Useful Links & Vocabulary
Unit 2--Matter and Energy (Ecology Quizlet)
TEA Food chains, Food Webs, and Energy Pyramids
Organic Compounds Vs. Inorganic Interactive
TEKS:
7.5 Matter and Energy. The student knows that interactions occur between matter and energy. The student is expected to:
Learning Outcomes :
Students will know...
-photosynthesis transforms radiant energy into chemical energy (food).
-energy powers life processes.
-energy changes form as it flows through living systems (not cycled). matter cycles within living systems.
-the decay of biomass releases energy as heat.
-organic compounds contain carbon and hydrogen and may contain other elements.
Students will be able to...
-recognize that radiant energy from the Sun is transformed into chemical energy through the process of photosynthesis
-identify that organic compounds contain carbon and other elements such as hydrogen, oxygen, phosphorus, nitrogen or sulfur
-demonstrate and explain the cycling of matter in living systems, including food chains, food webs, and energy pyramid
-diagram the flow of energy through living systems
Essential Questions
1. How is energy from the sun transformed into chemical energy through the process of photosynthesis?
2. How does energy flow through living systems?
3. How does matter cycle within living systems?
4. How does the flow of energy contrast to the cycling of matter in living systems?
5. What elements do organic compounds contain?
Organic Compounds (Organic Compound Activity from TEA)
Molecules can be either organic or inorganic. Compounds are molecules that have more then one kind or element within its structure. In chemistry terms, organic means that a molecule has a carbon backbone, with some hydrogens thrown in for good measure. Elements that bond with the carbon-hydrogen pair include: oxygen, nitrogen, phosphorus and sulfur.
Living creatures are made of various kinds of organic compounds.
Inorganic molecules are composed of other elements. They can contain hydrogen or carbon, but if they have both, they are organic.
You may be wondering why carbon plays such a big role in life. Well, wonder no more! The reason is that carbon has 4 electrons in its outer shell, but, deep down, it really wants 8 electrons instead. Think of carbon as the jack-of-all-trades. Carbon's potential to form many kinds and combinations of bonds with many different atoms gives rise to all sorts of molecules of varying shapes and sizes. Living organisms have definitely taken advantage of this ability, which might explain the similarity between the words "organic" and "organism."
Therefore: · All organic compounds [carbohydrates, fats, proteins] contain the element carbon bonded to hydrogen. Many also contain oxygen. Organisms also use nitrogen, phosphorus and sulfur to form cells and tissues. (SPONCH) · Organic compounds are formed by producers that use carbon dioxide from the air and water from the soil to make food in the process of photosynthesis.
VIDEO CLIP : Carbon, Organic Compounds and the Ecosystem
Photosynthesis:
Photosynthesis is one of the most important chemical processes on Earth. Pine trees have evolved to grow in a triangular shape in order to expose most of its needles to the sun to capture as much light as possible so photosynthesis can occur and the tree can continue to grow.
What’s it all about?
Plants are the beginning of life on Earth. Many food chains start with a plant. A plant does not eat food to get energy, like you do, but instead creates it from sunlight, water and carbon dioxide. In addition to creating their own energy using photosynthesis plants also recycle the air, taking carbon dioxide in and producing oxygen for you to breathe. Photosynthesis is a process that takes the light from the sun and converts it into energy for food. Photosynthesis occurs in all the green parts of a plant, with the leaves typically being the greenest. In order for a plant to photosynthesize it needs carbon dioxide, water and sunlight. They use these three things to create oxygen and glucose, the food energy to keep the plant going. Photosynthesis takes place inside chloroplasts, which contain chlorophyll. The chlorophyll is what absorbs the light energy needed to make photosynthesis happen. Leaves typically have a large surface area in order to collect a lot of light. The water a plant needs is obtained through the roots. Roots have little hair cells that project out from the root into the soil to increase the surface area of the root system resulting in more collection of water. The last ingredient in the photosynthesis equation is carbon dioxide; plants get carbon dioxide from the air through their leaves. The carbon dioxide moves in through the stomata. Photosynthesis is an essential process for life.
What does it mean?
Chloroplast - specialized organelles that are the food producers of the cell, and are only found in plant cells. They contain a network of membranes embedded into a liquid matrix and are the home of chlorophyll
Chlorophyll - a greenish pigment found in almost all plants which allows plants to trap energy from the sun
Stomata - small openings in the underside of the leaf that allow oxygen and carbon dioxide to move in and out. (authored by Wonderville)
Food chains
All living things (plants, animals, bacteria, etc.) need energy to live, and all living things get this energy from food. A food chain shows how energy and nutrients are transferred from one organism to another in the form of food. This food must then be turned into the energy the organism needs to live by a process called respiration. A food chain shows the transfer of energy from one organism to another. The arrows point to the organism that receives the energy. These arrows are called strands.
Plants, algae and some types of bacteria make their own food using the sun's energy to combine carbon dioxide (CO2) and water into a food called glucose. They are called producers because they produce or make their own food. Organisms that get their energy from consuming other organisms are called consumers.
Organisms that consume producers are called primary consumers. Organisms that consume primary consumers are called secondary consumers. Organisms that consume secondary consumers are called tertiary consumers, and so on.
Some organisms consume by absorbing food (ex. fungi and bacteria). Some organisms consume by eating with special adaptations called mouths (and sometimes teeth or beaks). Organisms that eat plants are called herbivores (herb = plant, vore = to eat) Cows and deer are herbivores, as are many insects. They are also primary consumers (because they eat producers).
