photosynthesis QP1

Question 1

What are ways in which grana are adapted to its function

Answer 1

-large sa for electron transport chain
-contain photosystems
-contain electron carriers/ ATP synthase
-large surface area for light absorption/ light dependent reaction/ light dependent stage/ electron transport

Question 2

why is temperature a limiting factor to photosynthesis

Answer 2

Calvin cycle/light dependent reaction involves enzymes/ relies on kinetic energy of molecules

Question 3

why is CO2 conc. a limiting factor

Answer 3

CO2 becomes limiting as its required for the Calvin cycle/ light independent reaction/ formation of carbon cycle compound, reaction with RuBP/ fixation by RuBisCo

Question 4

outline the ways in which heterotrophic organisms are dependent on plants

Answer 4

-plants produce organic molecules during photosynthesis/ calvin cycle/ light independent stage
-heterotrophs will feed off plants to gain organic molecules
-these organic molecules will be broken down in respiration

Question 5

how will the structure of leaves in the shade be like

Answer 5

-larger sa
-more/larger chloroplasts/ palisade mesophyll
-more grana/ thylakoids
-more photosystems

Question 6

what are the advantage of plants having a range of accessory pigments in photosystems

Answer 6

able to absorb a range of/ more wavelengths of light

Question 7

define autotroph

Answer 7

able to make its won organic molecules from inorganic molecules

Question 8

define heterotroph

Answer 8

relies on organic molecules that have been made by an other organism. -feeds on and digests

Question 9

what is the use of fats stored in a chloroplast

Answer 9

-for membrane formation
-phospholipid/ cholesterol/ glycolipid for membrane

Question 10

describe how light is harvested in the chloroplast membrane

Answer 10

• primary and secondary pigments form a photosystem
  -photon absorbed by pigment molecule
• electron is excited and moved to a higher energy level and returned to pigment
  -photon passed to reaction center/ chlorophyll A
  -a range of accessory pigments allow range of wavelengths to be absorbed
  -energy/photon passed from one pigment to another

Question 11

explain what would happen to photosynthesis if ps2 wasn’t working

Answer 11

• non cyclic photophosophorylation would be prevented
  -no electrons available in etc to form reduced NADP
  -no/less ATP and no reduced NADP available for clavin cycle/light independent reaction

Question 12

what factors limit rate of photosynthesis

Answer 12

light intensity, temperature, CO2 conc

Question 13

what would happen if photosystem one stopped happening

Answer 13

-prevents photophosphorylation
-cyclic and non-cyclic
-no/less ATP/ reduced NADP for light independent reaction/calvin cycle
-no normal substrate for respiration