PHOTOSYNTHESIS - SCI & TECH
News: Scientists
Uncover the Earliest Fossil Evidence of Photosynthesis
What's in the news?
● Nearly
all animals need to breathe oxygen to survive. The life-sustaining gas they
inhale is made by plants, algae and cyanobacteria during photosynthesis.
Key takeaways:
● In
a new study published in the journal Nature, researchers have found cyanobacteria fossils from around 1.75
billion years ago that seem to have had the tools to make oxygen.
● They
contain thylakoid membranes,
structures in which photosynthesis takes place. The find marks the earliest fossil evidence of photosynthesis.
Photosynthesis:
●
Photosynthesis is a process by which autotrophs convert light energy into chemical energy, which is
later used to fuel cellular activities.
●
The chemical energy is stored in the form of sugars, which are created from water
and carbon dioxide.
Photosynthetic
Pigments:
●
Photosynthetic pigments such as chlorophyll a, chlorophyll b, carotene and xanthophyll.
●
All green plants and a few other autotrophic organisms
utilize photosynthesis to synthesize nutrients by using carbon dioxide,
water and sunlight.
Photosynthesis process requires several
factors such as:
1. Light Intensity:
●
Increased
light intensity results in a higher rate of photosynthesis. On the other hand,
low light intensity results in a lower rate of photosynthesis.
2. Concentration of CO2:
●
Higher
concentration of carbon dioxide helps in increasing the rate of photosynthesis.
Usually, carbon dioxide in the range of 300 – 400 PPM is adequate for
photosynthesis.
3. Temperature:
●
For
efficient execution of photosynthesis, it is important to have a temperature
range between 25° to 35° C.
4. Water:
●
As
water is an important factor in photosynthesis, its deficiency can lead to
problems in the intake of carbon dioxide.
●
The
scarcity of water leads to the refusal of stomatal opening to retain the amount
of water they have stored inside.
5. Pollution:
●
Industrial
pollutants and other particulates may settle on the leaf surface. This can
block the pores of stomata which makes it difficult to take in carbon dioxide.