Concept Map for Project Based Unit
Boxes shaded in pink are investigative lessons. Boxes shaded in green are benchmark lessons. Boxes shaded in yellow are concepts that were part of benchmark and investigative lessons.
Concept Narrative
The Anthropocene is the name for new geologic epoch, one that is defined by the changes made by human activity. Because there are so many humans living on Earth using a great amount of the planet's resources, humans are disrupted huge geologic cycles like the water, carbon and nitrogen cycle. As a result, there have been major changes made to the land, air and water of the planet. These changes can affect the health of a great many ecosystems, which are biological communities composed of interacting organisms and their physical environments. Similarly, biomes, which are much bigger than ecosystems, are being affected by human activity.
Food webs are demonstrations of how organisms, producers, consumers, and decomposers, are related within a particular ecosystem. Producers are known as autotrophs since they are able to make organic molecules from inorganic molecules using energy from the sun. For this reason, all plants are considered producers since they undergo photosynthesis to make their own food in the form of organic sugar molecules. Consumers eat producers or other consumers because they cannot make their own food. They must attain energy from other organisms. Decomposers are important components in ecosystems because they are responsible for breaking down organic material so that it can be reused by producers. In addition, food webs show how energy flows through an ecosystem. Energy enters ecosystems by the sun and is converted and stored in the bonds of organic sugar molecules made by plants and other producers. Energy is passed to consumers as they eat these organic molecules. However, only 10% of the organism's energy is passed to another. Most of the energy is given off as heat.
To go into more detail, photosynthesis is a process that captures energy from sunlight to make sugars that store chemical energy. Chlorophyll is a molecule in chloroplasts that absorbs some of the energy in visible light. Plants have two main types of chlorophyll that absorb mostly red and blue wavelengths of light and not much green light. As a result, the green color of plants comes from the reflection of light’s green wavelengths by chlorophyll. Chloroplasts are the membrane-bound organelles where photosynthesis takes place in plants. The two main parts of chloroplasts needed for photosynthesis are the grana and the stroma. Grana are stacks of thylakoids, which contain chlorophyll and proteins. The stroma is the fluid that surrounds the grana inside the chloroplast.
The light-dependent reactions of photosynthesis capture energy from the sunlight. These reactions take place within and across the thylakoid membrane. Water and sunlight are needed for this process. Chlorophyll absorbs energy from sunlight. The energy is transferred along the thylakoid membrane via excited electrons which enter the electron transport chain located in the thylakoid membrane. Water molecules are broken down into oxygen, hydrogen ions and electrons. Oxygen molecules are released. The hydrogen molecules are transported across the thylakoid membrane to create a concentration gradient. They flow back across the thylakoid membrane through a channel called ATP Synthase which synthesizes ATP at the same time. Energy carried along the thylakoid membrane is transferred to molecules that carry energy, such a NADPH. The light-independent reactions use energy from the light-dependent reactions to make sugars. These reactions occur in the stroma of chloroplasts. Carbon dioxide molecules are needed during this process. The carbon dioxide comes from the atmosphere and enters the plant at the stoma of the leaves. A molecule of simple sugar is formed using one 3 carbon molecules and 3 carbon dioxides. The sugar, usually glucose, stores some of the energy that was captured from sunlight. Plants need photosynthesis for their growth and development.
Cellular respiration is very related to photosynthesis, since the products of photosynthesis (oxygen and sugar) are the reactants of cellular respiration and the reactants of photosynthesis (energy, water, and carbon dioxide) are the products of cellular respiration. Because the two processes exchange carbon dioxide, both are a part of the carbon cycle within ecosystems. Plants and animals release carbon dioxide into the atmosphere as they respire. Plants use this carbon dioxide and convert it to an organic form. This form is incorporated into plants and animals until they die and decomposers break down the organic matter of organisms. In addition, the organic matter of decayed organisms can be made into fossils and fossil fuels. Carbon can be released back into the atmosphere by burning fossil fuels. Currently, humans are burning a huge amount of fossil fuels and for this reason, the cycle has become disrupted and unbalanced.
