Mod 4 Phosphorus Cycle

Question 1

Why is P important for organisms

Answer 1

Responsible for ATP, DNA, RNA, and the phospholipids that form cell membranes

Question 2

In freshwater P…

Answer 2

limits primary production

Question 3

Main source of P for the oceans is

Answer 3

runoff from rivers

Question 4

T or F?

The phosphorous cycle occurs in the atmosphere

Answer 4

False

Question 5

Total phosphorus (TP)

Answer 5

The concentration of total phosphorus (TP) is obtained by a strong acid digest of the sample which makes all the different forms of phosphorus in the sample available as dissolved inorganic phosphorus (DIP), which can then be measured colorimetrically.

Question 6

Total particulate phosphorus (TPP)

Answer 6

Total particulate phosphorus is separated from TP by filtering the sample

Question 7

Total dissolved phosphorus (TDP).

Answer 7

Total dissolved phosphorus (TDP) is the material that passes through the filter. This can be dissolved inorganic phosphorus (DIP) or dissolved organic phosphorus (DOP).

Question 8

Dissolved Inorganic Phosphorus (DIP).

Answer 8

Dissolved inorganic phosphorus (DIP) is the most commonly measured form of phosphorus. You will see it refereed to by various names including:

• PO43-
• Dissolved reactive phosphorus
• Phosphate
• Orthophosphate
• Filterable reactive phosphorus

Question 9

Dissolved Organic Phosphorus (DOP).

Answer 9

Dissolved organic phosphorus consists of a number different compounds including:

• DNA and RNA (contain and transfer genetic information)
• ATP (control and transfer of energy)
• Phospholipids (structure)