Science

 Endothermic and Exothermic reaction.

1) Endothermic Reaction,: An endothermic reaction is one that absorbs heat from its surroundings, causing a decrease in temperature.

example:

2) Exothermic Reaction: An exothermic reaction is one that releases heat into its surroundings, leading to a temperature increase.

Example:

Different between endothermic reaction and exothermic reaction.

1) Endothermic reaction.

.. Heat is absorbed by the system.

.. Temperature of the surrounding is decreased.

.. Favored by high temperature surroundings.

2) Exothermic reaction.

.. Heat is released by the system.

.. Temperature of the surrounding is increased.

.. favored by a low temperature surrounding.

Photosynthesis.

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy. It primarily occurs in the chloroplasts of plant cells, using chlorophyll, the green pigment that captures light.

Key Steps in Photosynthesis:

1. Light Absorption: Chlorophyll absorbs sunlight, primarily in the blue and red wavelengths.

2. Water Splitting: Light energy splits water molecules (H₂O) into oxygen (O₂), protons, and electrons.

3. Carbon Fixation: Carbon dioxide (CO₂) from the atmosphere enters the plant through small openings called stomata. In the Calvin cycle, CO₂ is combined with other molecules to eventually produce glucose (C₆H₁₂O₆).

4. Energy Conversion: The absorbed light energy is converted into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are used in the Calvin cycle.

Overall Equation:

The simplified overall equation for photosynthesis can be represented as:

$$6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2$$

Importance of Photosynthesis:

• Oxygen Production: Photosynthesis is responsible for producing the oxygen we breathe.
• Food Source: It forms the base of the food chain, providing energy for nearly all living organisms.
• Carbon Dioxide Utilization: It helps reduce CO₂ levels in the atmosphere, playing a role in climate regulation.

In summary, photosynthesis is a vital process that sustains life on Earth by converting solar energy into a usable form while also contributing to the oxygen-carbon dioxide balance in the atmosphere.