by Kristyn Rooke

What is Photosynthesis?

Photosynthesis is the process by which plants use the energy from sunlight to produce sugar. Also, the conversion of unusable light energy into usuable chemical energy.

Formula: 6CO2 + 6H2O =light energy=> C6H12O6 + 6O2


Humans breathe in oxygen and breathe out carbon dioxide. Plants breathe in the carbon dioxide in the atmosphere and expel oxygen so that the cycle can continue

Light dependent cycles

The first stage of photosynthesis; the process by which plants capture and store energy from sunlight. In this process light energy is converted to chemical energy in the form of energy-carrying molecules of ATP and NADPH. ADP, NADP+, H2O, and light go into the cycle and oxygen is released.

Light independent cycle

Also known as the Calvin Cycle, converts carbon dioxide and other compounds into glucose. These reactions occur in the stroma. These reactions take the light-dependent reactions and perform further chemical processes on them. The cycle spends ATP as an energy source and consumes NADPH2 as reducing power for adding high energy electrons to make the sugar. Carbon Dioxide goes into the Calvin Cycle and oxygen is released.

Why is photosynthesis required for life?

Photosynthesis consumes Carbon Dioxide and releases Oxygen, which is important to animals because that is what we breathe. Photosynthesis also produces the food that the plant consumes. The level of carbon-dioxide in the environment largely depends on the process of photosynthesis. It produces fats, proteins, water soluble sugars such as maltose and sucrose. The plants depend on this glucose for their growth and energy.

Chloroplast Diagram


Chloroplasts are flat discs usually two to ten micrometers in diameter and one micrometer thick. The chloroplast has a two membrane envelope termed the inner membrane and outer membrane.The fluid within the chloroplast is called the stroma. Although most of the chloroplast's proteins are encoded by genes contained in the cell nucleus, some small portion of them are produced from tiny circular DNA and ribosomes present in the stroma. Within the stroma also are stacks of thylakoids, the sub-organelles where photosynthesis actually takes place. A stack of thylakoids is called a granum.

Functions of parts of Chloroplasts

  • Inner Membrane- Located under the smooth outer membrane.
  • outer membrane- The smooth outer covering of the chloroplast.
  • Thylakoid- A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.
  • granum - A stack of thylakoids in a chloroplast.
  • Stroma -The fluid of the chloroplast surrounding the thylakoid membrane.


Well, chloroplasts should get better benefits because if they weren't there to perform photosynthesis then we would probably die. That is our only means of oxygen, plants produce it through photosynthesis. And they also get rid of the carbon dioxide which is very bad for our health.

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