Organisms need energy to survive. Some of them can absorb energy from the sunlight and use it to produce sugar and other organic compounds. You certainly know this process under the name of “photosynthesis”, used by plants and some bacteria or blue-green algae. Carbon dioxide nCO2 and water nH20 under sunlight and in presence of chlorophyll product glucose (CHOH)n and oxygen nO2.
In the photosynthesis there are two reactions:
The first is the “light reactions”, energy of light is conserved as high energy involving ATP and NADPH. The proteins and pigments responsible for the photosynthetic light reaction are associated with thylakoid (grana) membranes.
The second is called Calvin cycle, and on the contrary of the first is the “dark reactions pathway”. Enzymes and intermediates of the cycle are located in the chloroplast stroma.
Now make this little Quiz (A to J), to check your knowledges. After you’ll find the good answers at the end of the quiz.
A) Which of the following are capable of photosynthesis
- Plants, and animals
- plants, some bacteria, some protists, some algae
- Plants and some protists only
B) In plants, photosynthesis mainly occurs in the:
C) Plants use carbon dioxide, water and sunlight to produce water, glucose and …..
- Carbone dioxide
D) This green pigment captures the sun’s energy in photosynthesis
E) Light reactions mostly occur in which part of the chloroplast?
F) Dark reactions occur in which part of the chloroplast?
- Outer membrane
G) True or False, Dark reactions in most plants occur during the day:
H) In Calvin Cycle, Carbon dioxid is converted to:
I) Both, ATP and NADPH are pro ducted in the ……………………………. of photosynthesis
- Light reaction phases
- Dark reaction phases
J) Which is the chemical equation for photosynthesis in plants?
- C6H12O6 + 6O2 + ATP —> 6CO2 + 6H20
- 6CO2 + 12 H20 + light —> C6H12O6 + 6O2 + 6H20
- C6H12O6 + 6O2 —> 6CO2 + 6H20 + Energy
Correction: A2, B1, C1, D1, E3, F2, G1, H2, I1, J2.