Bio227 Marine Plankton - Plankton Multi-Nutrient Physiology

Front 1

Nutrients needed.

Back 1

Nitrogen, phosphorus, silicon, iron, vitamins, light.

Front 2

Phosphorus

Back 2

Used for structure; phospholipids in membrane; linkers in DNA.

Front 3

Sources of phosphorus

Back 3

Inorganic P - as limiting as N in freshwater; when dissolved, usually 0-2 um

Organic P - degraded to phosphate by extracellular phosphatase

- Alkaline in marine spp.

- Acidic in freshwater spp.

Front 4

Is nitrogen accumulated as DIN or DON?

Back 4

DON, except in low concentrations within in vacuoles, most are organics (amino acids, nucleic acids, proteins)

Front 5

How is P accumulated?

Back 5

Polyphosphate (inorganic P) in high concentrations.

Front 6

How much P is needed in relation to N?

Back 6

1/10

Front 7

Which is more limiting, N or P?

Back 7

P

Front 8

Define 'quota'

Back 8

The amount of material per unit of cell or carbon

Front 9

What is growth rate related to?

Back 9

Quota of limiting nutrients; N, P and vitamins

Front 10

How can quota behave?

Back 10

- Range from Qmax to Qmin

- Exceed Qmax up to Qabs, but them not affect K (therefore is not limiting)

Front 11

P is highly concentrated, involved in energetics, therefore...

Back 11

Rapid recycling can compensate for low P concentration.

Front 12

What do the quota curves for P and N look like?

Back 12

P has a steep start and plateau, it reaches Qmax quickly, whereas N has a more shallow curve.

Front 13

Is growth a function of internal or external nutrients?

Back 13

Internal. If there is an absence of external nutrients, growth continues until Q = Qmin

Front 14

What is KQ?

Back 14

Growth rate quota

Front 15

What does KQ describe?

Back 15

The curve shape, irrespective of the range of Qmin, Qmax and Qabs.

Front 16

What is silicon (Si) used for in diatoms?

Back 16

- Frustules

- Cell division

Front 17

Previously assimilated Si can't be redistributed within the cells, therefore...

Back 17

Quota relationship does not apply.

Front 18

What happens under non-Si limitation?

Back 18

Cell cycle is prolonged, more Si is deposited, therefore Si:C increases.

Front 19

What is silicate used for in diatoms?

Back 19

Cell walls

- Rigid

- Overlapping valves

- These move apart during growth

- New valves made inside existing ones

Front 20

How and where do diatoms have an advantage?

Back 20

In high nutrient, upwelling waters; kept from sinking; Si supply.

Front 21

What [compound] is [Si] similar to?

Back 21

NO3-

Front 22

What happens during the G1 phase?

Back 22

Cell expansion

Front 23

What happens during the G2 phase?

Back 23

Cells prepare for division

Front 24

What happens during the M phase?

Back 24

Mitosis and cell division

Front 25

What happens in Si limited cells?

Back 25

Less Si per cell

- Spines (SSi) disappear

- Girdle (GSi) gets larger but cell cannot divide

Front 26

What happens in N limited cells?

Back 26

- More spines

- Retain more Si per cell