Question

1. plants and animals are part of all of the nutrient cycles through the foods they eat and what eats them (food chains and food webs). name the four classes of organic compounds (containing carbon) and explain how the carbon cycle and nitrogen cycle contribute to the usable supplies of these macromolecules.
2. metabolism is the collective term used to describe all the chemical reactions taking place inside living organisms. why is water so important for metabolic reactions?
3. some molecules that are covalently bonded do not have a difference in charge across the molecule. these molecules are referred to as nonpolar. what arrangement of electrons would result in a nonpolar molecule?

Explanation:

42.

The four classes of organic compounds are carbohydrates, lipids, proteins, and nucleic acids. In the carbon - cycle, plants take in carbon dioxide during photosynthesis and incorporate carbon into organic compounds. Animals eat plants and other animals, and when they respire, they release carbon dioxide back into the atmosphere. Decomposers break down dead organisms, returning carbon to the soil or atmosphere. In the nitrogen - cycle, nitrogen - fixing bacteria convert atmospheric nitrogen into a form usable by plants. Plants take up this nitrogen and incorporate it into proteins and nucleic acids. Animals eat plants and other animals, obtaining nitrogen. When organisms die, decomposers break down their bodies, releasing nitrogen back into the soil or atmosphere.

Water is important for metabolic reactions because it is a universal solvent, allowing many substances to dissolve and participate in reactions. It also participates in hydrolysis and dehydration synthesis reactions. Additionally, water helps in temperature regulation and lubrication within organisms.

In non - polar molecules, electrons are symmetrically arranged around the molecule. This even distribution of electrons results in no net charge separation across the molecule, making it non - polar.

Answer:

The four classes of organic compounds are carbohydrates, lipids, proteins, and nucleic acids. In the carbon - cycle, plants use carbon dioxide in photosynthesis, animals consume plants/other animals and respire carbon dioxide, and decomposers break down dead matter. In the nitrogen - cycle, nitrogen - fixing bacteria convert atmospheric nitrogen, plants take it up, animals consume plants/other animals, and decomposers release nitrogen from dead organisms.

43.