Unit 10: Biological Molecules and
Metabolic Pathways
C: Explore the factors that can affect the pathways and the rate of photosynthesis in plants
Pearson BTEC Level 3 National Extended Diploma in Applied Science
Student: Nikki C. Moslares
,The processes of photosynthesis:
Photosynthesis is a biochemical reaction by “photosynthetic autotrophs” where they convert solar energy to potential energy.
Photosynthesis is commonly performed by plants, algae and other types of bacteria, they obtain energy from sunlight to produce oxygen
and chemical energy that is kept in glucose.
Within the process of photosynthesis, plants will acquire carbon dioxide (CO2) from air and water (H2O) from soil. Inside the plant cell,
water will oxidise (lose electrons), then the carbon dioxide gets reduced (gains electrons). Water will then become carbon dioxide and
carbon dioxide into glucose. Energy is then stored in glucose and the plant releases oxygen to the environment. (National Geographic,
Photosynthesis)
The chemical formula for Photosynthesis
6 CO 2+ 6 H 2 O=C 6 H 12 O6 +6 O2
carbon dioxide + water = glucose + oxygen
The part of the plant where photosynthesis happens is in the chloroplasts (this consist of a primary pigment known as Chlorophyll).
Chloroplasts are placed within a double membrane with a third membrane called a thylakoid membrane. Chlorophyll is found inside the
thylakoid membrane. In between the thylakoid and chloroplast, stroma can be seen. (see in fig.1)
fig. 1 by nature.com
Nature news. Nature Publishing Group. Available at: https://www.nature.com/scitable/topicpage/photosynthetic-cells-14025371/#:~:text=In%20plants%2C
%20photosynthesis%20takes%20place,long%20folds%20within%20the%20organelle. (Accessed: March 16, 2023).
, Light–dependent reactions vs Light-independent reactions
There are two different types of photosynthesis reactions that help in producing energy (ATP) to the plant or organism:
Light-dependent Reaction: Light independent reaction (Calvin Cycle):
Light-dependent reactions utilises photosynthetic pigments such as a
chloroplast (has chlorophyll that aids in photosynthesis), this will
convert light energy into chemical energy like ATP and NADPH. Light independent reaction is collectively called as ‘’Calvin
cycle’’. This reaction is the final stage of photosynthesis which
Step 1: Excitation of Photosystems by Light energy transpires in the stroma. The ATP and NADP released from the
o Photosystems are groups of chloroplasts enclosed inside a light-dependent reaction will be used in the production of
thylakoid membrane. glucose. It does not require ‘’light energy’’ but it does not mean
that the reaction happens in the dark. Light independent reaction
o The systems are classified depending on their ‘’maximal
will need the produced ATP and NADPH from light-dependent
absorption wavelengths’’ (PS 1 = 700nm, PS 2 = 680nm) reaction to operate.
o When the photosystems absorb light energy, delocalised
electrons in the pigment gets energised or excited –
Metabolic Pathways
C: Explore the factors that can affect the pathways and the rate of photosynthesis in plants
Pearson BTEC Level 3 National Extended Diploma in Applied Science
Student: Nikki C. Moslares
,The processes of photosynthesis:
Photosynthesis is a biochemical reaction by “photosynthetic autotrophs” where they convert solar energy to potential energy.
Photosynthesis is commonly performed by plants, algae and other types of bacteria, they obtain energy from sunlight to produce oxygen
and chemical energy that is kept in glucose.
Within the process of photosynthesis, plants will acquire carbon dioxide (CO2) from air and water (H2O) from soil. Inside the plant cell,
water will oxidise (lose electrons), then the carbon dioxide gets reduced (gains electrons). Water will then become carbon dioxide and
carbon dioxide into glucose. Energy is then stored in glucose and the plant releases oxygen to the environment. (National Geographic,
Photosynthesis)
The chemical formula for Photosynthesis
6 CO 2+ 6 H 2 O=C 6 H 12 O6 +6 O2
carbon dioxide + water = glucose + oxygen
The part of the plant where photosynthesis happens is in the chloroplasts (this consist of a primary pigment known as Chlorophyll).
Chloroplasts are placed within a double membrane with a third membrane called a thylakoid membrane. Chlorophyll is found inside the
thylakoid membrane. In between the thylakoid and chloroplast, stroma can be seen. (see in fig.1)
fig. 1 by nature.com
Nature news. Nature Publishing Group. Available at: https://www.nature.com/scitable/topicpage/photosynthetic-cells-14025371/#:~:text=In%20plants%2C
%20photosynthesis%20takes%20place,long%20folds%20within%20the%20organelle. (Accessed: March 16, 2023).
, Light–dependent reactions vs Light-independent reactions
There are two different types of photosynthesis reactions that help in producing energy (ATP) to the plant or organism:
Light-dependent Reaction: Light independent reaction (Calvin Cycle):
Light-dependent reactions utilises photosynthetic pigments such as a
chloroplast (has chlorophyll that aids in photosynthesis), this will
convert light energy into chemical energy like ATP and NADPH. Light independent reaction is collectively called as ‘’Calvin
cycle’’. This reaction is the final stage of photosynthesis which
Step 1: Excitation of Photosystems by Light energy transpires in the stroma. The ATP and NADP released from the
o Photosystems are groups of chloroplasts enclosed inside a light-dependent reaction will be used in the production of
thylakoid membrane. glucose. It does not require ‘’light energy’’ but it does not mean
that the reaction happens in the dark. Light independent reaction
o The systems are classified depending on their ‘’maximal
will need the produced ATP and NADPH from light-dependent
absorption wavelengths’’ (PS 1 = 700nm, PS 2 = 680nm) reaction to operate.
o When the photosystems absorb light energy, delocalised
electrons in the pigment gets energised or excited –