Another important nutrient cycle present with ecosystems is the water cycle. It describes the continuous movement of water on, above, and below the surface of the Earth. Water also goes through different phases (liquid, solid and gas) as it moves through the cycle. One step of the cycle is evaporation which happens when the sun heats up water in rivers, lakes, or oceans and turns it into water vapor. The water vapor becomes a part of the atmosphere. As the water vapor rises, temperatures drop and cause the water to condense and turn back into a liquid. This phase is called condensation. Precipitation occurs when there is so much condensed water that the air can no longer hold it. It falls from clouds onto the surface of the Earth in the form of rain, hail, sleet, or snow.
Food webs are demonstrations of how organisms, producers, consumers, and decomposers, are related within a particular ecosystem. Producers are known as autotrophs since they are able to make organic molecules from inorganic molecules using energy from the sun. For this reason, all plants are considered producers since they undergo photosynthesis to make their own food in the form of organic sugar molecules. Consumers eat producers or other consumers because they cannot make their own food. They must attain energy from other organisms. Decomposers are important components in ecosystems because they are responsible for breaking down organic material so that it can be reused by producers. In addition, food webs show how energy flows through an ecosystem. Energy enters ecosystems by the sun and is converted and stored in the bonds of organic sugar molecules made by plants and other producers. Energy is passed to consumers as they eat these organic molecules. However, only 10% of the organism's energy is passed to another. Most of the energy is given off as heat.
To go into more detail, photosynthesis is a process that captures energy from sunlight to make sugars that store chemical energy. Chlorophyll is a molecule in chloroplasts that absorbs some of the energy in visible light. Plants have two main types of chlorophyll that absorb mostly red and blue wavelengths of light and not much green light. As a result, the green color of plants comes from the reflection of light’s green wavelengths by chlorophyll. Chloroplasts are the membrane-bound organelles where photosynthesis takes place in plants. The two main parts of chloroplasts needed for photosynthesis are the grana and the stroma. Grana are stacks of thylakoids, which contain chlorophyll and proteins. The stroma is the fluid that surrounds the grana inside the chloroplast.
The light-dependent reactions of photosynthesis capture energy from the sunlight. These reactions take place within and across the thylakoid membrane. Water and sunlight are needed for this process. Chlorophyll absorbs energy from sunlight. The energy is transferred along the thylakoid membrane via excited electrons which enter the electron transport chain located in the thylakoid membrane. Water molecules are broken down into oxygen, hydrogen ions and electrons. Oxygen molecules are released. The hydrogen molecules are transported across the thylakoid membrane to create a concentration gradient. They flow back across the thylakoid membrane through a channel called ATP Synthase which synthesizes ATP at the same time. Energy carried along the thylakoid membrane is transferred to molecules that carry energy, such a NADPH. The light-independent reactions use energy from the light-dependent reactions to make sugars. These reactions occur in the stroma of chloroplasts. Carbon dioxide molecules are needed during this process. The carbon dioxide comes from the atmosphere and enters the plant at the stoma of the leaves. A molecule of simple sugar is formed using one 3 carbon molecules and 3 carbon dioxides. The sugar, usually glucose, stores some of the energy that was captured from sunlight. Plants need photosynthesis for their growth and development.
Cellular respiration is very related to photosynthesis, since the products of photosynthesis (oxygen and sugar) are the reactants of cellular respiration and the reactants of photosynthesis (energy, water, and carbon dioxide) are the products of cellular respiration. Because the two processes exchange carbon dioxide, both are a part of the carbon cycle within ecosystems. Plants and animals release carbon dioxide into the atmosphere as they respire. Plants use this carbon dioxide and convert it to an organic form. This form is incorporated into plants and animals until they die and decomposers break down the organic matter of organisms. In addition, the organic matter of decayed organisms can be made into fossils and fossil fuels. Carbon can be released back into the atmosphere by burning fossil fuels. Currently, humans are burning a huge amount of fossil fuels and for this reason, the cycle has become disrupted and unbalanced.
Another important nutrient cycle present with ecosystems is the water cycle. It describes the continuous movement of water on, above, and below the surface of the Earth. Water also goes through different phases (liquid, solid and gas) as it moves through the cycle. One step of the cycle is evaporation which happens when the sun heats up water in rivers, lakes, or oceans and turns it into water vapor. The water vapor becomes a part of the atmosphere. As the water vapor rises, temperatures drop and cause the water to condense and turn back into a liquid. This phase is called condensation. Precipitation occurs when there is so much condensed water that the air can no longer hold it. It falls from clouds onto the surface of the Earth in the form of rain, hail, sleet, or snow.