This project was one of the most interesting STEM projects so far. Our group was assigned to find a species or ecosystem in need of protection and come up with a plan to raise awareness about the species/ecosystem. We chose to raise awareness about green sea turtles. To raise awareness and help in putting a solution in place, we held a beach cleanup at Ocean Beach in San Francisco.
Concepts:
Photosynthesis is the process of turning light, water and carbon dioxide into energy in the form of glucose. Most autotrophs use photosynthesis. Photosynthesis takes place in the chloroplast of the plant cell. The equation for photosynthesis is as follows 6CO2 + 6H20 + Light = C6H12O6(glucose) + 602. The process of photosynthesis has two different steps that have to occur.
Light Dependent Reaction: Occurs in the thylakoid membranes in the chloroplast. This step uses H2O and light to make O2, ATP and NADPH.
Light Independent Reaction/Carbon Fixation: This reaction happens in the stroma of the chloroplast. This reaction uses ATP, NADPH and CO2(Carbon dioxide) to make glucose.
Cellular Respiration: The process that makes glucose into ATP, which cells use for energy. To get energy, most organisms have to eat autotrophs to get their supply of glucose. After they obtain glucose, they use this process. The equation for cellular respiration is C6H12O6 + 6O2 = 6C02 + 6H2O + ATP. Cellular respiration has three steps that need to happen.
Glycolysis: Glycolysis is the first step and it occurs in the cytoplasm without any oxygen. It uses one glucose molecule and 2 ATP and creates 2 pyruvate molecules, 2 ATP, and 2 NADH.
Krebs Cycle: The Krebs cycle is the next step in cellular respiration. The Krebs cycle happens in the mitochondria and needs oxygen, it uses the pyruvate molecules and NADH from glycolysis to make FADH2 and NADH. It also makes CO2 as waste, which is why organisms breath out CO2.
Electron Transport Chain: The electron transport chain is the last step in cellular respiration. It occurs in the mitochondria and needs oxygen.It uses FADH2 and NADH and utilizes the properties of cell membranes to attach an extra phosphate to and ADH molecule, creating ATP. This step also creates water and heat as waste products.
The turtles that we studied in our project use cellular respiration to turn the glucose they get from eating other organisms into ATP.
ATP: ATP is adenosine triphosphate. ATP is what cells use for energy. To make ATP they need to get glucose and then use cellular respiration to turn the glucose into usable ATP molecules. ATP creates energy so well because the bond on the third phosphate can be broken, resulting in a large release of chemical energy.
Autotroph:
A autotroph is an organism that makes its own energy. Examples of autotrophs are plants and other organisms that use photosynthesis.
Heterotroph:
A heterotroph is an organism that has to eat other organisms to obtain energy in the form of glucose.
Carrying Capacity:
The carrying capacity is the amount of organisms that an ecosystem can physically support. Populations grow quickly until they reach the carrying capacity when there are not enough resources to support them.
Ecological Pyramid:
The food chain in an ecosystem can be represented by a ecological pyramid, with each level following the 10% rule of energy transfer. The bottom level is the producer and the top level is the apex predator.
Energy Pyramid:
This pyramid shows the amount of energy in a ecosystem. It shows the 10% rule in the amount of energy in each level. The level of the producers always has more energy than the top level.
Biomass Pyramid:
This pyramid represents the total mass/living matter that each level takes up. Each level also follows the 10% rule. The total biomass of the bottom level is greatest because they get the most energy to build biomass with. The top is always lowest because they get the lowest energy to build mass with.
Number of organisms pyramid:
This pyramid is based on the number of organisms in the environment. Because of the 10% rule, about 10% less organisms can be supported at each level because of declining energy. So the producers always make up the largest group in the ecosystem because they are at the bottom of the pyramid.
Levels of Organization: Ecology organizes life into multiple levels of organization. These levels are individual, population, community, ecosystem, biome, and biosphere.
Abiotic:
Abiotic factors are the things in the environment that are not alive. They are the things like sunlight, rocks, water, and soil. Abiotic factors are important to the environment. Biotic factors adapt to them.
Biotic Factors:
Biotic factors are the living components of the environment/ecosystem. Anything that is alive is a biotic factor.
Individual:
A individual is one single organism of a species.
Population:
A population is a group of organisms of the same species.
Community:
A community is a group of different populations of organisms in one place. Communities interact together. In our project, turtles interacted with a community of other organisms like sea kelp and larger fish.
Ecosystem:
A ecosystem is a group of biotic and abiotic factors in a community. Ecosystems are living communities combined with the physical environment. The creatures in the ecosystem have adapted to the unique physical characteristics of the ecosystem. In our project, the ecosystem would be the tropical/subtropical parts of the ocean that they live in.
Biome:
A biome is a collection of multiple ecosystems that can be all grouped into one archetype. For example, the tundra biome encompasses all of the different ecosystems in the tundra. The biome is still composed of the unique animal communities that occupy a habitat. Ocean sea turtles' biome would be the Atlantic, Indian, and Pacific ocean, where their many ecosystems are located.
Biosphere:
A biosphere is all of the areas on earth that are inhabited by life. In our project the biosphere is the entire earth.
Symbiosis:
Symbiosis is organisms coexisting and interacting with each other.
Commensalism:
Commensalism is when one organism benefits and another organism is left unaffected with no benefit. One example of commensalism is when cows kick up the grass as they walk, they disturb worms that the cow egrets eat. The cow is left unaffected but the cow egret benefits.
Mutualism:
Mutualism is when both organisms involved in the interaction benefit. One example of mutualism is when a fish eats organisms on the outside of a whale. The whale get's the organisms/pests eaten off and the fish gets food.
