Photosynthesis as a trade-off (exam 2)

Question 1

stomata opens

Answer 1

Potassium channels water into stomata, inflateing it. stomata open and release CO2 and water.

Question 2

stomata closes

Answer 2

potassium exits stomata and dries it out, closeing stomata. water loss decreases but CO2 concentration increases.

Question 3

Photolysis

Answer 3

use light to split water

Question 4

Pigments

Answer 4

essential to capturing light energy

Question 5

resonance

Answer 5

how energy transfers in photosystems through pigments

Question 6

Chemiosmosis

Answer 6

drives phosphorylation of ADP to ATP

Question 7

Photochemical stage photosynthesis (2)

Answer 7

-produces ATP, NADPH used to fixate carbon in stage 2
-light dependent

Question 8

Carbon reduction stage photosynthesis (2)

Answer 8

uses ATP, NADPH to reduce CO2
-light independent

Question 9

Role of water in photosynthesis

Answer 9

source of electrons and protons (and oxygen)

Question 10

Calvin-Benson Cycle (C3 photosynthesis)

Answer 10

-use RuBP and RUBISCO to create a 3 carbon chain (3-PGA) that then is turned into glucose for the plant.
-least efficient in hot dry enviroments because of Photoresperation.

Question 11

RuBISCO

Answer 11

Binds either CO2 or O2
Strong affinity for O2, esp. under high Temperature, high light, low CO2, high O2

Question 12

What happens in photorespiration?

Answer 12

Oxygenation of RUBP. produces CO2 and no sugar or atp. not good and basicly useless

Question 13

the Glycolate Cycle

Answer 13

scavenges 75% of CO2 that would be lost as glycolate in photorespiration.

Question 14

C4 Photosynthesis

Answer 14

-eliminates photoresperation by concentrated CO2, dropping it into CB cycle
-more efficinet in hot dry climates but still not the best.

Question 15

CAM Photosynthesis

Answer 15

-Time separation of CO2 capture and carbon reduction
-Reduces H2O loss
-Photoresperation eliminated, but Photosynthesis efficiency lower
-most efficient in dry hot climates.