Why does the uncovered part of the leaf turn blue?

In the experiment “light is essential for photosynthesis” the uncovered part of the leaf turn blue black after putting iodine solution. It is because, in the region which does not cover during the process of photosynthesis and it leads to the formation of Starch. Hence, the uncovered region is now composed of starch.

Why did the part of the leaf exposed to light turn black when covered in iodine?

Explanation. Starch is produced from glucose made during photosynthesis. Areas of the leaf exposed to the light should turn blue–black when iodine is added proving starch is present. This in turn, proves that photosynthesis occurred.

Why is the leaf exposed to sunlight before the experiment takes place?

To improve this experiment, the plant needs to be de-starched, and the leaves tested for the presence of starch. Once it is demonstrated that all starch has been utilized or removed, photosynthesis is allowed to take place by exposing the plant to sunlight.

Why the green Coloured areas of the leaf became blue black after the experiment?

Complete answer: In photosynthesis, the water molecules split into protons (H+) electrons, and oxygen gas. Additional Information: The inner part of the leaf turns blue-black on adding iodine solution which was originally green and shows that starch is present in the inner part of the leaf.

Is the uncovered part getting sunlight?

Iodine test in the black paper uncovered region show a positive result for the presence of starch i.e iodine in this region turns into blue-black color. The reason for this is that uncovered region gets sunlight and so this part of the leaf is able to synthesize starch.

Which experiment confirms light is essential for photosynthesis?

oxygen is released during photosynthesis. carbon dioxide is necessary for photosynthesis. light is essential for photosynthesis.

Does the presence of light essential in the process of photosynthesis?

Light is, thus, necessary for the process of photosynthesis to provide energy for the synthetic reactions. The synthesis of ATP molecules in presence of light is termed photo-phosphorylation.

Which part of the leaf turns blue black What about the remaining part in the black paper experiment?

when we put iodine solution onto the leaf, the part where the starch is present changes into blue-black colour. the part where the iodine solution is not put remains unchanged colour.

Why does a portion of leaf covered with black paper kept in sunlight give negative test for presence of starch?

The black paper covered region give a negative result for starch i.e. iodine in this region turns into brown color. The reason for this is black paper covered region gets no sunlight and so this part of the leaf is not able to synthesize starch.

Why light is essential for photosynthesis?

Light provides energy for the synthesis of glucose from carbon dioxide and water during photosynthesis. During light reaction, the chlorophyll entraps light and the solar energy is converted into chemical energy in the form of ATP molecules. This can happen because light energy is used to split water.

How light is essential for photosynthesis?

The most important factor for photosynthesis is light. The rate of photosynthesis depends on the quantity and quality of light. The chlorophyll molecule in green leaves absorb light, get excited and emit electrons. The emitted electrons are used in the production of adenosine triphosphate (ATP).

How do you prove that light is essential for photosynthesis?

Experiment to show that sunlight is necessary for photosynthesis

• Take a plant with destarched leaf.
• Leaf is partially covered with black paper on which a design is cut.
• Expose this plant to sunlight for few hours and perform a starch test with iodine solution.