Topic 5A- Photosynthesis and Respiration Flashcards
What is the overall reaction for photosynthesis?
water + carbon dioxide -> glucose + oxygen
what are the two stages of photosynthesis?
light dependent stage
light independent stage
List three things that the rate of photosynthesis is affected by
- carbon dioxide concentration
- light intensity
- temperature
What is the site of photosynthesis?
chloroplasts
How are chloroplasts adapted to photosynthesis?
- stack of thylakoid membranes called grana (large SA)
- network of proteins in the grana hold the chlorophyll in a very specific manner (to absorb the max amount of light)
- the granal membrane has a selectively permeable membrane to establish a proton gradient
- chloroplasts contain DNA and ribosomes (allowing them to synthesise proteins needed in the light dependent reaction)
What is photolysis?
the splitting of water with light
What is photoionisation?
when light hits the chlorophyll molecules in PSII causing the electrons to become excited
What does the charge separation from photoionisation cause?
the process of photolysis
What is produced when water is split?
1 molecule of oxygen
4 protons (H+)
4 electrons
Where is the LDR located?
Thylakoid membrane
What is the purpose of the LDR?
Converts light energy to ATP and NADPH for Calvin cycle
Name the four stages of the LDR
- Photoionisation of chlorophyll
- Photolysis of water
- ATP synthesis
- Formation of NADPH
What are the products of the LDR?
ATP
NADPH
O2 (waste)
What occurs in the photoionisation of chlorophyll?
Light energy is absorbed, exciting electrons
Excited electrons leave chlorophyll and transferred down ETC
What occurs in the photolysis of water?
Light energy splits water
O2 released as waste
What happens in ATP synthesis in the LDR?
Electrons travel down ETC releasing energy to transport H+ ions out in the thylakoid space
H+ diffuse in stroma driving ATP synthase
What happens in the formation of NADPH in the LDR?
Electrons from ETC reduce NADP, combining it with H+ ions from photolysis
Where is the Calvin Cycle located?
Stroma
What are the products of the Calvin cycle?
Glucose
Regenerated RuBP
ATP and Pi
NADP
What are two products form the Calvin cycle that are needed for the LDR?
ATP and Pi
NADPH
