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PHOTOSYNTHESIS Light and Dark Reaction song

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Presentation on theme: "PHOTOSYNTHESIS Light and Dark Reaction song"— Presentation transcript:

1 PHOTOSYNTHESIS Light and Dark Reaction song

2 Lab Observation Seven plants are placed in separate boxes
Each plants are exposed to a different color light (different color cellophane that will cover them) Daily observations of the growth (height) of the plant and the number and size of its leaves will be recorded on the lab sheet This lab will take a period of 8 days

3 Review All living organisms require energy to carry out their life activities Living organisms obtain their energy by releasing the chemical bond energy stored in organic molecules Food products are the raw materials containing organic compounds

4 Continue Review Green plants receive their color because of the presence of the green pigment chlorophyll. The molecular structure of chlorophyll and the enzymes contained in the chloroplast allow the plant to capture the energy of the sun (solar energy) and to use this energy to convert water and carbon-dioxide to basic carbohydrates.

Photosynthesis is a process that in reality consists of two sets of reactions. The first reaction, known as the light reaction utilizes light energy to split water into hydrogen ions and oxygen gas. ATP and hydrogen ions produced in the light reaction (photolysis) is used in the second reaction, carbon fixation or the dark reaction. The dark reactions use ATP and hydrogen ions from the light reaction to convert atmospheric carbon dioxide into glucose. The process of photosynthesis is a chemical reaction. It is the most important chemical reaction on our planet.

Light energy Carbon dioxide + Water Glucose + oxygen

7 What is the equation for the chemical reaction of photosynthesis?
Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.

The process of changing light energy to chemical energy Energy stored as sugar Occurs in plants and some algae Plants need light energy, carbon dioxide and water Takes place in the chloroplasts, using chlorophyll, the green pigment in plants

9 What happens during photosynthesis?
Plants capture light energy and use that energy to make glucose Sunlight provides the energy needed by chlorophyll to change molecules of carbon dioxide and water into glucose Oxygen is also released in this reaction


11 What happens during photosynthesis
Carbon dioxide enters the leaf through holes called stomata Carbon dioxide combines with the stored energy in the chloroplasts through a chemical reaction to make glucose The sugar is moved through tubes in the leaf to the roots, stems and fruits of the plants Some of the sugar is used right away by the plant for energy; some is stored as starch; and some is built into plant tissue

12 Why is this important to us?
We cannot make our own food (glucose, energy), we must get our food from plants. Plants are the first step in the food chain. Plants are able to use a source of energy, such as sunlight, to provide food directly form simple inorganic molecules are known as autotrophs.

13 Why is this important to us?
The oxygen released during photosynthesis is necessary for all living things video wrap up

14 Photosynthesis Stage 2 The Dark Reaction

15 The dark reactions do not require direct light
Dark reaction occurs in the stroma Carbon dioxide is converted to sugar using ATP and NADPH. This process is known as Carbon Fixation or the Calvin Cycle.


17 Carbon dioxide is combined with a 5 carbon sugar creating a 6 carbon sugar
The 6 carbon sugar is eventually broken down into two molecules called glucose and fructose. These two molecules make sugar

18 Summary Photosynthesis is a process in which light energy is converted to chemical energy. It means “Putting Together with Light.” This process requires Sunlight as a source of energy. In plants, photosynthesis occurs within the chloroplasts where the green pigment chlorophyll can be found.

19 Photosynthesis consists of two stages:
a. The Light Reaction b. The Dark Reaction Light Reaction converts light into energy (ATP and NADHP) Dark Reaction uses the energy and carbon dioxide to produce sugar

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