M A ST E R 1 .1
NAME
Essential Elements
DATE
AN ESSENTIAL ELEMENT
1. is required for a plant to complete its life cycle;
2.
cannot be replaced by another element;
3.
is directly involved in the plant’s metabolism; and
4. is required by many different plants.
Adapted from Arnon, D., & Stout, P. (1939, July). The essentiality of certain elements in minute quantity for plants with special reference to copper.
Plant Physiology, 14(3), 599–602.
MASTER 1.2
NAME
THE PERIODIC TABLE
DATE
MASTER 1.3
Essential Elements
FOR PLANTS
NAME
DATE
MASTER 1.4
Essential Elements
FOR HUMANS
NAME
DATE
MASTER 1.5
SOURCES OF
Essential Elements
ESSENTIAL NUTRIENT
Boron (B)
Calcium (Ca)
Carbon (C)
Chlorine (Cl)
Copper (Cu)
Hydrogen (H)
Iron (Fe)
Magnesium (Mg)
Manganese (Mn)
Molybdenum (Mo)
Nickel (Ni)
Nitrogen (N)
Oxygen (O)
Phosphorous (P)
Potassium (K)
Sulfur (S)
Zinc (Zn)
AIR
SOURCE WATER
NAME
DATE
SOIL
MASTER 1.6
NAME
USING NITROGEN
DATE
For many plants, the availability of nitrogen limits their growth. This fact is surprising since the air is nearly
80 percent nitrogen. However, neither plants nor animals can use the nitrogen gas (N2 ) in the air. First, it must
be fixed, or combined with other elements combined with other elements, such as hydrogen or oxygen, before
plants can use it. Lightning strikes are one way that nitrogen can be fixed. In this case, nitrogen gas combines
with oxygen to form NO3 -. Free-living bacteria in the soil convert the largest amounts of atmospheric nitrogen
by combining it with hydrogen. When combined with oxygen or hydrogen, plants can take in and use the
nitrogen in these forms as an essential element. Industrial processes also fix nitrogen to produce nitrogenbased fertilizers. Animals take in the nitrogen they need by eating plants. When animals expel waste, or when
plants or animals die and decompose, the nitrogen returns to the soil. Other bacteria in the soil convert the
nitrogen back to nitrogen gas (N2 ) which then returns to the atmosphere. This completes the nitrogen cycle.
Questions
1. L
ook at the graphic of the nitrogen cycle. What do you think is responsible for converting most of
the nitrogen used by plants into a usable form?
2. P
lants of the legume family, such as peas and beans, live in a symbiotic relationship with bacteria
that live in their roots. The bacteria use sugars from the plants to produce energy. In return, the
bacteria take nitrogen from the air and convert it to a form that the plants can use. Why is this
ability of legumes to use nitrogen this way important to farmers?
MASTER 1.7
NAME
FOOD LABEL
DATE
1. List any essential elements listed on the food label.
2. Most ingredients on food labels are chemical compounds composed of different elements. Select three
ingredients on the food label and write them in the first column of the chart below.
3. Use the Internet to find the chemical formula for each of the three ingredients. Write the formula for each
ingredient in the second column.
4. For each ingredient, list the essential elements that are part of its chemical structure.
INGREDIENT FROM
FOOD LABEL
CHEMICAL
FORMULA
Essential elements contained
in the ingredient