Photosynthesis is the process by which
plants, some bacteria and some protistent use of the energy from sunlight
to produce glucose from carbon dioxide and water. This glucose can be
converted into private which releases adenine tri phosphate (ATP) by
cellular respiration. Oxygen is also formed.
What is Photosynthesis?
The word photosynthesis can be separated to make two smaller words:
“photo” which means light
“synthesis” which means putting together
Plants need food but they do not have to wait on people or animals to
provide for them. Most plants are able to make their own food whenever
they need it. This is done using light and the process is called
photosynthesis.
The Process of Photosynthesis
Photosynthesis takes place in the leaves of plants. The leaves are
made up of very small cells. Inside these cells are tiny structures
called
chloroplasts. Each chloroplast contains a green chemical called
chlorophyll which gives leaves their green color.
- Chlorophyll absorbs the sun’s energy.
- It is this energy that is used to split water molecules into hydrogen and oxygen.
- Oxygen is released from the leaves into the atmosphere.
- Hydrogen and carbon dioxide are used to form glucose or food for plants.
Some of the glucose is used to provide energy for the growth and
development of plants while the rest is stored in leaves, roots or
fruits for later use by plants.
Here is the process in greater detail:
Photosynthesis occurs in two stages commonly known as Light dependent Reactions and the Calvin Cycle.
Why is Photosynthesis Important?
Photosynthesis is important because it provides two main things:
Some of the glucose that plants produce during photosynthesis is
stored in fruits and roots. This is why we are able to eat carrots,
potatoes, apples, water melons and all the others. These foods provide
energy for humans and animals.
Oxygen that is produced during photosynthesis is released into the
atmosphere. This oxygen is what we breathe and we cannot live without
it.
While it is important that photosynthesis provides food and oxygen,
its impact on our daily lives is far more extensive. Photosynthesis is
so essential to life on earth that most living organisms, including
humans, cannot survive without it.
All of our energy for growth, development and physical activity comes
from eating food from plants and animals. Animals obtain energy from
eating plants. Plants obtain energy from glucose made during
photosynthesis.
Chloroplast ultrastructure
1. outer membrane
2. intermembrane space
3. inner membrane (1+2+3: envelope)
4. stroma (aqueous fluid)
5. thylakoid lumen (inside of thylakoid)
6. thylakoid membrane
7. granum (stack of thylakoids)
8. thylakoid (lamella)
9. starch
10. ribosome
11. plastidial DNA
12. plastoglobule (drop of lipids)
Photosynthesis Song