Organisms that eat other animals are called carnivores (carne = meat, vore = to eat). Owls are carnivores because they eat rodents and birds. Some insects are carnivores. If a carnivore eats an herbivore, it is also called a secondary consumer. Depending on what organism it eats, a carnivore may also be a secondary, tertiary, quaternary (and so on) consumer. Owls and shrews are both carnivores. Because the owl eats the shrew, this is an example of a tertiary consumer eating a secondary consumer.
Organisms that eat both plants and animals are called omnivores. People are omnivores, and so are rats, raccoons, & skunks. So... is an omnivore a primary, secondary or tertiary consumer? Well, it depends on what it's eating at the moment. If it's eating grass, it is a primary consumer. But when it's eating a rabbit, it's a secondary consumer. And when it eats a salmon (that eats insects and crustaceans), it's a tertiary consumer. But, usually, we rank them at the highest level of consumption on average. So a deer will always be a primary consumer, and an owl can be a 5th level consumer.
Organisms that break down dead or decaying organisms for their food are a special kind of consumer called detritivores and decomposers. All detritivores are decomposers because they both consume dead organisms. But not all decomposers are detritivores. Detritivores (detrit = wear down into bits, vore = to eat; have mouths and eat dead bits of plants and animals. Some examples include worms and certain insects (pill bugs, millipedes). Decomposers that don't have mouths to eat with, break down or digest dead organisms using special enzymes and then absorb the nutrients (like a sponge absorbs water). Some examples of decomposers include fungi and bacteria.
[Click here to go to a website that explains the parts of a food chain]
[See if you can tell the difference between a producer, consumer and decomposer in this game.]
Remember: Each consumer in the food chain gets their energy in the form of food by eating another organism - except producers, which make their own food.
When you draw a food chain, you then always begin with a producer. Don't forget, the arrows should point to the organism doing the consuming because the energy is transferred into that organism. See the picture above for an example.
Food Webs
A food web is composed of interconnecting food chains.
Because organisms in a habitat generally eat more than one thing, the energy produced in plants connects with several organisms living together. For example, an owl eats many types of rodents, including rats, voles, shrews and birds. Since shrews eat insects, and rats and birds are omnivores, you can see that the food chains become interconnected and more complex.
You can learn about energy transfer of the organisms in different habitats when you click on the food web picture on the left AND you may click on this link to play with more food webs.
Energy Pyramid
1. Each stage/level of the pyramid is called a "trophic level," or the position an organism occupies in a food chain. Each trophic level is shared by organisms that occupy the same position in a food chain.
2. As you go up the trophic pyramid, the total number of organisms at the next level decreases from the previous level.
3. The trophic pyramid shows that some, but not all, energy is transferred from one trophic level to the next.
a. Organisms use energy to grow and move (Metabolic activity = all the things your cells do to help you live).
b. 90% of the food an organism makes (in the case of a producer) or consumes (in the case of a consumer) is changed back into energy that is used by that organism to live. The remaining 10% of the food is used to grow (or make biomass), SO the next organism that eats it only receives 10% of the original energy. For example, calories is a measure of food energy. A plant might make 100 calories of its own food by photosynthesis. It will use 90 calories to live and 10% to grow. When an herbivore eats that plant, it will only get 10 of the original calories that the plant made. That herbivore will use 9 of those 10 calories for its own metabolism. If a carnivore eats that herbivore, it will receive only 1 of those calories from the original 10 that the herbivore got. Because energy is lost as you go up the trophic pyramid, there are fewer numbers of consumers as you go up the pyramid.
4. Trophic levels
a. The bottom level of the trophic pyramid is made up of the producers. Producers are organisms that make their own food. These include plants and algae that use the energy of the sun to make their own food. It also includes certain types of bacteria that use chemicals (instead of the sun) to make their own food. These bacteria live near underwater volcanoes that are so deep in the ocean that no sunlight can penetrate and they live in total darkness.
b. Primary consumers - All consumers get their energy by consuming other organisms. Organisms that consume producers are called primary consumers, because they get their food from organisms in the first trophic level (producers).
c. Secondary consumers are consumers that consume primary consumers.
d. Tertiary consumers are consumers that consume secondary consumers, and so on.....*
5. You can also have higher trophic levels (fourth and fifth) depending on the food chain you are looking at. For example,
algae --- plankton ----small fish ----large fish-----human----shark (or shark--- human!) (You might see that the arrows are missing. That's because I can't figure out how to make them and I don't have time right now!!! I hope you remember by now how to make the arrows. Remember that each arrow is called a strand)
6. Omnivores are organisms that eat producers and other consumers. Because we are talking about the transfer of energy to different trophic levels, an omnivore is a primary consumer when it is eating a producer and a secondary consumer when it is eating a primary consumer and a tertiary consumer when it is eating a secondary consumer, and so on. When putting the organism on a trophic pyramid, we place it on the highest trophic level that they are consuming at.
7. Detritivores and decomposers can also be primary, secondary, and tertiary consumers depending on which level of the trophic pyramid they are eating from. Decomposers include bacteria and fungi and detritivores. Bacteria and fungi consume by absorbing their food, while detritivores such as worms get their energy by eating dead and decaying organisms. A worm that eats a dead plant is a primary consumer, while a worm that eats a dead deer is a secondary consumer. On a trophic pyramid, we put place the decomposers along the side of the pyramid (as seen in your homework and notes).
(courtesy of Mrs. Rothenhausler)