Phosphorus

Question 1

What does kinase mean?

Answer 1

an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule

Question 2

What is an organic compound?

Answer 2

Always contain carbon

Question 3

What is an inorganic compound?

Answer 3

Does not contain carbon

Question 4

What does assimilation mean?

Answer 4

Uptake by living organisms into its biomass (basically take into its body)

Question 5

What does mineralization mean?

Answer 5

Release of the inorganic form?

Question 6

What form does P usually exist in and how does it affect its movement?

Answer 6

Most P exists in a solid form, and enters into active cycling through weathering

Question 7

What is mechanical weathering?

Answer 7

“breaking something into smaller pieces”. ie wind mechanically weathers rocks into smaller pieces

Question 8

What is chemical weathering?

Answer 8

Change in the chemical structure of the material. accomplished by acids and/or oxidation

Question 9

What is weathering rate impacted by?

Answer 9

temperature/moisture
location/climate/acidity
biota/living things accelerating weathering

Question 10

What is the relationship between mechanical weathering and chemical weathering?

Answer 10

The more mechanical weathering, the more chemical weathering b/c mechanical weathering increases the surface area

Question 11

What does it mean for phosphorus to be occluded?

Answer 11

The phosphorus is half onto the organic matter through charge attraction, and this phosphorus is free to enter/leave the soil solution. But, Fe and Al make sort of a shell around the phosphorus so it cannot leave.
Occluded means its deposited onto something and it cannot leave

Question 12

What is chelation?

Answer 12

a chemical compound that binds tightly to metal ions. able to complex with metal, making the metal more soluble

Question 13

Much more P is moved in _____ form than in ____ form

Answer 13

particulate, dissolved

Question 14

How is P so efficiently recycled in the ocean?

Answer 14

-fewer losses to Adsorption
-there is preferential uptake by biota
-Fe is otherwise occupied

Question 15

Why is the residence time of inorganic phosphorus much longer in the deep ocean than it is in the surface ocean?

Answer 15

Only certain biota are able to adsorb the inorganic phosphorus

Question 16

What is the halocline?

Answer 16

Halocline is the stratification of ocean water by salt level difference in ocean. the higher [salt], the denser the water

Question 17

What are some contributors to the variation in ocean salinity?

Answer 17

evaporation : h2o leaves behind salt therefore increasing [salt]
precipitation : rain dilutes ocean water therefore decreasing [salt]
freezing/melting : freezing increases [salt], melting decreases [salt]

Question 18

What is the thermocline?

Answer 18

The transition layer between the warmer mixed water at the surface and the cooler deep water below

Question 19

What is thermocline stratification?

Answer 19

Deep ocean water currents that are being circulated by differences in water density

Question 20

What is upwelling?

Answer 20

Movement of cold, deep, often nutrient rich water to the surface

Question 21

What is downwelling?

Answer 21

Occurs when surface water becomes more dense and sinks to the bottom. Downwelling occurs when sucrose waters converge, pushing the surface water down

Question 22

Describe the internal cycling of P within the oceans

Answer 22

Active P in the deep sea remains for an avg of 500 years until it is physically upwelled to the surface of the ocean where it blooms; available to be reacted with

Question 23

What does oligotrophic mean?

Answer 23

clear water with little organic matter/sediment and minimum biological activity. few sources of nutriton

Question 24

what does eutrophic mean?

Answer 24

rooted plant growth is abundant along the shore and in lake and algal blooms. water clarity os poor. if deep enough to stratify, bottom water is devoid of water. lots of nutrition available

Question 25

Why is oxygen depleted below the thermocline?

Answer 25

this is b/c waters is off from plant photosynthesis and the atmosphere, and oxygen is consumed by bacteria that use oxygen as they decompose organic matter at the bottom of the lake

Epilimnion
_____________
Thermocline
_____________
Hypolimnion

Question 26

How does Fe affect P availability in deep ocean? What happens when o2 is available again?

Answer 26

When there is low quantity of o2 at the bottom layer, Fe moves to the reduced form (Fe3+ to Fe2+). Reduced form is more soluble in water therefore it replaces P and P goes into sediments. Basically, Fe2+ reduces P availability.
When o2 is available again, P becomes available again in water.

Question 27

What is the positive feedback with eutrophication?

Answer 27

+ve feedback happens w/ eutrophication; chain of events occur to reinforce the cycle and amplify it. Eutrophication cause hypolimnion to become available