Nutrient Cycling in the Serengeti
INTRODUCTION
In the card activity, you explored some ways that Serengeti plants get the nutrients they need. In this handout,
you will learn more about the roles of nutrients and reflect on processes and organisms in the card activity. You
will then take a closer look at how one nutrient, carbon, moves through an ecosystem.
PART 1: Nutrients and Their Roles
All organisms need certain compounds from the environment, called nutrients, to survive. Nutrients are used to
build biological molecules needed for life, such as carbohydrates and proteins. They also help support cellular
functions and life processes.
Depending on various environmental factors, nutrients can come in multiple forms. For simplicity’s sake,
scientists often refer to a nutrient using the essential element that is part of its compound. For example, the
nutrient referred to as carbon (C) is often in the form of the compound carbon dioxide (CO
2
).
1. The “How Savanna Plants Get Nutrients” handout from the card activity describes the nutrients carbon,
phosphorus, and nitrogen and some of their common forms.
a. Name one compound that is a form of the nutrient phosphorus.
b. Name two compounds that are forms of the nutrient nitrogen.
Read more about how plants use carbon, nitrogen, and phosphorus below. Use this information to answer the
question that follows.
• Carbon is the backbone of all organic molecules. It is part of all proteins, carbohydrates, fats, and nucleic
acids, as well as many other important molecules that plants use for metabolism, growth, cell membranes,
and reproduction.
• Nitrogen is used to build amino acids, the building blocks of proteins, and nucleic acids, such as DNA and
RNA. Nitrogen is also part of the chlorophyll molecule, which is needed for photosynthesis.
• Phosphorus is important for the development of healthy root systems and seeds. Plants also need
phosphorus for photosynthesis, cellular respiration, cell membranes, and other cellular processes.
2. List three biological functions or processes that these nutrients are needed for in plants.
3. Which of the following statements best describes where plants get these nutrients? (Hint: Review your
“How Savanna Plants Get Nutrients” handout.)
a. Carbon from the soil, nitrogen and phosphorus from the air.
b. Carbon, nitrogen, and phosphorus from the soil.
c. Carbon, nitrogen, and phosphorus from the air.
d. Carbon from the air, nitrogen and phosphorus from the soil.
