Sulfur Cycle

Question 1

is an essential element for the macromolecules of living things.

Answer 1

Sulfur

Question 2

As a part of the amino acid cysteine, it is involved in the formation of disulfide bonds within proteins, which help to determine their 3-D folding patterns, and hence their functions.

Answer 2

Sulfur

Question 3

is found in the form of sulfur dioxide (SO2)

Answer 3

Atmospheric Sulfur

Question 4

Atmospheric Sulfur enters the atmosphere in three ways

Answer 4

• decomposition of organic molecules,
• volcanic activity and geothermal vents
• burning of fossil fuels by humans.

Question 5

Sulfur dioxide from the atmosphere becomes available to terrestrial and marine ecosystems when it is dissolved in _________ as weak sulfuric acid or when it falls directly to the Earth as _________.

Answer 5

Precipitation; fallout

Question 6

True or False: Weathering of rocks also makes sulfates available to terrestrial ecosystems. Decomposition of living organisms returns sulfates to the ocean, soil and atmosphere.

Answer 6

True