Biology 2483A Lecture Notes - Plant Litter, Parent Material, Soil

• School: Western University
• Department: Biology
• Course: Biology 2483A
• Professor: Hugh Henry

Document Summary

Biochemistry the study of the physical, chemical and biological factors that influence the movement and transformation of elements. Understanding biogeochemistry is important in determining the availability of nutrients chemical elements required for metabolism and growth. Nutrients must be in certain forms for uptake by organisms. The rate of physical and chemical transformations determines the supply of nutrients. Nutrients enter ecosystems through the chemical breakdown of minerals in rocks or through fixation of atmospheric gases. Carbon (c) is the main component of structural compounds in plants; nitrogen (n) is largely tied up in enzymes. C:n ratios reflect biochemistry: animals have lower c:n ratios (6 for humans); plants have c:n ratios of 10 40. All organisms have similar nutrient requirements but amounts and specific nutrients needed vary. Herbivores must consume more food than carnivores to get enough nutrients such as n. All plants require a set of essential nutrients. Animals mostly get nutrients in food as large, complex molecules.