3.2 Energy, Producers, and Consumers and 3.3 Energy Flows in Ecosystems

3.2 Energy, Producers, and Consumers

Primary Producers

Basically, organisms need energy for growth and reproduction. Without energy, there would be no life on earth. Energy comes from the sunlight, which is the most ultimate source of energy. It's impossible for an organism to create energy. Autotrophs are organisms who use solar/chemical energy to produce food by assembling inorganic compounds into complex organic molecules. They also store energy, so that other organisms can eat them. 

Primary sources are energy compounds that are later used by other organisms. They are the key essential to the flow of energy. 

Energy from the Sun
Photosynthesis, captures energy from light, and uses it to power chemical reactions that covert carbon dioxide+water which would equal carbohydrates+oxygen. Without photosynthesis, you wouldn't be able to breathe. 

Life Without Light

Chemosynthesis, is chemical energy used to produce carbohydrates. It is usually found deep in the ocean, or in a harsh enviroment. Biologists found organisms around volcanic vents on the deep ocean floor, with no light for photosynthesis. With no light, they tried to research what the primary sources were, which is chemosynthesis. 

Consumers

Consumers are also known as heterotrophs, because they have to get energy and nutrients from other organisms, and deeply rely on it. They are animals, fungi, bacteria, etc. that can't use energy from the enviroment as their primary sources. There are also more than one groups of consumers.

-Carnivores=kill and eat other animals

-Herbivores=absorbs energy by eating plant leaves, roots, seeds, and fruits. 

-Scavengers=eat food that has been killed by predators or have already died.

-Omnivores=eat both animals and plants.

-Decomposers=feed by chemically breaking down organic matter. Recycles nutrients.

-Detritivores=digest decomposers that live on detritus particles. Chews and grinds them into very small pieces. (snails, shrimp, worms, crabs, mites, etc.)

Consumer categories don't explain the real complexity of nature. Organisms in nature usually do not stay inside their categories the ecologists place them in. The food chain/ web is very complex, the one's we see are simplified.

3.3 Energy Flows in Ecosystems

Food Chains and Food Webs

A food chain is a series of steps in which organisms transfer energy by eating and being eaten. Food chain's vary in length. 

Phytoplankton are aquatic food chains, primary producer of floating algae. 

Food Webs and Disturbances

Food webs are difficult to predict how exactly they would respond to an enviromental change. Enviromental disturbances happen, and it really effects the food webs in a terrible way by messing everything up. Effects of disturbances can be dramatic.

Zooplankton are krill, which is a small group of swimming animals that feed on marine algae. 

Recently, krill has been slowly becoming extinct and dropping population. At the same time, huge amounts of ice around antarctica in the sea has been melting. With less ice, there is a result of fewer algae that grow beneath. 

Trophic levels and Ecological Pyramids

Ecological pyramids show amount of energy within each trophic level. 

Pyramids of energy

small portion of energy that passes a trophic level, is stored in body of organism on next level. The remainder is considered heat. 

-Pyramids of Biomass=total ammount of living tissue within a trophic level

-Pyramids of numbers=to know the number of organisms on each level.

Section 3.2- Energy, Producers, and Consumers.

Section 3.2- Energy, Producers, and Consumers.

Vocabulary-

Autotroph: and organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer.

Primary producer: the first producer of energy-rich compounds that are later used by other organisms.

Photosynthesis: a process used by plants and other autotrophs to capture light and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches.

Chemosynthesis: a process in which chemical energy is used to produce carbohydrates.

Heterotroph: an organism that obtains food by consuming other living things; also called a consumer.

Consumer: an organism that relies on other organisms for its energy and food supply; also called a heterotroph.

Carnivore: and organism that obtains energy by eating animals. Ex: snakes, dogs, cats, river otter.

Herbivore: an organism that obtains energy by eating only plants. Ex: cows, caterpillars, and deer.

Scavenger: and animal that consumers the carcasses of other animals. Ex: king vulture.

Omnivore: and organism that obtains energy by eating both plants and animals. Ex: humans, bears, pigs, white-nosed coati.

Decomposer: an organism that breaks down and obtains energy from dead organic matter. Ex: bacteria and fungi. The decay caused by decomposers is part of the process that produces detritus- small pieces of dead and decaying plant and animal remains.

Detritivore: an organism that feeds on plant and animal remains and other dead matter. Ex: mites, snails, shrimp, crabs. Commonly digest decomposers that live on, and in, detritus particles.

Primary Producers-

• Living systems operate by expending energy
• Organisms need energy for growth, reproduction, and their own metabolic processes.
• Sunlight is the ultimate energy source.
• For some organisms, chemical energy stored in inorganic chemical compounds serves as the ultimate energy source for life processes.
• Only algae, certain bacteria, and some plants can capture energy from sunlight or chemicals and convert it into forms that living cells can use. (Those organisms are called autotrophs).
• Autotrophs use solar or chemical energy to produce “food” by assembling inorganic compounds into complex organic molecules. Also called primary producers.
• Primary producers are the first producers of energy-rich compounds that are later used by other organisms.
• So, primary producers and essential to the flow of energy through the biosphere.

