earth in which life exists including lithosphere, atmosphere, and hydrosphere

System

An object/group of objects a scientist chooses to study.

Open System

Energy & Matter can enter and leave

Closed System

Energy can enter & leave, matter cannot

1st law of Thermodynamics

Energy cannot be created or destroyed

How much of the Earth's energy comes from the sun?

100%

Albedo

Refers to the amount of energy reflected by clouds, water, and land. Always expressed as a %

___% is reflected by clouds, land, ocean

30

___% is absorbed by gasses (warms up the atmosphere)

19

___% reaches the surface (absorbed by land and water)

51

Only ___% is used for photosynthesis

1

The path of energy flow through our biosphere

Sun

Producers

Organisms that can produce their own food

Autotrophs

Self

Producer Examples

Plants, single

Photosynthesis

Process by which producers convert energy from the sun into chemical potential energy (glucose)

Chemical Equation of Photosynthesis

6 H2O(l) + 6 CO2(g) + energy + chlorophyll

Chemical Energy

Stored in the bonds of carbohydrate molecules (known as glucose, sugar)

Chemosynthesis

Process in which microorganisms use hydrogen sulfide molecules to produce their own carbohydrate based energy

Chemical Equation of Chemosynthesis

CO2 + 4 H2S + O2

Chemosynthesis produces:

Sulfuric Acid & Water

Chemical energy released from chemosynthesis is used for:

Glucose production

When is chemosynthesis used?

When there is no sunlight

Who uses chemosynthesis?

Organisms in extreme conditions, or in the dark

Cellular Respiration

Consumers convert chemical energy stored in glucose bonds into ATP

ATP

Molecules which serve as our body's main fuel source

ATP gets used for:

Kinetic & Thermal Energy

Consumers

An organism that obtains energy and nutrients by feeding on other organisms or their remains

Heterotroph

An organism that cannot make its own food

Cellular Respiration Chemical Equation

C6 H12 06(aq) + 6O2(g)

Primary Consumers

Organisms that eat plants (herbivores)

Primary Consumer Examples

insects, grazing mammals, some birds/fish

Secondary Consumers

Organisms that mainly EAT herbavores (can be omnivores or carnivores)

Secondary Consumer Examples

Spiders, frogs

Tertiary Consumers

Organisms that mainly eat other carnivores (true carnivores)

Tertiary Consumer Examples

Lion,wolves, eagles

Decomposers

Organisms that absorb leftover or waste matter

Decomposer Examples

Fungi, Bacteria

Food Chain

A linear pathway of energy transfer, generally 3

Food Web

All feeding relationships, shows connections between many food chains

Trophic Levels

Refer to the feeding levels in an ecosystem through which energy and matter are transferred

The 1st Trophic Level

Provides ALL the chemical energy required to fuel the other trophic levels

Where do decomposers sit in regards to trophic levels?

Anywhere

2nd law of thermodynamics

With each conversion of energy, there is less energy available to do useful work

Energy lost with each conversion does not disappear. What happens to it?

It is converted to an unuseful form of energy

The largest amount of energy is found…?

In the first trophic level

Organisms at the top consume…?

FAR MORE than organisms at the bottom of the food chain in order to obtain adaquate amounts of energy

Food chains have limits because

There is a finite amount of energy available

Food Webs

Show how some organisms feed at multiple trophic levels. Arrows always point in the direction of energy flow

Rule of 10

Each level of a food chain receives 10% of the energy from the level below it, thus, 90% of energy is lost with each step

Pyramid of Numbers

Each bar of the pyramid represents the number of organisms in each trophic level.

Pyramids of Biomass

Represents the dry mass of living organisms per unit area (in g/m2). This pyramid takes into account, the actual size of organisms in an ecosystem rather than just the number, can be inverted

Biomass

How much something weighs with no water in it

Pyramids of Energy

Shows the total amount of energy that is transferred through each trophic level (J or Kg), they are always upright because they can never be less energy in a lower trophic level

Bioaccumulation

The accumulation of a substance, such as a toxic chemical, in various tissues of a living organism. Affects higher trophic levels the most

Weather

Refers to conditions that occur to a particular place at a particular time

Climate

The average weather conditions that occur in a region over a long period of time. Usually a minimum of 30 years.

Biotic

living things

Abiotic

Non

atmosphere

A layer of gases surrounding Earth, the most abundant gas in our atmosphere is nitrogen, oxygen is the second most, and then the other ones are in such small amounts that they are difficult to measure.

Lithosphere

The solid portion of the Earth, composed of rocks, minerals, and elements. Home to many micro organisms, plants, and animals. (Crust & Mantle)

Hydrosphere

All of the water on earth, whether it is liquid, water vapour or ice.

___% of water on earth is saltwater

97

___% of water on earth is freshwater

3