Interrelationship between photosynthesis and respiration

Question 1

explain photosynthesis

Answer 1

6CO2 + 6H20 -> C6H12O6 + 6O2
carbon dioxide + water -> glucose + oxygen
-need energy and electrons so it is endothermic and a reduction reaction
-carbon fixation

Question 2

what is photosynthesis used for

Answer 2

carbon fixation for :
-respiration (for energy)
-starch (store)
-cellulose cell wall
-lipid
-protein
-other organic material

Question 3

what are autotrophs and heterotrophs

Answer 3

autotrophs= producer- use energy from photons of light to synthesis large organic molecules from simple inorganic molecules CO2 and H2O e.g plants algae

heterotrophs= consumers- obtain energy from digesting complex organic molecules of food to smaller molecules for use as respiratory substrates e.g fungi, animals, many protoctists

Question 4

what is the importance of photosynthesis

Answer 4

-complex molecules synthesised during photosynthesis are a source of chemical potential energy
-during respiration these molecules are oxidised and chemical energy is released (exothermic) for cellular work

Question 5

what is the role of photosynthesis in cycling carbon and oxygen

Answer 5

-carbon fixation during photosynthesis helps regulate the concentration of carbon dioxide in the atmosphere and oceans
-also adds oxygen to the atmosphere

Question 6

what is the compensation point

Answer 6

when (at certain light intensity) rate of photosynthesis is equal to rate of respiration and so
amount of CO2 used = amount of CO2 produced
amount of O2 produced = amount of O2 used

Question 7

explain what below and above compensation point means

Answer 7

below= respiration rate is bigger than photosynthesis rate

above = photosynthesis rate is higher than respiration rate

Question 8

how do plants in the sun differ to those in the shade

Answer 8

sun= higher compensation point as they photosynthesise at higher light intensity