Biology 2483A Lecture Notes - Lecture 21: Cation-Exchange Capacity, Plant Litter, Soil

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

Document Summary

Biochemistry: is 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. All organisms have similar nutrient requirements but amounts and specific nutrients needed vary. Carbon is the main component of structural compounds in plants, nitrogen is largely tied up in enzymes. C:n ratios reflect biochemistry: animals have lower c:n ratios (6 for humans); plants have c:n rations of 10-40. Herbivores must consume more food than carnivores to get enough nutrients such as n. All plants require a set of essential nutrients. Some c4 and cam plants require sodium. (all animals require it) Some plants that host n-fixing bacteria require cobalt.