Photosynthesis-Aaahhhh!
By Ashiqur Rahman Adit
“Plants produce energy through the process of photosynthesis”-maybe I heard this before I was born! Photosynthesis is a long word, and to some people it’s frightening, that’s why most ads show teachers explaining photosynthesis on the blackboard. The entire process is long and very very complicated; it’s a long chain of chemical reactions, photon displacements and so on.
‘Photosynthesis’ is from ‘photo’-meaning light and ‘synthesis’-meaning produce. The process of producing (energy) from light is called photosynthesis; simple. But practically it would be impossible without carbon di-oxide (CO2) and water as external ingredients. So if I were to name it, I would have called it ‘hydro-carbo-photosynthesis’ or something like that.
Here’s a simple presentation of the main operations in this process:
Photosynthesis is divided into 2 phases:
1) The light phase.
2) The dark phase
1) Light phase:
Water (H2O) is composed of hydrogen, oxygen and energy (bonds). First this water is broken to separate hydrogen, oxygen and energy by a part (P.S.II) of chlorophyll using light. Imagine this as a magnifying lens focusing light on water to break it into H (hydrogen) and O (oxygen)
The energy created due to breaking down of water is used by the chlorophyll to fuel it. Oxygen produced by the breakdown of water is released into the air.
The hydrogen combines with a particle to form a hydrogen-containing particle. Easy chemistry- you have a particle, you add hydrogen and voila- a hydrogen-containing particle.
Then, energy received from another part of the chlorophyll [P.S. I] helps 1 phosphate (a simple element) to unite with a 2 other phosphates, producing a 3-phosphate containing matter [ADP => ATP]. It’s easy, 1+2=3.
P.S. it’s never this easy.
Your half way there…keep it up.
2) The Dark phase:
Carbon di-oxide (CO2), a particle containing 1 carbon (the “C” of CO2), combines with a 5- carbon containing particle to produce a 6-carbon containing particle (5+1=6), called keto acid. This is unstable.
Keto acid instantly breaks down to 2 identical particles each containing 3-carbons (6/2=3). These are stable.
This 3-carbon containing particle combines with the hydrogen-containing particle obtained from the beginning of the light phase and the 3-phosphate containing particle [ATP] obtained from the end of light phase (remember?). These together form a very complex particle.
This very complex particle is finally reduced to form back the 5-carbon containing particle (that carbon di-oxide united with in the beginning of dark phase) and carbohydrate in the form of glucose.
You made it. That wasn’t so hard, was it?
The process is tons harder than described here. Chemical names have been omitted here and a lot of processes have been skipped. Molecules, atoms and electrons, photons have been referred to as particles and energy respectively.
The entire process of photosynthesis requires 6 molecules of carbon di-oxide and 12 molecules of water to produce 1 molecule of glucose [C6H12O6], 6 molecules of oxygen and 6 molecules of water.
This is only the description of the Calvin cycle, a type of photosynthesis. Besides this, there’s the Hatch and Slack’s pathway, the CAM pathway and so on. After photosynthesis, glucose is finally reduced to 686 Kcal of energy through aerobic respiration…..that’s another story.
--------------------------- The End-----------------------------
“Plants produce energy through the process of photosynthesis”-maybe I heard this before I was born! Photosynthesis is a long word, and to some people it’s frightening, that’s why most ads show teachers explaining photosynthesis on the blackboard. The entire process is long and very very complicated; it’s a long chain of chemical reactions, photon displacements and so on.
‘Photosynthesis’ is from ‘photo’-meaning light and ‘synthesis’-meaning produce. The process of producing (energy) from light is called photosynthesis; simple. But practically it would be impossible without carbon di-oxide (CO2) and water as external ingredients. So if I were to name it, I would have called it ‘hydro-carbo-photosynthesis’ or something like that.
Here’s a simple presentation of the main operations in this process:
Photosynthesis is divided into 2 phases:
1) The light phase.
2) The dark phase
1) Light phase:
Water (H2O) is composed of hydrogen, oxygen and energy (bonds). First this water is broken to separate hydrogen, oxygen and energy by a part (P.S.II) of chlorophyll using light. Imagine this as a magnifying lens focusing light on water to break it into H (hydrogen) and O (oxygen)
The energy created due to breaking down of water is used by the chlorophyll to fuel it. Oxygen produced by the breakdown of water is released into the air.
The hydrogen combines with a particle to form a hydrogen-containing particle. Easy chemistry- you have a particle, you add hydrogen and voila- a hydrogen-containing particle.
Then, energy received from another part of the chlorophyll [P.S. I] helps 1 phosphate (a simple element) to unite with a 2 other phosphates, producing a 3-phosphate containing matter [ADP => ATP]. It’s easy, 1+2=3.
P.S. it’s never this easy.
Your half way there…keep it up.
2) The Dark phase:
Carbon di-oxide (CO2), a particle containing 1 carbon (the “C” of CO2), combines with a 5- carbon containing particle to produce a 6-carbon containing particle (5+1=6), called keto acid. This is unstable.
Keto acid instantly breaks down to 2 identical particles each containing 3-carbons (6/2=3). These are stable.
This 3-carbon containing particle combines with the hydrogen-containing particle obtained from the beginning of the light phase and the 3-phosphate containing particle [ATP] obtained from the end of light phase (remember?). These together form a very complex particle.
This very complex particle is finally reduced to form back the 5-carbon containing particle (that carbon di-oxide united with in the beginning of dark phase) and carbohydrate in the form of glucose.
You made it. That wasn’t so hard, was it?
The process is tons harder than described here. Chemical names have been omitted here and a lot of processes have been skipped. Molecules, atoms and electrons, photons have been referred to as particles and energy respectively.
The entire process of photosynthesis requires 6 molecules of carbon di-oxide and 12 molecules of water to produce 1 molecule of glucose [C6H12O6], 6 molecules of oxygen and 6 molecules of water.
This is only the description of the Calvin cycle, a type of photosynthesis. Besides this, there’s the Hatch and Slack’s pathway, the CAM pathway and so on. After photosynthesis, glucose is finally reduced to 686 Kcal of energy through aerobic respiration…..that’s another story.
--------------------------- The End-----------------------------