What is the term for each step in the transfer or energy and matter within a living organism? Cellular respiration, Photosynthesis, First trophic level, Carbon cycle, and ATP production are all terms related to energy. In a nutshell, these terms describe the process by which photosynthesis takes place in plants. Without sunlight, plants and animals cannot produce energy, and producers in some ecosystems do not require sunlight to grow or survive.


Photosynthesis is the process by which plants convert light energy into stored chemical energy. Light energy is transferred from the Sun to the plant through a process called photosynthesis. The plant uses the energy to construct sugar molecules. Water and carbon dioxide are combined in the presence of light to create glucose molecules. Carbon dioxide is released as a byproduct, but oxygen is incorporated into the sugar molecules. This process is an important one for plants and humans, as they can use this stored energy to grow and reproduce.

When light enters the plant, chlorophyll molecules attached to granular stacks absorb some of the light. The chlorophyll molecules absorb some of the light, and some of it is converted into chemical energy. Then, phosphate is added to a molecule and the energy is transformed into ATP. ATP then provides energy for other photosynthetic reactions.

Cellular respiration

The process of cellular respiration is a series of chemical reactions in which energy is transferred from one form to another within a cell. This process is called chemiosmosis, and it is carried out at the cell membrane of mitochondrial nuclei. The process releases high-energy electrons from NADH and FADH2, which then travel along electron-transport chains on the inner membrane of the mitochondrion. This process involves transferring electrons and hydrogen ions, two of which are used as starting points in the ion transfer.

The first step of cellular respiration is glycolysis, which breaks down glucose molecules into pyruvate and ATP. Then, the Krebs cycle takes place, which releases high-energy electrons from FADH2 and NADH2. In the third step, the oxygen acts as a final proton acceptor, forming water. The ETC is depicted in Figure 4.10.8.

First trophic level

The efficiency of a trophic level in transferring energy and matter within an ecosystem is defined as the ratio of energy produced by that trophic level to the amount consumed by organisms in the next trophic level. An organism’s assimilation efficiency, or the ratio of energy produced per unit area, accounts for the amount of energy ingested and lost in respiration, excretion, and waste. This is important because the amount of biomass generated per organism and time period varies based on the trophic level. As a result, energy is available in different ecosystems, and the number of organisms in each trophic level depends on the human population.

The trophic level of an ecosystem can be described using a food web or food chain model. The first trophic level is made up of algae and plants, which are primary producers. The second level is made up of detritus, which is the source of nutrients and energy for all organisms. The highest trophic level, which includes fish, is the apex consumer and includes Chinook salmon. In contrast, the food web diagrams represent interactions between these different trophic levels and their relationship to the energy source.

Carbon cycle

The Earth’s carbon cycle occurs in two parts: the soil and the atmosphere. Organic matter decays slowly, and carbon is stored in the soil as inorganic carbon. Fossil fuels are formed from anaerobically decomposing plant matter and take millions of years to form. As carbon is a non-renewable resource, it can only be slowly replaced by biogeochemical processes. Volcanic eruptions and geothermal systems also release carbon into the atmosphere.

Human activity has perturbed the carbon cycle, with changes to land use over the last 130 years. While these changes are small compared to the natural fluxes, they are changing the net carbon dioxide concentrations of the atmosphere. In fact, carbon dioxide concentrations are rising at a rate of 3.2 gigatonnes per year due to anthropogenic activity. However, the effects of the human carbon emissions on the planet’s climate are largely unmeasurable, even if they are small in magnitude.

Food web

The food chain has multiple trophic levels and each of them has a distinct role. The primary consumers and the secondary producers feed on each other. The second and third-order consumers consume the biomass of the former. Each step of the food chain consumes the energy and releases it as heat. Those who eat fish, plants, and bacteria use this energy to stay warm.

The primary source of energy for many ecosystems is the sun. It is used to make organic matter by producers, using energy from the sun, carbon dioxide, and water. Almost every food web begins with the sun. The energy flows from the sun through plants to animals and then back to plants. Once energy flows through the food chain, it will continue to flow up and down the food chain.