Environment - Carbon Cycle

Explanation
Organic molecules are defined as molecules that contain carbon. Carbon is a unique element that has the ability to form strong covalent bonds with other carbon atoms and a wide variety of other elements. This versatility allows carbon to form the complex and diverse structures found in organic molecules. Organic molecules are the building blocks of life and are essential for the functioning of biological systems. They can range from simple molecules like methane to complex structures like proteins and DNA. By containing carbon, organic molecules have the ability to form the backbone of biological macromolecules and participate in various chemical reactions.

Explanation
Animals obtain carbon by consuming plants. Plants are the primary producers in the food chain and they undergo photosynthesis, converting sunlight, water, and carbon dioxide into glucose and oxygen. Animals then consume these plants, either directly or indirectly, to obtain the carbon they need for energy and growth. This process allows carbon to flow through the ecosystem, with plants acting as a source of carbon for animals.

Explanation
Respiration is the process in which organisms, including plants and animals, release carbon dioxide back into the environment. During respiration, living organisms take in oxygen and break down glucose molecules to produce energy, water, and carbon dioxide. This carbon dioxide is then released into the atmosphere, where it can be taken up by plants during photosynthesis. Respiration plays a crucial role in the carbon cycle, ensuring that carbon is continuously cycled between living organisms and the environment.

Explanation
During decomposition, substances undergo a chemical reaction where they are broken down into simpler molecular substances. This process involves the breaking of chemical bonds within the original substance, resulting in the formation of new compounds or elements. Decomposition reactions can be caused by various factors such as heat, light, or the presence of catalysts. This process is essential in nature as it helps in the recycling of nutrients and the breakdown of organic matter.

Explanation
During combustion, substances undergo a chemical reaction in the presence of oxygen, resulting in the release of heat and light. This process is commonly known as burning. The substances involved in combustion are typically oxidized, breaking down into simpler molecules or elements. This reaction releases energy in the form of heat and often produces flames. Combustion is a fundamental process in many natural and human activities, such as burning fossil fuels for energy production or the metabolism of food in living organisms.