Photosynthesis, the process by which green plants and some other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide and minerals into oxygen and energy-rich organic compounds. It would be impossible to overestimate the importance of photosynthesis in maintaining life on Earth. If photosynthesis ceased, there would soon be little food or other organic matter on Earth. And during cellular respiration, a molecule of glucose is gradually broken down into carbon dioxide and water. Along the way, some ATP is produced directly in reactions that transform glucose. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Much more ATP, however, is produced later in a process called oxidative phosphorylation. Biotic factors are all living organisms within an ecosystem. These can be plants, animals, fungi and any other living thing. Abiotic factors are all non-living things present in an ecosystem. Abiotic factors come in all types and can vary between different ecosystems. For example, abiotic factors present in aquatic systems can be things like water depth, pH, sunlight, turbidity (amount of cloudiness in the water), salinity (salt concentration), available nutrients ( nitrogen, phosphorus, etc.) and dissolved oxygen (quantity of oxygen dissolved in water). Abiotic variables found in terrestrial ecosystems can include things like rain, wind, temperature, altitude, soil, pollution, nutrients, pH, soil types, and sunlight. The biotic factors I depend on are cows, pigs, fruits, herbs, and vegetables. Heterotrophs cannot make their own food, so they must eat or absorb it. For this reason heterotrophs are also called consumers. Consumers include all animals and fungi and many protists and bacteria. They can consume autotrophs or other heterotrophs or organic molecules from other organisms. Heterotrophs show great diversity and can appear much more fascinating than producers. But heterotrophs are limited by our total dependence on those autotrophs that originally produced our food. If plants, algae and autotrophic bacteria disappeared from the earth, animals, fungi and other heterotrophic organisms would soon disappear too. All life requires a constant supply of energy. Only autotrophs can transform that ultimate solar source into the chemical energy of food that fuels life. Chemosynthesis, process in which carbohydrates are produced from carbon dioxide and water using chemical nutrients as an energy source, rather than sunlight used for energy in photosynthesis. Most life on earth is powered directly or indirectly by sunlight. There are, however, some groups of bacteria, called chemosynthetic autotrophs, which are not powered by the sun but by the oxidation of simple inorganic chemicals, such as sulfates or ammonia. Chemosynthetic autotrophs are a necessary part of the nitrogen cycle. Some groups of these bacteria are well adapted to the conditions that would have existed on earth billions of years ago, leading some to postulate that they are living representatives of the first life on earth. Please note: this is just a sample. Get a custom paper now from our expert writers. Get a Custom Essay This view was supported by the discovery of small ecosystems thriving in warm water (350°C/660°F) that.