Energy From the Sun-

·         The best known and most common primary producers harness solar energy through the process of photosynthesis. (See photosynthesis definition).

• Photosynthesis adds oxygen to the air and removes carbon dioxide, so without photosynthetic producers, the air would not contain enough oxygen for people to breathe.
• Plants are the main photosynthetic producers on land.
• Algae fill that role in freshwater ecosystems and in the sunlit upper layers of the ocean.
• Photosynthetic bacteria (cyanobacteria) are important primary producers in ecosystems such as tidal flats and salt marshes.

Life Without Light-

• Deep-see ecosystems depend on primary producers that harness chemical energy from inorganic molecules such as hydrogen sulfide.
• Those organisms carry out a process called chemosynthesis. (See chemosynthesis definition).
• Chemosynthetic organisms are not only found in the deepest, darkest ocean. Some chemosynthetic bacteria live in harsh environments, like deep-sea volcanic vents or hot springs.

Comparing Photosynthesis and Chemosynthesis-

            Plants use the energy from sunlight to carry out the process of photosynthesis. Other autotrophs, like sulfur and bacteria, use the energy stored in chemical bonds in chemosynthesis. So, in both processes, energy-rich carbohydrates are produced.

Consumers-

  

• Animals, fungi, and many bacteria cannot directly harness energy from the environment as primary producers do. They are known as heterotrophs, which are also called consumers. (See heterotroph and consumer definitions).

Types of Consumers-

• Carnivores, herbivores, scavengers, omnivores, decomposers, and detritivores. (See definitions).

Beyond Consumer Categories-

• Categorizing consumers is important, but the categories don’t often express the real complexity of nature.
• For example, herbivores that eat different plants parts often differ greatly in the ways they obtain and digest their food because seeds and fruits are rich in energy and nutrients and easy to digest, while leaves are poor in nutrients and hard to digest.
• Organisms in nature often don’t stay inside the categories ecologists place them in.
• For instance, some animals described as carnivores, will scavenge if they get a chance. and many aquatic animals eat a mixture of algae, bits of animal carcasses, and detritus particles.
• So the categories make a good place to start talking about ecosystems, but it is important to expand on this topic by discussing the way that energy and nutrients move through ecosystems.

Chapter 1.1

          Vocabulary:

Science- an organized way of gathering and analyzing evidence about the natural world

Scientific Methodology- involves observing and asking questions, making inferences and forming hypothesis, conducting controlled experiments,  collecting and analyzing data, and drawing conclusions.

Observation- the act of noticing and describing events or process in a careful and orderly way.

Inference- a logical interpretation based on what scientists already know.

Hypothesis-  a scientific explanation for a set of observations that can be tested in ways that can support or reject it.

Controlled experiment- in an experiment, only one variable should be changed. the rest of the variables should remain untouched, or controlled.  

Independent variable- a variable that’s deliberately changed

Dependant variable- the variable that is observed and that changes in response to the independent variable.

Control group- exposed to the same conditions as the experimental group except for one independent variable.

Data- Information

                                                                                                                                                                                                                                                                                                                          

          What science is and is not

Facts Change. Science is not set in stone. Scientific ideas are open to testing, discussion, and revision.

          Science as a way of knowing

Science is a way of thinking. It is a process, not a thing. Science deals only with the natural world. (no supernatural phenomena.)

Scientists propose explanation based on evidence, not belief.

          The goals of science

From a scientific perspective, all objects in the universe are governed by universal natural laws.

          Science, change, and uncertainty

Most of nature is a mystery because science never stands still. What was discovered today could be changed tomorrow.

          Observing and asking questions

“think something nobody has thought yet, while looking at something everybody sees.” with a little imagination, you yourself could discover something new if you thought of it in a new way.

Designing controlled experiments

Testing a scientific hypothesis often involves designing experiments that keep track of things that can change, or variables.

Collecting and analyzing data

Ÿ  Quantitive data are numbers obtained by counting and measuring

Ÿ   Qualitive data are descriptions that involve characteristics that cannot be counted

When an experiment isn’t possible

Sometimes, you cant have an experiment. An example of a case like that is given in the book, where it says that you need humans to control an experiment. But say you want to see if cancer is created in the human body when the man is exposed to a certain element. That would be a deadly experiment to conduct.  Instead, they search for people who have already been exposed to the element. For controls, they study people who have not been exposed to the element. However they use people who don’t have any medical conditions or a genetic problem.

Or another case, such as field observation, or observing an animal. First the researchers would need to study the behavior of  animals from a certain species and than write a hypothesis, than they test.

STS 4 Texting

We will be creating our own class version of the textbook.  I am hoping this will help you immensely.  Again this is for you, written by you.

Each time a reading is assigned, a texter will be assigned to summarize the section of reading assigned.  It will be your job to explain this section as well as you possibly can so that the whole class can read your summary and feel as though they understand the main points of the section.  Feel free to include any visuals that would help bring clarity and understanding you the section.