2.5.1 Photosynthesis Flashcards
What is Photosynthesis
Photosynthesis is an endothermic reaction in which energy from sunlight is transferred to the chloroplasts in green plants
What is an endothermic reaction?
A chemical reaction that takes energy from the surroundings; the products are higher in energy than the reactants
What do plants do with the energy
Green plants use this energy to make the carbohydrate glucose from the raw materials carbon dioxide and water
At the same time, oxygen is made and released as a waste product
Photosynthesis can be defined as the process by which plants, do what?
the process by which plants manufacture carbohydrates from raw materials using energy from light
Why are plants Autotrophs
they can make complex molecules (glucose) from simple molecules (carbon dioxide and water)
Why are plants Producers
they can make their own food and so are the first organism at the start of all food chains
Plants use the glucose they make for what?
as a source of energy in respiration
What else can they use the glucose for?
Produce starch for storage
Synthesise lipids for an energy source in seeds
To form cellulose to make cell walls
Produce amino acids (used to make proteins) when combined with nitrogen and other mineral ions absorbed by roots
(Exam Tip) If asked for the raw materials required for photosynthesis, what is the answer?
carbon dioxide and water. Although required for the reaction to take place, light energy is not a substance and therefore cannot be a raw material.
What is the word equation for photosynthesis
Carbon Dioxide + Water -> Glucose + Oxygen
What is chemical equation for photosynthesis
6 CO2 (Carbon Dioxide) + H20 (water) –> C6 H12 O6(Glucose)+ 6O2 (Oxygen)
(Exam Tip) The photosynthesis equation is the exact reverse of the aerobic respiration equation, what is the anerobic respiration equation?
C6 H12 O6 + 6O2 —> 6 CO2 + H20