The carbon cycle:
The carbon cycle is a important biological cycle in ecology. Carbon is slowly used and recycled in the biosphere through the process of the carbon cycle. Carbon dioxide is in the atmosphere and gets absorbed by producers for photosynthesis. The producers then emit oxygen and use the carbon to build themselves up. If the plants are not eaten, they get broken down by decomposers and the carbon is then returned to the soil. Also, animals are broken down by decomposers and their carbon is returned to the soil. The process of cellular respiration results in the exhalation of carbon dioxide so plants and animals return a significant amount of carbon to the atmosphere. If the conditions are right, carbon creates a carbon sink where the carbon stays for millions of years and eventually ends up becoming a fossil fuel. Today, humans are using fossil fuels for energy, which releases all of their carbon into the atmosphere and compromises the balance of the carbon cycle. In the ecology project, we primarily focused on the carbon cycle in the ecosystems that the turtle lived in.
Competition:
Competition is when both organisms involved in the interaction don't benefit and are damaged by the interaction. For example, two wolves competing for meat will both hurt each other in the interaction.
Biomass:
Biomass is ecological matter and energy. To have biomass an organism needs to take in kilocalories to build up energy. In the energy transfer pyramid, energy is lost as each trophic level uses up energy. Because of this, the organisms at the bottom take up the most biomass collectively. The combined mass of the producers is the greatest. Because of the loss of energy, each consecutive level has lower combined biomass. In the ocean, producers have the most collective mass, whereas elite predators like sharks have the lowest combined mass.
Disturbance of Homeostasis:
Food web/Food Chain:
The food web is a more interconnected graphical representation of the food chain. The food web accounts for multiple animals eating one another. The food chain is a linear representation of energy flow in the ecosystem. It shows each level, starting with the producers and ending with the apex predator.
Limiting Factors:
Population growth is held back by limiting factors that prevent the population from growing.
Density Dependent Factors:
Density dependent factors are factors that limit population growth that involve density. Some examples of density dependent factors are the amount of available space. Available space depends on the amount of organisms that live in the area.
Density Independent Factors:
These factors are not related to density. One example of one of these factors is natural disasters or unusual weather. They are not related to density but they still limit the growth of the population.
Biodiversity:
Biodiversity is basically the range and diversity of all the different types of species on earth. Some ecosystems have more biodiversity.
Human impact:
Humans have a large impact on the environment through our actions. Humans are causing a mass extinction because of us bring the environmental cycles out of balance. For example, fossil fuel plants emit greenhouse gases and cause climate change. This gets the carbon cycle out of balance because of the mass influx of carbon into the atmosphere that trees can not scrub quickly. In the context of sea turtles, they are greatly affected by humans. Plastic that we litter in the oceans is mistaken by sea turtles for food and they eat it and die.
First Level Consumers:
First level consumers are animals that eat producers. In the turtles' ecosystem, they are often a first level consumer.
Second level consumers:
Second level consumers eat the first level consumers, who eat the producers. Second level consumers don't get as much energy as first level consumers.
Highest level consumer/Apex Predator
The creature that is highest on the food chain is not eaten by anything. They are the apex predator. The ecosystem can not support many apex predators because of energy loss through the trophic levels. In the case of our project, the apex predator would be a shark, because they are not eaten by anything.
Animal diets:
Animals are classified based off what they eat into these groups.
Herbivore: Eats plants and other producers.
Carnivore: Eats other organisms.
Omnivore: Eats both other organisms and plants.
Detrivore:
Organisms that eat other dead organisms' remains.
Decomposer:
Decomposers are organisms like bacteria or fungi that decompose the dead remains of other organisms. Decomposers return the carbon, nitrogen and other nutrients from the remains into the soil, helping to maintain the natural cycles of the environment. In the context of the ecology project, decomposers would be the ocean bacteria and some other small creatures.
Water Cycle:
The water cycle is seen in every ecosystem on earth because of water's importance to life. Water stays in the atmosphere in the form of water vapor and condenses into clouds. Then, the water falls to earth and is absorbed into the ground and runs into different areas. Sometimes water is returned to the ocean through rivers and other transportation. Through this system, water has been recycled for millions of years. In the ocean, there is also a water cycle as water keeps evaporating and the ocean receives river water and precipitation that replaces the original supply.
Nitrogen Cycle:
The nitrogen cycle is a important biological cycle in ecosystems. Nitrogen is important for organisms to survive so the nitrogen cycle is critical to a healthy ecosystem. Nitrogen in the atmosphere is absorbed by nitrogen fixing bacteria or legume plants which gives us ammonium. Also, the nitrogen fixing bacteria form into nitrites and eventually nitrates. The nitrates are absorbed by plants, which is where most organisms then get their nitrogen by eating the plants. When living things die their bodies are broken down and the nitrogen is absorbed into the soil. Eventually the nitrogen returns to the atmosphere emissions from crops, factories or living things.
In the context of the ecology project, the sea turtles obtain their nitrogen from plants like sea grass in the ocean.
Reflection:
Overall this project went smoothly. However, our group had several high and low points during the project. One high point we had was going to do the beach cleanup and actually execute the plan that we outlined in the project. Another high point in our project was working smoothly to finish the presentation and executing that well. On the other hand, we did have some low points in the project. One low point was being unable to focus well at the start. Our group worked slowly at the start because we thought we had a lot of time. Also, a low point in our project was when we were unable to decide on our action plan. However, as a group we made it through each of these low points by organizing ourselves and following through on our action plan. In conclusion, this project posed some unique challenges and rewards.